SEMTECH SC194B

SC194B Selectable 3.6V/3.3V/3.0V/2.5V 1A Synchronous Buck Converter POWER MANAGEMENT Description Features The SC194B is a synchronous step-down converter with ‹ Up to 95% efŢ ciency integrated power devices. Four selectable output voltages ‹ PSAVE operation to maximize efŢ ciency suitable for portable device interface, memory function ‹ Output current — 1A blocks, and 5V to 3.3V voltage conversion are available. ‹ Input range — 2.7V to 5.5V ‹ Four selectable output voltages Automatic selection of Power Save Mode (PSAVE) is ‹ Quiescent current — 17μA in PSAVE supported which enhances efŢ ciency. A 100% duty cycle ‹ Dynamic voltage positioning capability mode allows operation for input voltages close to the ‹ Fixed 1MHz frequency or 750kHz to 1.25MHz syn- required output voltage. chronized operation ‹ Current mode operation for excellent line and load The need for external components is minimized by transient response providing internal feedback compensation, and allowing ‹ 100% duty cycle in dropout selection of the required output voltage by hard wiring VID ‹ Soft-start code inputs. The maximum current rating of the internal ‹ Over-temperature and short-circuit protection MOSFET switches allows a DC output current of 1A. ‹ Lead-free package — 3mm x 3mm MLPD The switching frequency is nominally set to 1MHz, allowing Applications the use of small inductors and capacitors. A ţ exible ‹ PDA clocking scheme is used that allows synchronization to an ‹ Pocket PC and Smart Phones external oscillator or control by the internal oscillator. ‹ USB Powered Modems ‹ CPUs and DSPs The device can operate in either forced PWM mode or ‹ PC Cards and Notebooks in PSAVE mode. If PSAVE mode is enabled the part will ‹ xDSL Applications automatically enter PSAVE at light loads to maintain ‹ Standard 5-V to 3.3-V Conversion maximum efŢ ciency across the full load range. For noise sensitive applications, PSAVE mode can be disabled by synchronizing to an external oscillator, or pulling the SYNC/ PWM pin high. Shutdown turns off all the control circuitry to achieve a typical shutdown current of 0.1μA. Typical Application Circuit L1 SC194B V OUT VIN LX 3.3V V IN EN 4.7μH 1A 3.6V to 5.5V SYNC/PWM VOUT C C IN OUT VID0 VID1 PGND 10μF 22μF MODE GND 1 August 24, 2006 www.semtech.com SC194B POWER MANAGEMENT Absolute Maximum Ratings Exceeding the speciŢ cations below may result in permanent damage to the device or device malfunction. Operation outside of the parameters speciŢ ed in the Electrical Characteristics section is not recommended. Parameter Symbol Maximum Units Input Supply Voltage V -0.3 to 7 V IN Logic Inputs V -0.3 to V +0.3, 7V Max V N IN (SYNC/PWM, EN, MODE, VID0, VID1) Output Voltage V -0.3 to V +0.3, 7V Max V OUT IN LX Voltage V -1 to V +1, 7V Max V LX IN (1) Thermal Impedance Junction to Ambient θ 40 °C/W JA VOUT Short-Circuit to GND t Continuous s SC Operating Ambient Temperature Range T -40 to +85 °C A Storage Temperature T -60 to +160 °C S Junction Temperature T -40 to +150 °C JC Peak IR Reţ ow Temperature T 260 °C P (2) ESD Protection Level V 2kV ESD Note: (1) Calculated from package in still air, mounted to 3” x 4.5”, 4 layer FR4 PCB with thermal vias under the exposed pad per JESD51 standards. (2) Tested according to JEDEC standard JESD22-A114-B. Electrical Characteristics Unless