Elite.Parts Manufacturers S SEMTECH SC4808B
About product Specifications Features Datasheet FAQ

SEMTECH SC4808B

Image of SEMTECH SC4808B

Description

Semtech SC4808B High performance Dual Ended PWM Controller

Part Number

SC4808B

Price

Request Quote

Manufacturer

SEMTECH

Lead Time

Request Quote

Category

PRODUCTS - S

Specifications

Package

MSOP-10

Peak Gate Drive Current

.25

Vin (V) Max

18

Vin(V) Min

4.5

Features

Datasheet

pdf file

SC4808A-626386827.pdf

469 KiB

Extracted Text

SC4808A/B High Performance Dual Ended PWM Controller POWER MANAGEMENT Description Features The SC4808A/B is a dual-ended, high frequency, integrated ‹ 120µA starting current PWM controller, optimized for isolated applications that ‹ Pulse by pulse current limit require minimum space. It can be configured for current ‹ Programmable operation up to 1MHz or voltage mode operation with required control circuitry ‹ Internal soft start where secondary side error amplifier is used. ‹ Programmable line undervoltage lockout ‹ Over current shutdown Some of the key features are high frequency operation of ‹ Dual output drive stages on push-pull configuration 1 MHz that allows the use of smaller components thus ‹ Programmable internal slope compensation saving cost and valuable board space. An internal ramp ‹ Programmable mode of operation (peak current mode on the Current Sense pin allows Internal Slope or voltage mode) Compensation programmed by an external resistor. Other ‹ External frequency synchronization features include programmable frequency up to 1MHz, Pulse by Pulse current and Line Monitoring Input with ‹ Bi-phase mode of operation Hysteresis to reduce stress on the power components. ‹ -40 to 105 °C operating temperature ‹ 10 Pin MSOP lead free package available. WEEE and A unique oscillator is used to synchronize two SC4808’s to RoHS compliant. work out of phase. This minimizes the input and output ripple thus reducing noise on the output line and reducing Applications stress and size of input/output filter components. The dual ‹‹‹‹‹ Telecom equipment and power supplies outputs can be configured in Push-Pull, Half Bridge and ‹‹‹‹‹ Networking power supplies Full Bridge format with programmable dead time between ‹ Industrial power supplies two outputs depending on the size of the timing ‹ Push-pull converter components. ‹ Half bridge converter ‹ Full bridge converter The SC4808 also features a turn on threshold of 12V for SC4808A and 4.4V for SC4808B. They are available in ‹ Isolated VRM’s MSOP-10 packages. Typical Application Circuit Vo Vin Gnd_Out RSENSE Gnd_In OUTA RC OUTB REF CS VCC FB SYNC SYNC LUVLO GND SC4808 Revision October 20, 2005 1 www.semtech.com SC4808A/B POWER MANAGEMENT Absolute Maximum Ratings Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not implied. Pl arameter Sm ymboMs aximu Unit SV upply Voltage -V 0.5 to18 CC SI upply Current 2A 0 m CC SYNC, RC,CS, LUVLO, REF to GND -V 0.5 to 7 FV B to GND -0.5 to (V+V 0.5) FB REF RI EF Current 1A 0 m REF OV UTA/OUTB to GND -V 0.5 to 18 OUTA/B OI UTA/OUTB Source Current (peak) -A 250 m source OI UTA/OUTB Sink Current (peak) 2A 50 m sink Power Dissipation at T=P 25°C 1W .105 A D Thermal Resistance 1W 13.1 °C/ θ JA JT unction Temperature -C 40 to 150 ° J ST torage Temperature Range -C 65 to 150 ° STG LT ead Temperature (Soldering) 10 Sec. +C 300 ° LEAD EV SD Rating (Human Body Model) 2V k ESD Electrical Characteristics Unless specified: VCC = 12V; CL = 100pF; T = -40°C to 105°C A Ps arameter Tn est Condition Mp i Tx y Mt a Uni PWM M, aximum Duty Cycle Fosc = 50kHz, FB = 5V 49 8 405% Measured at OUTA or OUTB M, inimum Duty Cycle Fosc = 50kHz, FB = 1.5V 0% Measured at OUTA or OUTB Current Sense Gain 3 Maximum Input Signal 45 75 55 2 5V 7 m CS to Output Delay 1s 00 n Over Current Threshold .0 850 .1 95 V Internal Slope Compensation 2k 5 Ω Resistor FB to CS Offset 10 .3010 .5 1V .7 Output OUT Low Level 00.0 5 .V 7 OUT High Level 15 1.010 1.2 1V 2.0 Rise Time 2s 5 n Fall Time 2s 5 n  2005 Semtech Corp. 2 www.semtech.com SC4808A/B POWER MANAGEMENT Electrical Characteristics (Cont.) Unless specified: VCC = 12V; CL = 100pF; T = -40°C to 105°C A Ps arameter Tn est Condition Mp i Tx y Mt a Uni VCC Under Voltage Lockout Start Threshold (SC4808A) 12 0.75151V 3.2 Hysteresis (SC4808A) 35 .5 45 . 5V . Start Threshold (SC4808B) 40 .0 45 .4 4V . Hysteresis (SC4808B) 40 0 701V 1 m Line Under Voltage Lockout Sk tart Threshold R23 = 14 Ω, R33 = 10kΩ(% see page 14)-F 3 V% RE +V 3 5.6% of Hk ysteresis R23 = 14 Ω, R33 = 10kΩ (see page 14) mV VREF Soft Start Internal Soft Start Ramp 2V 00 µs/ Sk oft Start Duration (SC4808A) Rcs = 7 Ω 1s 10 µ (See formula in the application information section on page 21) Sk oft Start Duration (SC4808B) Rcs = 1 Ω 1s 2 µ (See formula in the application information section on page 21) Soft Start Delay 1s 40 µ Oscillator OR scillator Frequency = 11kΩ, C=0 200pF 40 5 50 0 5z 5 KH osc osc Oscillator Ramp VREF/2 V +0.25 RC pin to GND capacitance 2F 2 p Oscillator Frequency Range 50 0 1z 00 KH Sync/CLOCK Clock SYNC Threshold(SC4808A) 1V .6 Clock SYNC Threshold(SC4808B) 1V .0 Sync Frequency Range F*z 1.3 KH osc Bandgap Reference Voltage (SC4808A) 40 .75 55 . 5V .2 Reference Current (SC4808A) 5A m Reference Voltage (SC4808B) 25 .97030 .12 3V .28 R) eference Current (SC4808B 5A m Overall Sd tartup Current V0 CC < start threshol 1A 5 µ OV perating Supply CurrentF7 B = 0V, CS = 0 mA VA CC Zener Shunt Voltage I6 DD = 10m 1V  2005 Semtech Corp. 3 www.semtech.com SC4808A/B POWER MANAGEMENT Pin Configuration Ordering Information Pe art NumberPT ackag Temp. Range ( ) A Top View (1) SC4808AIMSTR (1)(2) SC4808AIMSTRT MC SOP-10 -40°C to 105° (1) SC4808BIMSTR (1)(2) SC4808BIMSTRT Notes: (1) Only available in tape and reel packaging. A reel contains 2500 devices. (2) Lead free product. This product is fully WEEE and (MSOP-10) RoHS compliant.  