otherwise noted: V = 5V ,V = 3.3V, EN = V , SYNC/PWM = V , MODE = V , T = -40 to 85°C. Typical values are at T =25°C. IN OUT IN IN IN A A Parameter Symbol Conditions Min Typ Max Units Input Voltage Range V V > V + dropout 2.7 5.5 V IN IN OUT I = 0.5A, T = 25°C OUT A VOUT Accuracy V ±1% OUT V = 2.5/3.0/3.3/3.6V OUT VOUT Temperature Accuracy V I = 0.5A, T =-40°C to 85°C ±0.3 ±0.7 % OUT(T) OUT A V = 2.7V to 5.5V, V = 2.5V, IN OUT Line Regulation V ±0.4 ±0.65 % OUT LINE I = 0.5A, T =-40°C to 85°C OUT A Load Regulation (PWM) V I = 0A to 1A ±0.3 ±0.65 % OUT LOAD OUT +1.3 +1.6 PSAVE Regulation V SYNC/PWM = GND, C =22μF % OUT PSAVE OUT -0.3 -0.6 P-Channel On Resistance R I = 100mA, V =3.6V 0.275 Ω DSP LX IN N-Channel On Resistance R I = 100mA, V =3.6V 0.165 Ω DSN LX IN Start-Up Time T 5ms START P-Channel Current Limit I V = 2.7V to 5.5V 1.33 1.9 2.47 A LIM(P) IN 2 © 2006 Semtech Corp. www.semtech.com SC194B POWER MANAGEMENT Electrical Characteristics (Cont.) Parameter Symbol Conditions Min Typ Max Units SYNC/PWM = GND, I = 0A, OUT Quiescent Current I 17 28 μA Q V = 1.04 x V , V = 3.6V OUT OUT(Programmed) IN Shutdown Current I EN = GND, LX = OPEN, V = 3.6V 0.1 1 μA SD IN LX Leakage Current PMOS I V = 3.6V, LX = GND, EN = GND 0.1 2 μA LXP IN LX Leakage Current NMOS I V = 3.6V, LX = 3.6V, EN = GND -2 0.1 μA LXN IN Oscillator Frequency f V = 3.6V 0.85 1.0 1.15 MHz OSC IN SYNC Frequency (upper) f V = 3.6V 1.25 MHz SYNCU IN SYNC Frequency (lower) f V = 3.6V 750 kHz SYNCL IN UVLO Threshold (upper) V 2.38 2.52 2.65 V UVL UVLO Hysteresis V 100 mV UVLHYS Thermal Shutdown T 145 °C SD Thermal Shutdown Hysteresis T 10 °C SD-HYS Logic Input High V EN, SYNC/PWM, VID0, VID1, MODE 1.6 V IH Logic Input Low V EN, SYNC/PWM, VID0, VID1, MODE 0.6 V IL Logic Input Current High I EN, SYNC/PWM, VID0, VID1, MODE -2 0.1 2 μA IH Logic Input Current Low I EN, SYNC/PWM, VID0, VID1, MODE -2 0.1 2 μA IL 3 © 2006 Semtech Corp. www.semtech.com SC194B POWER MANAGEMENT Pin ConŢ guration Ordering Information DEVICE PACKAGE (1)(2) SC194BMLTRT MLP 3x3-10 Evaluation Board SC194BEVB Ordering Information Notes: VIN 1 10 LX 1) Lead-free packaging only. This product is fully WEEE and RoHS compliant. 2) Available in tape and reel only. A reel contains 3000 devices. TOP VIEW MODE 2 9 PGND SYNC/PWM 3 8 GND EN 4 7 VID1 T Programmable Output Voltage 56 VID0 VOUT VID1 VID0 SC194B V OUT 0 0 2.5V MLP10: 3X3 10 LEAD 0 1 3.0V 1 0 3.3V 1 1 3.6V Marking Information 194B yyww xxxx yy = two digit year of manufacture ww = two digit week of manufacture xxxx = lot number 4 © 2006 Semtech Corp. www.semtech.com SC194B POWER MANAGEMENT Pin Descriptions Pin # Pin Name Pin Function 1 VIN Input power supply voltage 2 MODE MODE select pin where MODE = V to select 100% duty cycle function and MODE = GND to IN disable Oscillator synchronization input — Tie to V for forced PWM mode or GND to allow the part to IN 3 SYNC/PWM enter PSAVE mode at light loads. Apply an external clock signal for frequency synchronization. Enable digital input — A high input enables the SC194B, a low disables and reduces quiescent 4EN current to less than 1μA. In shutdown, LX becomes high impedance. 5 VOUT Regulated output voltage and feedback for SC194B Logic level bit 0 is used in conjunction with VID1 to set the output voltage. Connect high or low 6 VID0 as required to select the desired output voltage. If not connected, the output voltage will be indeterminate. Logic level bit 1 is used in conjunction with VID0 to set the output voltage. Connect high or low 7 VID1 as required to select the desired output voltage. If not connected, the output voltage will be indeterminate. 8 GND Ground 9 PGND Power Ground 10 LX Inductor connection to the switching FETs THERMAL Pad is for heatsinking purposes — not connected internally. Connect exposed pad to ground T PAD plane using multiple vias. 5 © 2006 Semtech Corp. www.semtech.com SC194B POWER MANAGEMENT Block Diagram Plimit Amp VIN 1 Current Amp EN 4 OSC & Slope SYNC/ 3 Generator PWM Control 10 LX Logic PWM Comp 500mV Ref Error Amp PSAVE Comp Nlimit Amp 9 PGND 2 MODE 7 VID1 Voltage GND Select 8 VID0 6 5 VOUT 6 © 2006 Semtech Corp. www.semtech.com SC194B POWER MANAGEMENT Applications Information SC194B Detailed Description • Over-voltage protection The SC194B is a synchronous step-down Pulse Width • Soft-start Modulated (PWM), DC-DC converter utilizing a 1MHz Ţ xed-frequency current mode architecture. The device is Thermal Shutdown designed to operate in Ţ xed-frequency PWM mode across The device has a thermal shutdown feature to protect the the full load range and can enter power save mode (PSAVE) SC194B if the junction temperature exceeds 145°C. In utilizing Pulse Frequency Modulation (PFM) at light loads thermal shutdown the on-chip power devices are disabled, to maximize efŢ ciency. tri-stating the LX output. Switching will resume when the temperature drops by 10°C. During this time if the output Operation voltage decreases by more than 60% of its programmed During normal operation the PMOS MOSFET is activated value, a soft-start will be invoked. on each rising edge of the internal oscillator. Current feedback for the switching regulator is through the Current Limit PMOS current path, and it is ampliŢ ed and summed with The PMOS and NMOS power devices of the buck switcher the internal slope compensation network. The voltage stage are protected by current limit functions. In the case of feedback loop uses an internal feedback divider. The on- a short to ground on the output, the part enters frequency time is determined by comparing the summed current foldback mode that causes the switching frequency to feedback and the output of the error ampliŢ er. The period divide by a factor determined by the output voltage. This is set by the onboard oscillator or by an external clock prevents the inductor current from "stair-casing". attached to the SYNC/PWM pin. Over-Voltage Protection The SC194B has an internal synchronous NMOS rectiŢ er Over-voltage protection is provided on the SC194B. In the and does not require a Schottky diode on the LX pin. event of an over-voltage on the output in switcher mode, the PWM drive is disabled, tri-stating the LX output. The Programmable Output Voltage part will not resume switching until the output voltage has The SC194B has four pre-determined output voltage fallen below 2% of the regulation voltage. values which can be individually selected by the correct programming of the VID0 and VID1 pins (see Soft-Start Programmable Output Voltage table on Page 4). This The soft-start mode is enabled after every shutdown cycle eliminates the need for external programming resistors to limit in-rush current. In