2005 Semtech Corp. 4 www.semtech.com SC4808A/B POWER MANAGEMENT Pin Descriptions FB: The inverting input to the PWM comparator. Stray in- LUVLO: Line undervoltage lockout pin. An external resis- ductances and parasitic capacitance should be minimized tive divider will program the undervoltage lockout level. The by utilizing ground planes and correct layout guide lines external divider should be referenced to the quiet analog ground (see page 22). During the LUVLO, the driver out- (see page 22). puts are disabled and the softstart is reset. This pin can REF: Bandgap reference output It should be by passed with also function as an Enable/Disable. a 2.2uF low ESR capacitance, right at the IC pin. CS: Current sense input and internal slope compensation SYNC: SYNC is a positive edge triggered input with a thresh- are both provided via the CS pin. The current sense input from a sense resistor is used for the peak current and old set to 1.6V (SC4808A), and 1.0V (SC4808B). overcurrent comparators. An internal 1 to 3 feed back volt- In a single controller operation, SYNC could be grounded age divider provides a 3X amplification of the CS signal. or connected to an external synchronization clock within the SYNC frequency range (see page 3). In the Bi-Phase This is used for comparison to the external error amplifier operation mode SYNC pins could be connected to the Cosc signal. If an external resistor is connected from CS to the (Timing Capacitors) of the other controller. This will force current sense resistor, the internal current source will pro- an out of phase operation (see page 15). vide a programmable slope compensation. The value of the resistor will determine the level of compensation. At GND: Device power and analog ground. Careful attention higher compensation levels, voltage mode of operation can should be paid to the layout of the ground planes (see page be achieved. 22). RC: The oscillator programming pin. The oscillator should OUTA and OUTB: Out of phase gate drive stages. The be referenced to a stable reference voltage for an accu- driver’s peak source and sink current drive capability of rate and stable frequency. Only two components are re- 100mA, enables the use of an external MOSFET driver or quired to program the oscillator, a resistor (tied to Vref and a NPN/PNP transistor buffer. RC), and a capacitor (tied to the RC and GND). The follow- The oscillator RC network programs the oscillator frequency, ing formula can be used for a close approximation of the which is twice the OUTA/OUTB frequency. To insure that oscillator frequency. the outputs do not overlap, a dead time can be generated 1 1 F ≅ F ≅ OSC_A OSC_B between the two outputs by sizing the oscillator timing ca- R C × 0.8 R C × 0.9 OSC TOT OSC TOT pacitor (see page 14). where: VCC: The supply input for the device. Once VCC has ex- ceeded the UVLO limit, the internal reference, oscillator, C =C +C +C TOT OSC SC4808 Circuit drivers and logic are powered up. A low ESR capacitance, should be used for decoupling right at the IC pin to mini- C ≅ 22pF mize noise problems. SC4808 Where the frequency is in Hertz, resistance in ohms, and capacitance in farads. The recommended range of timing resistors is between 10 kohm and 200kohm and range of timing capacitors is between 100pF and 1000pF. Timing resistors less than 10 kohm should be avoided. Refer to layout guide lines on page 22 to achieve best re- sults.  2005 Semtech Corp. 5 www.semtech.com SC4808A/B POWER MANAGEMENT Block Diagram VCC CS Slope Comp. OVER CURRENT Peak Current OUTA Enable OSC SQ R Disable 500mv Q T SQ Q LUVLO R REF Bandgap SOFT UVLO START R OUTB SYNC 2R LUVLO GND LUVLO FB RC SYNC Marking Information Top Mark Top Mark ABOA ABOB yyww yyww Bottom Mark Bottom Mark xxxx xxxx xxxx xxxx SC4808AIMSTR, SC4808AIMSTRT SC4808BIMSTR, SC4808BIMSTRT yyww = Datecode (Example: 9912) xxxx = Semtech Lot # (Example: E901 xxxx 01-1)  2005 Semtech Corp. 6 www.semtech.com SC4808A/B POWER MANAGEMENT SC4808A Typical Characteristics (SC4808A) 100 1.58 FB to CS Offset Start up Iq, Vcc = 10V 1.56 95 1.54 90 1.52 85 1.50 1.48 80 1.46 75 1.44 70 1.42 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 Ta (°C) Ta (°C) Iq (start up) vs. Temperature FB to CS Offset vs. Temperature 4.40 1000 Operating Iq, Vcc = 12V Max Current Sense Signal Operating Iq, Vcc = 15V Over Current Signal 4.30 900 800 4.20 4.10 700 4.00 600 3.90 500 3.80 400 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 Ta (°C) Ta (°C) Iq (operating) vs. Temperature Current sense vs. Temperature 5.110 14 Vcc UVLO (Rising) Reference Vcc UVLO (Falling) 5.100 13 5.090 12 5.080 11 5.070 5.060 10 5.050 9 5.040 8 5.030 5.020 7 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 Ta (°C) Ta (°C) Reference vs. Temperature Vcc UVLO vs. Temperature  2005 Semtech Corp. 7 www.semtech.com Iq (mA) Iq(uA) Reference (V) Vcc UVLO (V) Current Sense (mV) FB to CS offset (V) SC4808A/B POWER MANAGEMENT SC4808A Typical Characteristics (Cont.) 5.00 1400 Vcc UVLO Oscillator Frequency 1MHz (Hysteresis) 4.80 Oscillator Frequency 500kHz 1200 4.60 4.40 1000 4.20 4.00 800 3.80 600 3.60 3.40 400 3.20 3.00 200 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 Ta (°C) Ta (°C) Vcc UVLO Hysteresis vs. Temperature Oscillator Frequency vs. Temperature 1000 5.030 LUVLO (Rising) Sync. Frequency @ Fosc = 500kHz 5.025 900 5.020 5.015 800 5.010 700 5.005 5.000 600 4.995 500 4.990 4.985 400 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 Ta (°C) Ta (°C) Line UVLO vs. Temperature Synchronization Frequency vs. Temperature 335 49.3 LUVLO (Hysteresis) Maximum Duty Cycle 330 49.3 325 49.2 320 49.2 315 310 49.1 305 49.1 300 49.0 295 290 49.0 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 Ta (°C) Ta (°C) Line UVLO Hysteresis vs. Temperature Maximum Duty Cycle vs. Temperature  2005 Semtech Corp. 8 www.semtech.com LUVLO Hysteresis (mV) Vcc UVLO Hysteresis (V) LUVLO (V) Maximum Duty Cycle (%) Synchronization Frequency (kHz) Oscillator Frequency (kHz) SC4808A/B POWER MANAGEMENT SC4808A Typical Characteristics (Cont.) 220 Soft Start Delay Time 200 180 160 140 120 100 80 -40 -25 -10 5 20 35 50 65 80 95 110 125 Ta (°C) Soft Start Delay time vs. Temperature  2005 Semtech Corp. 9 www.semtech.com Soft Start Delay Time (us) SC4808A/B POWER MANAGEMENT SC4808B Typical Characteristics (SC4808A) 100.0 1.69 FB to CS Offset Start up Iq, Vcc = 4V 1.68 95.0 1.67 90.0 1.66 1.65 85.0 1.64 80.0 1.63 1.62 75.0 1.61 70.0 1.60 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 Ta (°C) Ta (°C) Iq (start up) vs. Temperature FB to CS Offset vs. Temperature 3.90 1100 Operating Iq, Vcc = 5V Max Current Sense Signal Over Current Signal Operating Iq, Vcc = 5.25V 1000 3.85 900 3.80 800 3.75 700 3.70 600 3.65 500 3.60 400 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 Ta (°C) Ta (°C) Iq (operating) vs. Temperature Current sense vs. Temperature 3.22 4.500 Vcc UVLO (Rising) Reference, Vcc = 5V Vcc UVLO (Falling) 3.21 4.450 3.2 4.400 3.19 4.350 3.18 4.300 3.17 4.250 3.16 4.200 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 Ta (°C) Ta (°C) Reference vs. Temperature Vcc UVLO vs. Temperature  2005 Semtech Corp. 10 www.semtech.com Reference (V) Iq(uA) Iq (mA) Current Sense (mV) FB to CS offset (V) Vcc UVLO (V) SC4808A/B POWER MANAGEMENT SC4808B Typical Characteristics (Cont.) 100 1400 Oscillator Frequency 1MHz Vcc UVLO (Hysteresis) Oscillator Frequency 500kHz 98 1200 96 1000 94 92 800 90 600 88 400 86 84 200 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 Ta (°C) Ta (°C) Vcc UVLO Hysteresis vs. Temperature Oscillator Frequency vs. Temperature 664 3.170 LUVLO (Rising) Sync. Frequency @ Fosc = 500kHz 3.165 662 3.160 660 3.155 3.150 658 3.145 656 3.140 3.135 654 3.130 652 3.125 3.120 650 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 Ta (°C) Ta (°C) Line UVLO vs. Temperature Synchronization Frequency vs. Temperature 49.5 140 LUVLO (Hysteresis) Maximum Duty Cycle 135 49.5 130 49.5 125 49.4 120 49.4 115 49.4 110 49.4 105 100 49.4 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 Ta (°C) Ta (°C) Line UVLO Hysteresis vs. Temperature Maximum Duty Cycle vs. Temperature  2005 Semtech Corp. 11 www.semtech.com LUVLO Hysteresis (mV) LUVLO (V) Vcc UVLO Hysteresis (mV) Maximum Duty Cycle (%) Synchronization Frequency (kHz) Oscillator Frequency (kHz) SC4808A/B POWER MANAGEMENT SC4808B Typical Characteristics (Cont.) 180 Soft Start Delay Time 170 160 150 140 130 120 110 100 90 80 -40 -25 -10 5 20 35 50 65 80 95 110 125 Ta (°C) Soft Start Delay time vs. Temperature  2005 Semtech Corp. 12 www.semtech.com Soft Start Delay Time (us) SC4808A/B POWER MANAGEMENT Application Information THEORY OF OPERATION The SC4808 is a versatile double ended, high speed, low overcurrent comparators. An internal 1 to 3 feedback volt- power, pulse width modulator that is optimized for applica- age divider provides a 3X amplification of the CS signal. tions requiring minimum space. This is used for comparison to the external error amplifier The device contains all of the control and drive circuity re- signal. If an external resistor is connected from CS to the quired for isolated or non isolated power supplies where current sense resistor, the internal current source will pro- an external error amplifier is used. A fixed oscillator fre- vide a programmable slope compensation. The value of quency (up to 1MHz) can be programmed by an external the resistor will determine the level of compensation. At RC network. higher compensation levels, voltage mode of operation can The SC4808 is a peak current or voltage mode controller, be achieved. The error amplifier signal at the FB pin will be depending on the amount of slope compensation, used in conjunction with the CS signal to achieve regula- programmable with only one external resistor. The cycle by tion. cycle peak current limit prevents core saturation when a Two levels of undervoltage lockout are also available. The transformer is used for isolation while the overcurrent LUVLO (line under voltage lockout) pin via an external re- circuitry initiates the softstart cycle. sistive divider will program the undervoltage lockout level. The SC4808 dual output drive stages are arranged in a During the LUVLO, the driver outputs are disabled and the push-pull configuration. Both outputs switch at half the softstart is reset. oscillator frequency using a toggle flip flop. The dead time Once VCC has exceeded the UVLO (VCC under voltage lock- between the two outputs is programmable depending on out) limit, the internal reference, oscillator, drivers and logic the values of the timing capacitor and resistors, thus limiting are powered up. each output stage duty cycle to less than 50%. The SC4808 also provides flexibility with programmable SYNC is a positive edge triggered input with a threshold LUVLO thresholds, with built-in hysteresis. set to 1.6V (SC4808A), and 1.0V (SC4808B). By connecting an external control signal to the SYNC pin, SUPPLY the internal oscillator frequency will be synchronized to the positive edge of the external control signal. In a single con- A single supply, VCC is used to provide the bias for the troller operation, SYNC should be grounded or connected internal reference, oscillator, drivers, and logic circuitry of to an external synchronization clock within the SYNC fre- SC4808. quency range (see page 3). In the Bi-phase operation mode a very unique oscillator PWM CONTROLLER is utilized to allow two SC4808 to be synchronized together and work out of phase. This feature is setup by SC4808 is a double ended PWM controller that can be simple connection of the SYNC input to the RC pin of the used in voltage or current mode applications. Two voltage other part. The fastest oscillator automatically becomes options are available for the SC4808. The SC4808A ver- the master, forcing the two PWMs to operate out of sion has a typical VCC under voltage of 12.0V and a 5V phase. This feature minimizes the input and output reference. The SC4808B version provides a 4.4V VCC UVLO, ripples, and reduces stress on the capacitors. and a 3.125V reference. The oscillator frequency is pro- grammed by a resistor and a capacitor network connected to an external reference provided by the SC4808. The two DO eviceTe yp. Vcc UVL Reference Voltag outputs, OUTA and OUTB, are 180 degrees out of phase and run at half of the oscillator frequency. SC4808A1V 2.0V 5 An external error amplifier will provide the error signal to SC4808B4V .4V 3.125 the FB pin of the SC4808. The current sense input and internal slope compensation are both provided via the CS pin. The current sense input from a sense resistor is used for the peak current and  2005 Semtech Corp. 13 www.semtech.com SC4808A/B POWER MANAGEMENT Application Information (Cont.) VCC UNDER VOLTAGE LOCK OUT OSCILLATOR Depending on the application and the voltages available, The oscillator frequency is set by connecting a RC network the SC4808A (UVLO = 12.0V), or the SC4808B (UVLO = as shown below. 