conjunction with the frequency saving PCB area and inventory. The VID pins can be foldback, this controls the maximum current during start- statically tied to GND or VIN for Ţ xed output conŢ gurations up. The PMOS current limit is stepped up through seven or they may be driven by a microprocessor enabling soft-start levels to the full value by a timer driven from the possibility of dynamic voltage adjustment for host the internal oscillator. During soft-start, the switching equipment "sleep" states. frequency is stepped by 1/8, 1/4, and 1/2 of the internal oscillator frequency up to the full value, under control of Oscillator Synchronization Opotions three output voltage thresholds. As soon as the output The SC194B is designed to operate in continuous voltage is within 2% of the regulation voltage, soft-start conduction, Ţ xed-frequency mode. When the SYNC/PWM mode is disabled. pin is tied high the part runs in PWM mode using the internal oscillator. The part can be synchronized to an Power Save Mode Operation external clock by driving a clock signal into the SYNC/ The PSAVE mode may be selected by tying the SYNC/PWM PWM pin. The part synchronizes to the rising edge of the pin to GND. Selecting PSAVE mode will enable the SC194B clock. to automatically activate/deactivate operation at light loads maximizing efŢ ciency across the full load range. The Protection Features SC194B automatically detects the load current at which The SC194B provides the following protection features: it should enter PSAVE mode. The SC194B is optimized to • Thermal shutdown track maximum efŢ ciency with respect to V . IN • Current limit 7 © 2006 Semtech Corp. www.semtech.com SC194B POWER MANAGEMENT Applications Information (Cont.) In PSAVE mode V is driven from a lower level to an 100% Duty Cycle Operation OUT upper level by a switching burst. Once the upper level has The 100% duty cycle mode may be selected by connecting been reached the switching is stopped and the quiescent the MODE pin high. This will allow the SC194B to maintain current is reduced. V falls from the upper to lower levels output regulation under low input voltage/high output OUT in this low current state as the load current discharges voltage conditions. the output capacitor. The burst-to-off period in PSAVE will decrease as the load current reduces. In 100% duty cycle operation, as the input supply drops toward the output voltage, the PMOS on-time increases The PSAVE switching burst frequency is controlled so linearly above the maximum value in Ţ xed-frequency that the inductor current ripple is similar to that in PWM operation until the PMOS is active continuously. Once mode. the PMOS is switched on continuously, the output voltage tracks the input voltage minus the voltage drop across The SC194B automatically detects when to exit PSAVE the PMOS power device and inductor according to the mode by monitoring V . For the SC194B to exit PSAVE following relationship: OUT mode, the load must be increased, causing V to OUT decrease until the power save exit threshold is reached. V V V V II uu (R (R  R R ) ) OUT OUT OUT OUT DSP DSP IND IND IN IN PSAVE levels are set high to minimize the undershoot when exiting PSAVE. The lower PSAVE comparator level where, is set +0.7% above V , and the upper comparator level V = Output voltage OUT OUT at +1.5% above V , with the exit threshold at -2% below V = Input voltage OUT IN V . I = Output current OUT OUT R = PMOS switch ON resistance DSP If PSAVE operation is required then a 22μF output R = Series resistance of the inductor IND capacitor must be used. Inductor Selection Power Save Operation The SC194B is designed for use with a 4.7μH inductor. The magnitude of the inductor current ripple is dependent Higher Load Applied BURST OFF on the inductor value and can be determined by the 1.5% following equation: 0.7% PSAVE Mode at Light Load PWM Mode at Medium/ § · V V High Load OUT OUT 'I ¨1 ¸ VOUT L ¨ ¸ Lu f V osc © IN ¹ -2% This equation demonstrates the relationship between input voltage, output voltage, and inductor ripple Inductor Current current. The inductor should have a low DCR to minimize the 0 A conduction losses and maximize efŢ ciency. As a Time minimum requirement, the DC current rating of the inductor should be equal to the maximum load current plus half of the inductor current ripple as shown by the following equation: 'I L I IOUT(MAX)  L(PK) 2 8 © 2006 Semtech Corp. www.semtech.com SC194B POWER MANAGEMENT Applications Information (Cont.) Final inductor selection will depend on various design Capacitors with X7R or X5R ceramic dielectric are considerations such as efŢ ciency, EMI, size and cost. strongly recommended for their low ESR and superior Table 1 lists the manufacturers of practical inductor temperature and voltage characteristics. Y5V capacitors options. should not be used as their temperature coefŢ cients make them unsuitable for this application. Table 2 lists Table 1 — Recommended Inductors the manufacturers of recommended capacitor options. Saturation Dimensions Tolerance Value DCR Manufacturer/Part No. Current LxWxH (+%) (μH) (Ω) Table 2 — Recommended Capacitors (A) (mm) Rated BI Technologies Value Temperature 4.7 0.072 1.32 20 4.7 × 4.7 ×3.0 Manufacturer/Part No. Voltage Case Size HM66304R7 (μF) Characteristic (VDC) Coilcraft 4.7 0.09 1.5 20 6.6 × 4.5 ×3.0 Murata D01608C-472ML 22 6.3 X5R 0805 GRM21BR60J226ME39L TDK 4.7 0.101 1.07 30 4.3 × 4.0 ×1.8 Murata VLCF4018T- 4R7N1R0-2 10 6.3 X5R 0603 GRM188R60J106MKE19 TDK 10 6.3 X5R 0603 C2012X5R0J106K C Selection IN Note: Where PSAVE operation is required 22μF must be used for C . OUT The source input current to a buck converter is non- continuous. To prevent large input voltage ripple a low ESR ceramic capacitor is required. A minimum value of 10μF should be used for sufŢ cient input voltage Ţ ltering and a 22μF should be used for improved input voltage Ţ ltering. C Selection OUT The internal compensation is designed to work with a certain output Ţ lter corner frequency deŢ ned by the equation: 1 1 ff C C 2 2SS L LuuC C OUT OUT This single pole Ţ lter is designed to operate with a minimum output capacitor value of 10μF. Larger output capacitor values will improve transient performance. If PSAVE operation is required the minimum capacitor value is 22μF. Output voltage ripple is a combination of the voltage ripple from the inductor current charging and discharging the output capacitor and the voltage created from the inductor current ripple through the output capacitor ESR. Selecting an output capacitor with a low ESR will reduce the output voltage ripple component, as can be seen in the following equation: ǻǻV V ǻǻII uuESR