4.4V) can be used to provide the VCC undervoltage lock out function to ensure the converters controlled start up. Before the VCC UVLO has been reached, the internal refer- REF VCC 0 ence, oscillator, OUTA/OUTB drivers, and logic are disabled. C26 2.2u,16V LINE UNDER VOLTAGE LOCK OUT R27 U4 R28 15k 5 6 10 REF GND 4 7 The SC4808 also provides a line undervoltage (LUVLO = FB OUTB 3 8 Vref) function. The LUVLO pin is programmed via an exter- CS OUTA 2 9 RC VCC nal resistor divider connected as shown below. The actual C31 C33 1 10 200p SYNC LUVLO 0.1u,25V start-up voltage can be calculated by using the equation below: SC4808 0 SYNC 56.2k 10k Vin R23 R33 () R23 + R33 V = V × Startup REF R33 The oscillator has a ramp voltage of about Vref/2. The os- cillator frequency is twice the frequency of the OUTA and OUTB gate drive controls. R24 10k REF VCC 15 C26 The oscillator capacitor C31 is charged by a current sourced 2.2u,16V from the Vref through R27. Once the RC pin reaches about R25 18 Vref/2, the capacitor is discharged internally by the R26 R27 U4 R28 2.2k 15k 5 6 10 REF GND SC4808. It should be noted that larger capacitor values 4 7 FB OUTB will result in a longer dead time during the down slope of 3 8 CS OUTA the ramp. C29 2 9 RC VCC The following equation can be used as an approximation 82p C31 C33 1 10 200p SYNC LUVLO 0.1u,25V of the oscillator frequency and the Dead time: SC4808 SYNC 1 1 56.2k 10k F ≅ F ≅ OSC_A OSC_B R C × 0.8 R C × 0.9 OSC TOT OSC TOT Vin R23 R33 where: REFERENCE C =C +C +C TOT OSC SC4808 Circuit A 5V (SC4808A) or a 3.125V(SC4808B) reference voltage is available that can be used to source a typical current of C ≅ 22pF SC4808 5mA to the external circuitry. The Vref can be used to pro- C × V × 0.5 OSC REF T ≅ vide the oscillator RC network with a regulated bias. deadtime −3 3⋅10 The recommended range of timing resistors is between 10 kohm and 200kohm, range of timing capacitors is between 100pF and 1000pF. Timing resistors less than 10 kohm should be avoided.  2005 Semtech Corp. 14 www.semtech.com SC4808A/B POWER MANAGEMENT Application Information (Cont.) FEED BACK SYNC/Bi-Phase operation The error signal from the output of an external error ampli- In noise sensitive applications where synchronization of fier such as SC431 or SC4431 is applied to the inverting the oscillator frequency to a reference frequency is required, input of the PWM comparator at the FB pin either directly the SYNC pin can accept the external clock. By connecting or via an opto coupler for the isolated applications. For best an external control signal to the SYNC pin, the internal os- stability, keep the FB trace length as short as possible. cillator frequency will be synchronized to the positive edge of the external control signal. SYNC is a positive edge trig- Vref gered input with a threshold set to 1.6V (SC4808A), and Vout Vout 1.0V (SC4808B). R37 C35 2.2k R34 R32 6 3 C36 R35 FB C40 22pF In a single controller operation, SYNC should be grounded 5 4 R36 1 5 C37 or connected to an external synchronization clock within MOCD207 4 C38 C39 the SYNC frequency range (see page 3). 0.1u 22n SC4431 R38 Vref 2 OUTA (PWM1) OUTB (PWM1) The signal at the FB pin is then compared to the 3X ampli- fied signal from the current sense/ slope compensation CS pin. Matched out of phase signals are generated to OUTA (PWM2) control the OUTA and OUTB gate drives of the two phases. A single ramp signal is used to generate the control sig- OUTB (PWM2) nals for both phases, hence achieving a tightly matched per phase operation. Voltages below 1.5V at the FB pin, will produce a 0% duty cycle at the OUTA/OUTB gate drives. This offset is to pro- REF REF vide enough head room for the opto coupler used in iso- lated applications. Rosc1 Rosc2 U1 U2 5 6 5 6 REF GND REF GND 4 7 4 7 GATE DRIVERS FB OUTB FB OUTB 3 8 3 8 CS OUTA CS OUTA 2 9 2 9 RC VCC RC VCC OUTA and OUTB are out of phase bipolar gate drive output Cosc1 1 10 Cosc2 1 10 SYNC LUVLO SYNC LUVLO stages, that are supplied from VCC and provide a peak source/sink current of about 100mA. Both stages are ca- SC4808 SC4808 pable of driving the logic input of external MOSFET drivers or a NPN/PNP transistor buffer. The output stages switch at half the oscillator frequency. When the voltage on the RC pin is rising, one of the two outputs is high, but during In the Bi-phase operation mode a very unique oscillator fall time, both outputs are off. This “dead time” between is utilized to allow two SC4808’s to be synchronized the two outputs, along with a slower output rise and fall together and work out of phase. This feature is set up by time, insures that the two outputs can not be on at the a simple connection of the SYNC input to the RC pin of same time. The dead time is programmable and depends the other part. The fastest oscillator automatically upon the timing capacitor. becomes the master, forcing the two PWMs to operate It should be noted that if high speed/high current drivers out of phase. This feature minimizes the input and such as the SC1301 are used, careful layout guide lines output ripples, and reduces stress on the capacitors. must be followed in order to minimize stray inductance,  2005 Semtech Corp. 15 www.semtech.com SC4808A/B POWER MANAGEMENT Application Information (Cont.) which might cause negative voltages at the output of the drivers. This negative voltage can be clamped to a reason- able level by placing a small Schottky diode directly at the output of the driver as shown below. VCC EN SC1301A U3 3 5 C23 F VCC 0.1u 1 4 Gate_B C26 2.2u,16V D_B 2 U4 R28 5 6 10 REF GND 4 7 FB OUTB 3 8 CS OUTA VCC EN 2 9 RC VCC SC1301A C33 1 10 U6 3 5 SYNC LUVLO 0.1u,25V C34 SC4808 0.1u SYNC 1 4 Gate_A 56.2k 10k D_A Vin R23 R33 2 OVER CURRENT Two levels of over current protection are provided by the SC4808. The current information is sensed at the CS pin and compared to a peak current limit level of 525mV. If the 525mV limit is exceeded, the OUTA and OUTB pulse widths and duty cycle is reduced until the CS pin reaches a second threshold of 950mV. At that point, the OUTA and OUTB are disabled, and after a delay of 140µs, the inter- nal softstart sequence is started. After the softstart dura- tion (see page 21 for calculation of softstart time), normal operation is achieved, unless the over current condition is still present.  2005 Semtech Corp. 16 www.semtech.com SC4808A/B POWER MANAGEMENT Application Information (Cont.) SLOPE COMPENSATION (Current or Voltage mode of operation) In applications where a current mode control is used for regulation, the peak inductor current information is used to produce the average output current. If a small perturbation due to changes in supply voltage or noise pick up is gener- ated, instability may occur if the duty cycle is >50%. This phenomenon is graphically shown below. The inductor current and disturbed inductor current are shown for three different duty cycles conditions. The top wave form shows the applications where the duty cycle D is less than 50%. As shown, even if an error is introduced, after only a few cycles the error converges to zero. The second wave form shows the case where D = 50%. Under this condition, even though the error does not completely disappear, it stays constant and is not getting larger. This will be seen as jitter at the inductor voltage. The bottom wave form shows D>50%. As shown, a very small error results in a much larger error only after a few cycles. This will cause instability in the converter and the average output inductor current. The output load will not be able to be kept in regulation. Instability in current mode operation due to Duty cycle >50% iL : Small Inductor current perturbation : Inductor current I L D<50% I i L L Note: After afew cycles the perturbation disappears and stable operation returns. Time D=50% iL I i L L Note: After afew cycles the perturbation is still present, although this will cause jitter, but there is no instability. Time D>50% IL iL iL Note: After afew cycles the perturbation becomes larger, and causes instability. Time  2005 Semtech Corp. 17 www.semtech.com Error Error Error SC4808A/B POWER MANAGEMENT Application Information (Cont.) The instability can be corrected by modification of the peak achieved. As it can be calculated from the second formula current information slope. One of the methods to alter the below, a 100% voltage mode operation can be achieved by peak current information is to add a positive going ramp to choosing R to be greater than 6.25K ohms. Also if a slope comp the output of the current sensing circuitry. 100% current mode of operation is required, R is slope comp The SC4808 achieves this by using an internal slope com- reduced to zero and the contribution from the internal ramp pensation circuit. The oscillator ramp is internally buffered is completely eliminated. and an internal 25kOhms resistor in conjunction with an external resistor at the CS pin will program the level of slope () R + R slope_Comp sense compensation. V × Ramp () R + R + R slope_Comp sense internal %Slope_ Comp= V CS Current Transformer or N = 100 10k  0.2 ×() %slope_ Comp  R ≅ R • R external internal   REF () 1− 0.2 × %slope_ Comp   D C 2.2u,16V Rsense Next page illustrates how the buffered oscillator ramp is Rosc RSlope Comp used to modify the sensed inductor current. 15k 5 6 REF GND It should be noted that in order for the slope compensa- 4 7 FB 25k 3 tion to be effective, the current sensed signal slope should CS Cfilter 2 be at least 50% less steeper than the oscillator positive RC Cosc 82p 1 SYNC ramp slope. The slope will include the magnetizing current 200p of the transformer and the inductor output current in iso- SC4808 lated applications. In non-isolated applications, the slope RSlope Comp value will determine the Mode of operation (Voltage or Current) will only include the inductor output current. The Peak current information is sensed and the result is realistically summed to the buffered oscillator ramp, as shown above. The value of the external resistor R slope comp will determine the percentage of the slope compensation. As the value for R is reduced, the current informa- slope comp tion becomes more dominant and the mode of operation becomes more current mode. At the same time the slope of the current information is modified to provide the slope compensation. If the R is increased, the internal ramp becomes the slope comp dominant signal and more voltage mode of operation is  2005 Semtech Corp. 18 www.semtech.com SC4808A/B POWER MANAGEMENT Application Information (Cont.) i : Small Inductor current perturbation L Slope Compensation generation from : Inductor current Buffered Oscillator Ramp I L I : Sensed Mosfet current Sense D>50% I : Summation of Isense and slope compensation, at the CS pin of the SC4808. Note: Below wave forms are not to scale. CS I L ISense Buffered Oscillator Ramp I CS  2005 Semtech Corp. 19 www.semtech.com SC4808A/B POWER MANAGEMENT Application Information (Cont.) Below the benefits from the slope compensation become apparent. The top wave form shows the stable operation before the perturbation. The second wave form shows the perturbation and the instability caused from it if no slope compensation is added to the current information. The last wave form shows the slope compensation and the effect of it. The increase in the slope of the current information results in an early termination of the inductor current, hence a reduction in the amount of error. As the cycle is repeated, the perturbation is reduced and finally eliminated. δ Stable current mode operation with Slope i : Small Inductor current perturbation L Δ Compensation : Inductor current IL I : Sensed Mosfet current Sense D>50% I : Summation of Isense and slope compensation, at the CS pin of the SC4808. CS Stable operation ( no perturbation) Error Signal from Error amplifier Δ I L ISense Note: After a few cycles the perturbation becomes larger, and causes instability. Instable operation ( with perturbation) Error Signal from Error amplifier Δ I L δ i L I Sense Note: After a few cycles the perturbation disappears and stable operation returns. Stable operation (Slope Compensation Added) Error Signal from Error amplifier Δ IL δ ICS i L  2005 Semtech Corp. 20 www.semtech.com SC4808A/B POWER MANAGEMENT Application Information (Cont.) START UP SEQUENCE SOFT START Initially during the power up, the SC4808 is in under volt- During start up of the converter, the discharged output ca- age lock out condition. As the Vcc supply exceeds the UVLO pacitor and the load current have large supply current re- limit of the SC4808, the internal reference, oscillator, and quirements. To avoid this a soft start scheme is usually logic circuitry are powered up. implemented where the duty cycle of the regulator is gradu- The OUTA and OUTB drivers are