ESR OUT(ESR) OUT(ESR) L(ripple) L(ripple) COUT COUT 9 © 2006 Semtech Corp. www.semtech.com SC194B POWER MANAGEMENT Applications Information (Cont.) PCB Layout Considerations Poor layout can degrade the performance of the DC-DC 2. Route the output voltage feedback path away from the converter and can contribute to EMI problems, ground inductor and LX node to minimize noise and magnetic interference. bounce and resistive voltage losses. Poor regulation and 3. Maximize ground metal on the component side to instability can result. improve the return connection and thermal dissipation. A few simple design rules can be implemented to ensure Separation between the LX node and GND should be good layout: maintained to avoid coupling of switching noise to the ground plane. 4. Use a ground plane with several vias connecting to 1. Place the inductor and Ţ lter capacitors as close to the the component side ground to further reduce noise device as possible and use short wide traces between the power components. interference on sensitive circuit nodes. GND C IN V IN LX L OUT SC194B C OUT V OUT GND 10 © 2006 Semtech Corp. www.semtech.com SC194B POWER MANAGEMENT Typical Characteristics EfŢ ciency vs. Load Current V = 3.6V EfŢ ciency vs. Load Current V = 3.3V OUT OUT 100 100 V =3.9V, PSAVE V =3.9V, PSAVE IN IN 90 90 V =4.2V, PSAVE V =4.2V, PSAVE IN IN 80 80 V =5.0V, PSAVE V =5.0V, PSAVE IN IN 70 70 60 60 V =3.9V, PWM IN 50 50 V =5.0V, PWM V =3.9V, PWM IN IN V =5.0V, PWM IN 40 40 30 30 V =4.2V, PWM IN V =4.2V, PWM IN 20 20 10 10 0 0 0.0001 0.001 0.01 0.1 1 10 0.0001 0.001 0.01 0.1 1 10 IOUT (A) IOUT (A) EfŢ ciency vs. Load Current V = 3.0V EfŢ ciency vs. Load Current V = 2.5V OUT OUT 100 100 V =3.6V, PSAVE IN V =3.3V, PSAVE IN 90 90 80 80 V =4.2V, PSAVE IN V =4.2V, PSAVE IN 70 70 V =5.0V, PSAVE IN V =5.0V, PSAVE IN 60 60 V =5.0V, PWM IN 50 50 V =3.3V, PWM V =5.0V, PWM IN IN 40 40 V =3.6V, PWM IN 30 30 V =4.2V, PWM IN V =4.2V, PWM IN 20 20 10 10 0 0 0.0001 0.1 0.001 0.01 1 10 0.0001 0.001 0.01 0.1 1 10 I (A) IOUT (A) OUT EfŢ ciency vs. Input Voltage V = 3.3V PWM to PSAVE Hysteresis OUT 100 95 V =3.3V,PSAVE OUT PSAVE VOUT=3.3V,PWM 95 Entry 94 I OUT Decreasing 90 V =2.5V,PWM OUT 93 VOUT=2.5V,PSAVE 85 PSAVE EXIT 92 PWM IOUT Mode 80 Increasing 91 75 90 70 2.5 3 3.5 4 4.5 5 5.5 6 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 Vin (V) I (A) OUT I =500 mA(PWM)/50 mA(PSAVE) OUT 11 © 2006 Semtech Corp. www.semtech.com Efficiency (%) Efficiency (%) Eff (%) Efficiency (%) Efficiency (%) Efficiency (%) SC194B POWER MANAGEMENT Typical Characteristics V vs. V Load Regulation OUT IN Vin=5V, Vout=3.3V,PWM 3.6 3.292 VOUT=3.3V,PSAVE 3.4 3.29 3.2 VOUT=3.3V,PWM 3.288 3 3.286 2.8 3.284 V =2.5V,PSAVE OUT 2.6 3.282 V =2.5V,PWM 2.4 OUT 3.28 2.2 2 3.278 2.5 3 3.5 4 4.5 5 5.5 6 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 I (A) VIN (V) OUT I =500 mA(PWM)/50 mA(PSAVE) OUT Quiescent Current vs. Input Voltage V vs. Temperature OUT V = 3.3V OUT PSAVE Mode 3.35 22 21 3.34 T =85°C A 20 3.33 VIN=5.0V,PSAVE 19 3.32 18 3.31 17 TA=25°C 16 3.3 15 3.29 V =5.0V,PWM IN 14 T =-40°C A 3.28 13 3.27 12 4 55.5 2.5 3 3.5 4.5 6 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 V (V) IN T (°C) A Quiescent Current vs. Input Voltage N-Channel R vs. Input Voltage DSON PWM Mode 6 0.22 T =-40°C A 5.5 0.20 TA=85°C T =85°C A 5 0.18 TA=25°C