not enabled until the line ally increased from 0% until the soft start duration is under voltage lock out limit is reached. At that point, once elapsed. the FB pin is above 1.5V, soft start circuitry starts the out- SC4808 has an internal soft start circuit that limits the put drivers, and gradually increases the duty cycle from duty cycle for a duration approximated by the formula be- 0%. The soft start duration is internally set (see formula in low. Also the soft start circuitry is activated if an over cur- Soft Start section). rent condition occurs. After an over current condition, OUTA As the output voltage starts to increase, the error signal and OUTB are disabled and kept low for a duration of about from the error amplifier starts to decrease. If isolation is 140µs. After the delay, the OUTA and OUTB are enabled required, the error amplifier output can drive the LED of while the soft start limits the duty cycle. If the over current the opto isolator. The output of the opto is connected in a condition persists, the soft start cycle repeats indefinitely. common emitter configuration with a pull-up resistor to a Approximate internal soft start duration can be calculated reference voltage connected to the FB pin of the SC4808. as below: The voltage level at the FB pin provides the duty cycle nec- VREF   essary to achieve regulation. () Ramp ×   SoftStart If an over current condition occurs, the outputs are dis- 2   T ≅ SoftStart abled and after a soft start delay time of about 100µs, the   R Internal _ SlopeComp   + 1 softstart sequence mentioned above is repeated.   R CS _ to _ GND   If longer soft start durations are required, the simple exter- nal circuit shown below can be implemented. REF VCC C26 2.2u,16V REF R37 R27 U4 R28 1k 15k 5 6 10 REF GND 6 4 7 FB OUTB C40 NA 3 8 CS OUTA 5 2 9 56.2K RC VCC C31 C33 MOCD207 1 10 SYNC LUVLO 200p 0.1u,25V Csoft start SC4808 SYNC 56.2k 10k Vin R23 R33 Approximate soft start duration can be calculated as be- low: T ≅ C × R37 SoftStart SoftStart  2005 Semtech Corp. 21 www.semtech.com SC4808A/B POWER MANAGEMENT Application Information (Cont.) LAYOUT GUIDELINES Careful attention to layout requirements are necessary for and secondary ground planes should be used. The same successful implementation of the SC4808 PWM control- precautions should be followed for the primary GND plane ler. as mentioned in item 5 mentioned above. For the second- High current switching is present in the application and ary GND plane, the GND plane method mentioned in item their effect on ground plane voltage differentials must be 4 should be followed. understood and minimized. 8) All the noise sensitive components such as LUVLO re- 1). The high power parts of the circuit should be laid out sistive divider, reference by pass capacitor, Vcc bypass ca- first. A ground plane should be used, the number and po- pacitor, current sensing circuitry, feedback circuitry, and sition of ground plane interruptions should be such as to the oscillator resistor/capacitor network should be con- not unnecessarily compromise ground plane integrity. Iso- nected as close as possible to the SC4808. The GND re- lated or semi-isolated areas of the ground plane may be turn should be connected to the quiet SC4808 GND plane. deliberately introduced to constrain ground currents to 9) The connection from the OUTA and OUTB of the SC4808 particular areas, such as the input capacitor and FET should be minimized to avoid any stray inductance. If the ground. layout can not be optimized due to constraints, a small 2). In the loop formed by the Input Capacitor(s) (Cin), the Schottky diode may be connected from the OUTA/B pins FET must be kept as small as possible. This loop contains to the ground directly at the IC. This will clamp excessive all the high current, fast transition switching. Connections negative voltages at the IC. If drivers are used, the Schottky should be as wide and as short as possible to minimize diodes should be connected directly at the IC from the loop inductance. Minimizing this loop area will a) reduce output of the driver to the driver ground (See page 9). EMI, b) lower ground injection currents, resulting in electri- 10) If the SYNC function is not used, the SYNC pin should cally “cleaner” grounds for the rest of the system and c) be grounded at the SC4808 GND to avoid noise pick up. minimize source ringing, resulting in more reliable gate switching signals. 3). The connection between FETs and the Transformer should be a wide trace or copper region. It should be as short as practical. Since this connection has fast voltage transitions, keeping this connection short will minimize EMI. 4) The Output Capacitor(s) (Cout) should be located as close to the load as possible. Fast transient load currents are supplied by Cout only, and connections between Cout and the load must be short, wide copper areas to minimize in- ductance and resistance. 5) The SC4808 is best placed over a quiet ground plane area. Avoid pulse currents in the Cin FET loop flowing in this area. GND should be returned to the ground plane close to the package and close to the ground side of (one of) the VCC supply capacitor(s). Under no circumstances should GND be returned to a ground inside the Cin, Q1, Q2 loop. Avoid making a star connection between the quiet GND planes that the SC4808 will be connected to and the noisy high current GND planes connected to the FETs. 6) The feed back connection between the error amplifier and the FB pin should be kept as short as possible The GND connections should be connected to the quiet GND used for the SC4808. 7) If an Opto isolator is used for isolation, quiet primary  2005 Semtech Corp. 22 www.semtech.com SC4808A/B POWER MANAGEMENT Gain & Phase Margin 50 225 Gain Phase (deg) 180 Gain 40 135 30 Phase 90 20 45 10 0 -45 0 -90 -10 -135 -20 -180 -30 -225 10 100 1000 10000 100000 Freq (Hz) Typical SC4808 Push Pull Converter Gain/Phase plot at Vin = 36V, Vout = 3.3V, Iout = 10A, Fosc = 650kHz  2005 Semtech Corp. 23 www.semtech.com Gain (dB) Phase (deg) SC4808A/B POWER MANAGEMENT Gain & Phase Margin (Cont.) 50 225 Gain Phase (deg) 180 Gain 40 135 30 Phase 90 20 45 10 0 -45 0 -90 -10 -135 -20 -180 -30 -225 10 100 1000 10000 100000 Freq (Hz) Typical SC4808 Push Pull Converter Gain/Phase plot at Vin = 48V, Vout = 3.3V, Iout = 10A, Fosc = 650kHz  2005 Semtech Corp. 24 www.semtech.com Gain (dB) Phase (deg) SC4808A/B POWER MANAGEMENT Gain & Phase Margin (Cont.) 50 225 Gain Phase (deg) 180 Gain 40 135 30 Phase 90 20 45 10 0 -45 0 -90 -10 -135 -20 -180 -30 -225 10 100 1000 10000 100000 Freq (Hz) Typical SC4808 Push Pull Converter Gain/Phase plot at Vin = 72V, Vout = 3.3V, Iout = 10A, Fosc = 650kHz  2005 Semtech Corp. 25 www.semtech.com Gain (dB) Phase (deg) SC4808A/B POWER MANAGEMENT Typical Step Load Vout 500mV/Div Iout 5A/Div 100us/Div Cout = 6X22uF (132uF) Ceramic Typical SC4808 Push Pull Converter Step Load plot at Vin = 48V, Vout = 3.3V, Step = 37% to 75% Iout, Fosc = 650kHz  2005 Semtech Corp. 26 www.semtech.com CON1 9 Vout+ PA0500 MBRB2535CTL 1 2 10 4 R1 3 8 Murata GRM32DR60J226KA01 Sense+ PG0006.102T 10 R2 6T 1T 0 T2 D1 GRM55DR72E105KW01 4 L1 GRM55DR72E105KW01 P8208T 2.2n C1 9 1 2 C2 8 7 3 C4 C5 C6 C7 C8 C9 CON2 R3 R4 10 R5 C10 0.9uH 250 6T 1T MBRB2535CTL 7 Trim 1 1 22u,6.3V 22u,6.3V 22u,6.3V 22u,6.3V 22u,6.3V 22u,6.3V 0.1u 0.1u 20k 2.2n C3 Vin+ FZT853 5 8 4 1 3 C11 C12 Q1 C C13 R6 B TBD 0 D2 R7 4T 6 1u,100V 1u,100V VCC 1u,100V 3 3 16.2 R31 N = 100 Sense- 2 R8 SUD19N20-90 SUD19N20-90 6 ON/OFF E 0 C A 4 3 T1 1 3 1 1 VCC = 15V 0 D3 1N5819HW M1 M2 D4 1N5819HW 1N5819HW U7 CBRHD-02 5 2 2 Vout- 4 R9 R10 Vin- 2.2 2.2 C14 C15 D5 D6 ZM4743A 5output_half_brick .1u,16V 10u,16V 1 2 3input_half_brick L2 LQH43MN102K011 1 2 GRM32DR61C106KA01 VCC C16 R11 G_B G_A TBD 10u,16V GRM32DR61C106KA01 G_B VCC SC1301A 3 5 U2 CMOSH-3 R12 56.2k C17 C18 R13 10k REF VCC 0.1u D7 22nF LS4448 J1 J2 1 4 D8 C19 R15 2.2u,16V D9 R14 15 0 2 CMOSH-3 R16 R17 U1 R18 T3 D10 D11 1k 15k 5 6 10 1 6 REF GND CMOSH-3 CMOSH-3 4 7 1u,16V FB OUTB C20 Sync Drive Supply 3 8 CS OUTA G_A VCC 3 4 C21 2 9 SC1301A 0 D13 D12 RC VCC C22 PE-68386 82p R19 1 10 3 5 U3 SYNC LUVLO CMOSH-3 CMOSH-3 82p CMOSH-3 Sync Drive Supply C23 C24 0.1u,25V SC4808 0.1u D14 0 JP1 J3 1 4 R20 SYNC 2.2k D15 10k R21 1 R22 2 CMOSH-3 5 37.4k 10nF C25 4 U6 C26 C27 0.1u 22n U4 8 1 SC4431 C34 REF R23 .1uF REF 18.2k 7 2 Vref R24 R32 1k 56.2k 2 6 3 C28 FMMT718 NA Sync Drive Supply Q2 5 4 100pF C29 C35 2.2uF 16V R26 R25 MOCD207 C30 R27 11.5k 2.2k 1nF 15k 1 R28 5 25.5k C31 470pF 4 C32 C33 R29 0.1u 22n U5 100 SC4431 R30 15k C Vref D16 1N5819HW 2 A Note: For output power > 30W, adequate air flow should be provided to avoid over dissipation. SEMTECH CORPORATION Title SC4808 Push Pull 3.3V 50W non Synchronous Size Document Number Rev SC4808EVB__non_sync 1.1 Date: Monday, October 07, 2002 Sheet of 11 SC4808A/B POWER MANAGEMENT Evaluation Board Schematics  2005 Semtech Corp. 27 www.semtech.com SC4808A/B POWER MANAGEMENT Evaluation Board Bill of Materials SC4808 Push Pull 3.3V 50W non Synchronous SC4808EVB__non_sync Revision: 1.1 Bill Of Materials October 7,2002 13:35:18 Item Quantity Reference Part Manufacturer # Foot Print 1 1 CON1 5output_half_brick CON\5OUTPUT_HALF_BRICK 2 1 CON2 3input_half_brick CON\3INPUT_HALF_BRICK 3 2 C3,C1 2.2n SM/C_1206 4 6 C2,C10,C17,C24,C26,C32 0.1u SM/C_0805 5 6 C4,C5,C6,C7,C8,C9 22u,6.3V GRM32DR60J226KA01 SM/C_1210_GRM 6 3 C11,C12,C13 1u,100V GRM55DR72E105KW01 SM/C_2220 7 1 C14 .1u,16V SM/C_0805 8 2 C15,C16 10u,16V GRM32DR61C106KA01 SM/C_1210_GRM 9 1 C18 22nF SM/C_1206 10 1 C19 2.2u,16V SM/C_1206 11 1 C20 1u,16V GRM32RR71H105KA011 SM/C_1210_GRM 12 2 C22,C21 82p SM/C_0805 13 1 C23 0.1u,25V SM/C_1206 14 1 C25 10nF SM/C_0805 15 2 C27,C33 22n SM/C_0805 16 1 C28 NA SM/C_0805 17 1 C29 100pF SM/C_0805 18 1 C30 1nF SM/C_0805 19 1 C31 470pF SM/C_0805 20 1 C34 .1uF SM/C_0805 21 1 C35 2.2uF 16V SM/C_0805 22 2 D2,D1 MBRB2535CTL DIODE_D2PAK 23 4 D3,D5,D6,D16 1N5819HW SOD123 24 1 D4 ZM4743A SMB/DO214 25 8 D7,D9,D10,D11,D12,D13, CMOSH-3 CMOSH-3 (Central Semiconductor) SOD523 D14,D15 26 1 D8 LS4448 SM/DO213AC 27 1 JP1 short VIA\2P 28 1 J1 REF ED5052 29 1 J2 Vcc ED5052 30 1 J3 SYNC ED5052 31 1 L1 0.9uH PG0006 32 1 L2 LQH43MN102K011 LQH43MN102K01L SDIP0302 33 2 M1,M2 SUD19N20-90 SUD19N20-90 DPAKFET 34 1 Q1 FZT853 SM/SOT223_BCEC 35 1 Q2 FMMT718 36 4 R1,R7,R15,R19 0 SM/R_0805 37 2 R5,R2 10 SM/R_1206 38 1 R3 20k SM/R_1206 39 1 R4 250 SM/R_1210_MCR 40 2 R6,R11 TBD SM/R_0805 41 1 R8 0 SM/R_1206 42 2 R9,R10 2.2 SM/R_0805 43 1 R12 56.2k SM/R_1206 44 1 R13 10k SM/R_0805 45 1 R14 15 SM/R_0805 46 2 R16,R24 1k SM/R_0805 47 3 R17,R27,R30 15k SM/R_0805 48 1 R18 10 SM/R_0805 49 2 R26,R20 2.2k SM/R_0805 50 1 R21 10k SM/R_1206 51 1 R22 37.4k SM/R_0805 52 1 R23 18.2k SM/R_0805 53 1 R25 11.5k SM/R_0805 54 1 R28 25.5k SM/R_0805 55 1 R29 100 SM/R_0805 56 1 R31 16.2 SM/R_1206 57 1 R32 56.2k SM/R_0805 58 1 T1 PA0500 PA0500 59 1 T2 P8208T P8208T 60 1 T3 PE-68386 PE-68386 61 1 U1 SC4808 MSOP10 62 2 U2,U3 SC1301A SOT23_5PIN 63 2 U4,U5 SC4431 SOT23_5PIN 64 1 U6 MOCD207 SO-8 65 1 U7 CBRHD-02 CBRHD-02  2005 Semtech Corp. 28 www.semtech.com SC4808A/B POWER MANAGEMENT Evaluation Board Gerber Plots Board Layout Assembly Top Board Layout Assembly Bottom Board Layout Top Board Layout Bottom  2005 Semtech Corp. 29 www.semtech.com SC4808A/B POWER MANAGEMENT Evaluation Board Gerber Plots Board Layout INNER1 Board Layout INNER2  2005 Semtech Corp. 30 www.semtech.com SC4808A/B POWER MANAGEMENT Outline Drawing - MSOP-10 DIMENSIONS e INCHES MILLIMETERS DIM A MIN NOM MAX MIN NOM MAX D - - - - A .043 1.10 N - - A1 .000 .006 0.00 0.15 - - A2 .030 .037 0.75 0.95 - - b .007 .011 0.17 0.27 2X E/2 c - - .003 .009 0.08 0.23 .114 .118 .122 2.90 3.00 3.10 D E1 E E1 .114 .118 .122 2.90 3.00 3.10 PIN 1 E .193 BSC 4.90 BSC INDICATOR e .020 BSC 0.50 BSC L .016 .024 .032 0.40 0.60 0.80 ccc C 12 (.037) (.95) L1 N 10 10 2X N/2 TIPS B - - 01 0° 8° 0° 8° aaa .004 0.10 bbb .003 0.08 ccc .010 0.25 D aaa C H A2 A SEATING PLANE c GAGE A1 C PLANE bxN bbb C A-B D 0.25 L 01 (L1) DETAIL A SEE DETAIL A SIDE VIEW NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. DATUMS AND TO BE DETERMINED AT DATUM PLANE -A- -B- -H- DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS 3. OR GATE BURRS. 4. REFERENCE JEDEC STD MO-187, VARIATION BA. Land Pattern - MSOP-10 X DIMENSIONS DIM INCHES MILLIMETERS (.161) (4.10) C (C) G .098 2.50 G Z P .020 0.50 X .011 0.30 Y .063 1.60 Z .224 5.70 Y P NOTES: 1. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. Contact Information Semtech Corporation Power Management Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805)498-2111 FAX (805)498-3804  2005 Semtech Corp. 31 www.semtech.com