T =25°C A 4.5 0.16 T =-40°C A 0.14 4 0.12 3.5 0.10 3 3.2 5.2 3.5 4 4.5 55.5 6 2.7 3.7 4.2 4.7 2.5 3 V (V) V (V) IN IN 12 © 2006 Semtech Corp. www.semtech.com V (V) OUT Quiescent Current (mA) V (V) OUT V (V) OUT R (Ω) DSON Quiescent Current (uA) SC194B POWER MANAGEMENT Typical Characteristics (Cont.) Switching Frequency vs. Temperature P-Channel R vs. Input Voltage DSON 0.40 1050 1040 0.35 1030 VIN=5.5V 1020 0.30 1010 T =85°C A V =2.7V IN 0.25 1000 T =25°C A 990 VIN=3.6V 0.20 TA=-40°C 980 970 0.15 960 0.10 950 2.7 3.2 4.2 -50 -30 -10 30 130 3.7 4.7 5.2 10 50 70 90 110 V (V) IN T (°C) J PSAVE Operation 100% Duty Cycle Mode V (50mV/div) V (50mV/div) OUT OUT I (200mA/div) LX I (500mA/div) LX V (5V/div) V (2V/div) LX LX Time (2μs/div) Time (400ns/div) Condition V =5V, l =50mA, V =3.3V Condition V = 3.8V, l = 1A, V = 3.3V IN OUT OUT IN OUT OUT PWM Operation PSAVE Start-UP V (2V/div) EN V (20mV/div) OUT V (2V/div) OUT I (500mA/div) LX I (200mA/div) IN V (5V/div) LX Time (400μs/div) Time (1μs/div) Condition V =5V, l =10mA, V =3.3V Condition V =5V, l =50mA, V =3.3V IN OUT OUT IN OUT OUT 13 © 2006 Semtech Corp. www.semtech.com R (Ω) DSON Switching Frequency (kHz) SC194B POWER MANAGEMENT Typical Characteristics (Cont.) PWM Start-Up Load Transient Response PWM V (2V/div) V (200mV/div) EN OUT V (2V/div) OUT I (500mA/div) OUT I (200mA/div) IN Time (400μs/div) Time (400μs/div) Condition V = 5V, l = 10mA, V = 3.3V Condition V = 5V, l = 1A to 100mA, V = 3.3V IN OUT OUT IN OUT OUT Load Transient Response PSAVE VID Code Change PWM V (200mV/div) V (200mV/div) OUT OUT I (500VmA/div)) V (2V/div) OUT VID1 Time (400μs/div) Time (400μs/div) Condition V = 5V, l = 1A, V = 2.5 to 3.3V Condition V = 5V, l = 1A to 100mA, V = 3.3V IN OUT OUT IN OUT OUT 14 © 2006 Semtech Corp. www.semtech.com SC194B POWER MANAGEMENT Applications Circuits V = 3.6V Forced PWM and 100% Duty Cycle OUT L1 SC194B V OUT VIN LX V IN 3.6V EN 4.7μH 3.9 to 5.5V 1A SYNC/PWM VOUT C C IN OUT VID0 VID1 PGND 10μF 10μF MODE GND Dynamic Voltage Positioning for Reduced System Dissipation in "Sleep" Modes V IN V OUT 2.7V to 5.5V 3.3V C IN norm L1 SC194B 10μF V OUT VIN LX 2.5V 4.7μH EN “sleep” SYNC/PWM VOUT C OUT VID0 VID1 PGND From uP 22μF MODE GND Sleep controller V = 2.5V with PSAVE and 100% Duty Cycle OUT L1 SC194B V OUT VIN LX V 2.5V IN EN 4.7μH 2.7V to 5.5V 1A SYNC/PWM VOUT C C IN OUT VID0 VID1 PGND 10μF 22μF MODE GND 15 © 2006 Semtech Corp. www.semtech.com SC194B POWER MANAGEMENT Outline Drawing - MLP-10 DIMENSIONS A E B INCHES MILLIMETERS DIM MIN NOM MAX MIN NOM MAX - - A .031 .039 0.80 1.00 - - A1 .000 .002 0.00 0.05 - - - - A2 (.008) (0.20) b .007 .009 .011 0.18 0.23 0.30 E C .074 .079 .083 1.87 2.02 2.12 D .042 .048 .052 1.06 1.21 1.31 PIN 1 E .114 .118 .122 2.90 3.00 3.10 INDICATOR e .020 BSC 0.50 BSC (LASER MARK) L .012 .016 .020 0.30 0.40 0.50 N 10 10 aaa .003 0.08 bbb .004 0.10 A SEATING PLANE aaa C A1 C A2 C 1 2 LxN D N e bxN bbb C A B NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS TERMINALS. 16 © 2006 Semtech Corp. www.semtech.com SC194B POWER MANAGEMENT Land Pattern - MLP-10 DIMENSIONS K DIM INCHES MILLIMETERS C (.112) (2.85) G .075 1.90 H H .055 1.40 G (C) Z K .087 2.20 P .020 0.50 X .012 0.30 Y Y .037 0.95 X Z .150 3.80 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 www.semtech.com 17 © 2006 Semtech Corp. www.semtech.com