Frequently asked questions

What makes Elite.Parts unique?

chervon down
At GID Industrial (Elite.Parts' parent company), we specialize in procuring industrial parts. We know where to find the rare and obsolete equipment that our customers need in order to get back to business. There are other companies who claim to do what we do, but we're confident that our commitment to quality and value is unparalleled in our field.

What kind of warranty will the SC4808B have?

chervon down
Warranties differ by part and by which suppliers we use to procure it for you. Sometimes, a part will be sold as-is and without a warranty. Our specialty, single board computers, tend to receive a one-year warranty.

Which carriers does Elite.Parts work with?

chervon down
Elite.Parts can ship via FedEx, UPS, DHL, and USPS. We have accounts with each of them and generally ship using one of those, but we can also ship using your account if you would prefer. However, we can use other carriers if it will be more convenient for you.

Will Elite.Parts sell to me even though I live outside the USA?

chervon down
Absolutely! We are happy to serve customers regardless of location. We work with international clients all the time, and we are familiar with shipping to destinations all across the globe.

I have a preferred payment method. Will Elite.Parts accept it?

chervon down
All major credit cards are accepted: Visa, MasterCard, Discover, and American Express. We will also accept payment made with wire transfer or PayPal. Checks will only be accepted from customers in the USA. Terms may available for larger orders, upon approval.

Why buy from GID?

quality

Quality

We are industry veterans who take pride in our work

protection

Protection

Avoid the dangers of risky trading in the gray market

access

Access

Our network of suppliers is ready and at your disposal

savings

Savings

Maintain legacy systems to prevent costly downtime

speed

Speed

Time is of the essence, and we are respectful of yours

What they say about us

FANTASTIC RESOURCE

star star star star star

One of our top priorities is maintaining our business with precision, and we are constantly looking for affiliates that can help us achieve our goal. With the aid of GID Industrial, our obsolete product management has never been more efficient. They have been a great resource to our company, and have quickly become a go-to supplier on our list!

Bucher Emhart Glass

EXCELLENT SERVICE

star star star star star

With our strict fundamentals and high expectations, we were surprised when we came across GID Industrial and their competitive pricing. When we approached them with our issue, they were incredibly confident in being able to provide us with a seamless solution at the best price for us. GID Industrial quickly understood our needs and provided us with excellent service, as well as fully tested product to ensure what we received would be the right fit for our company.

Fuji

HARD TO FIND A BETTER PROVIDER

star star star star star

Our company provides services to aid in the manufacture of technological products, such as semiconductors and flat panel displays, and often searching for distributors of obsolete product we require can waste time and money. Finding GID Industrial proved to be a great asset to our company, with cost effective solutions and superior knowledge on all of their materials, it’d be hard to find a better provider of obsolete or hard to find products.

Applied Materials

CONSISTENTLY DELIVERS QUALITY SOLUTIONS

star star star star star

Over the years, the equipment used in our company becomes discontinued, but they’re still of great use to us and our customers. Once these products are no longer available through the manufacturer, finding a reliable, quick supplier is a necessity, and luckily for us, GID Industrial has provided the most trustworthy, quality solutions to our obsolete component needs.

Nidec Vamco

TERRIFIC RESOURCE

star star star star star

This company has been a terrific help to us (I work for Trican Well Service) in sourcing the Micron Ram Memory we needed for our Siemens computers. Great service! And great pricing! I know when the product is shipping and when it will arrive, all the way through the ordering process.

Trican Well Service

GO TO SOURCE

star star star star star

When I can't find an obsolete part, I first call GID and they'll come up with my parts every time. Great customer service and follow up as well. Scott emails me from time to time to touch base and see if we're having trouble finding something.....which is often with our 25 yr old equipment.

ConAgra Foods

Related Products

product

Semtech SC1151CS Programmable DC/DC Controller For Advanced Microprocessors

product

Semtech SC1175 Low Power Dual Synchronous DC/DC Controller With Current-Sharing Circuitry

product

Semtech SC1176 Dual Synchronous Voltage-Mode Controller with Current-Sharing Circuitry

product

Semtech SC1176A Dual Synchronous Voltage-Mode Controller with Current-Sharing Circuitry

product

Semtech SC1185 Programmable Synchronous DC/DC Converter, Dual Low Dropout Regulator Controller

product

Semtech SC1211STR Driver. MOSFET | 3.5A | 2-Out | Hi/Lo Side | Inv/Non-Inv | 8-Pin