SEMTECH SC194A

SC194A 1A Synchronous Buck Converter with Integrated Power Devices POWER MANAGEMENT Description Features The SC194A is a synchronous step-down converter with ‹ Up to 93% efŢ ciency integrated power devices. The SC194A is designed for ‹ Output current - 1A ‹ Input range - 2.7V to 5.5V single-cell Li-Ion battery applications, but can also be used ‹ Quiescent current - 17μA in Ţ xed 3.3V or 5V applications. The switching frequency is ‹ Four selectable output voltages nominally set to 1MHz, allowing the use of small inductors ‹ Dynamic voltage positioning capability and capacitors. The 1.3A maximum current rating of the ‹ Fixed 1MHz frequency or 750kHz to 1.25MHz internal MOSFET switches allows a DC output current of synchronized operation 1A. ‹ PSAVE operation to maximize efŢ ciency at light loads ‹ Minimal external components The SC194A has a ţ exible clocking methodology that ‹ Fast transient response allows it to be synchronized to an external oscillator or ‹ 100% duty cycle in dropout controlled by the internal oscillator. The device can ‹ Soft-start operate in either forced PWM mode or in PSAVE mode. If ‹ Over-temperature and short-circuit protection PSAVE mode is enabled the part will automatically enter ‹ Space-saving lead-free package - MLP-10, 3 x 3mm PFM at light loads to maintain maximum efŢ ciency across the full load range. Applications For noise sensitive applications, PSAVE mode can be ‹ Cell phones disabled by synchronizing to an external oscillator, or ‹ Wireless communication chipset power pulling the SYNC/PWM pin high. Shutdown turns off all ‹ Personal media player the control circuitry to achieve a typical shutdown current ‹ Notebook and sub-notebook computers of 0.1μA. ‹ PDAs and mobile communicators ‹ WLAN peripherals Typical Application Circuit L1 SC194A V OUT VIN LX V 1.8V IN 4.7μH EN 2.7V to 5.5V 1A SYNC/PWM VOUT C C IN OUT VID0 VID1 PGND 10μF 10μF MODE GND July 05, 2006 1 www.semtech.com SC194A PRELIMINARY 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 LEAD (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 = 3.6V, EN = V , SYNC/PWM = V , MODE = V , T = -40 to 85°C. Typical values are at T = 25°C. IN IN IN IN A A Parameter Symbol Conditions Min Typ Max Units Input Voltage Range V 2.7 5.5 V IN VOUT Accuracy V I = 0.5A, T = 25°C ±1 % OUT OUT A VOUT Temperature Accuracy V I = 0.5A, T = -40 to 85°C ±0.3 ±0.7 % OUT(T) OUT A V = 2.7V to 5.5V, V = 1.8V, IN OUT Line Regulation V ±0.4 ±0.65 % OUT LINE I = 0.5A, T = -40 to 85°C OUT A Load Regulation (PWM) V I = 0A to 1A, T = -40 to 85°C ±0.3 ±0.65 % OUT LOAD OUT A +1.3 +1.6 PSAVE Regulation V SYNC/PWM =GND, C =22 μF % OUT PSAVE OUT -0.3 -0.6 P-Channel On Resistance R I = 100mA 0.275 Ω DSP LX N-Channel On Resistance R I = 100mA 0.165 Ω DSN LX Start-Up Time T 5ms START P-Channel Current Limit I 1.33 1.9 2.47 A LIM(P) © 2006 Semtech Corp. 2 www.semtech.com SC194A PRELIMINARY 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 OUT OUT(Programmed) Shutdown Current I EN = GND, LX = OPEN 0.1 1 μA SD LX Leakage Current PMOS I LX = GND, EN = GND 0.1 2 μA LXP LX Leakage Current NMOS I LX = 3.6V, EN = GND -2 0.1 μA LXN Oscillator Frequency f 0.85 1.0 1.15 MHz OSC SYNC Frequency (upper) f 1.25 MHz SYNCU SYNC Frequency (lower) f 750 kHz SYNCL UVLO Threshold (upper) V 2.38 2.52 2.65 V UVL UVLO Hysteresis V 50 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 © 2006 Semtech Corp. 3 www.semtech.com SC194A PRELIMINARY POWER MANAGEMENT Ordering Information Pin ConŢ guration DEVICE PACKAGE (1)(2) SC194AMLTRT MLP 3x3-10 SC194AEVB Evaluation Board Ordering Information 1 10 LX VIN Notes: 1) Lead-free packaging only. This product is fully WEEE and RoHS compliant. TOP VIEW 2 9 PGND MODE 2) Available in tape and reel only. A reel contains 3000 devices. SYNC/ 3 8 GND PWM 4 7 VID1 EN T VOUT56 VID0 Programmable Output Voltage VID1 VID0 SC194A V OUT MLP10: 3X3 10 LEAD 0 0 1.0V 0 1 1.2V 1 0 1.5V 1 1 1.8V Marking Information © 2006 Semtech Corp. 4 www.semtech.com SC194A PRELIMINARY POWER MANAGEMENT Block Diagram Plimit Amp 1 VIN Current Amp EN 4 SYNC OSC & Slope 3 /PWM Generator Control 10 LX Logic PWM Comp 500mV PSAVE Error Amp Ref Comp Nlimit Amp 9 PGND 2 MODE VID1 7 Voltage Select 8 GND VID0 6 VOUT 5 © 2006 Semtech Corp. 5 www.semtech.com SC194A PRELIMINARY POWER MANAGEMENT Pin Descriptions Pin # Pin Name Pin Function 1 VIN Input power supply voltage 2 MODE MODE select pin - MODE = V to select 100% duty cycle function, MODE = GND to disable IN Oscillator synchronization input - Tie to V for forced PWM mode or GND to allow the part to enter PSAVE IN 3 SYNC/PWM mode at light loads. Apply an external clock signal for frequency synchronization. Enable digital input - a high input enables the SC194A, a low disables and reduces quiescent current to 4EN less than 1μA. In shutdown, LX becomes high impedance. 5 VOUT Regulated output voltage and feedback for SC194A Logic level bit 0 used in conjunction with VID1 to set the output voltage. Connect high or low as required 6 VID0 to select the desired output voltage. If not connected, the output voltage will be indeterminate. Logic level bit 1 used in conjunction with VID0 to set the output voltage. Connect high or low as required 7 VID1 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 for heatsinking purposes - not connected internally. Connects to ground plane using T multiple vias. PAD © 2006 Semtech Corp. 6 www.semtech.com SC194A PRELIMINARY POWER MANAGEMENT Applications Information SC194A Detailed Description • Over-voltage protection The SC194A 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 Thermal Shutdown is designed to operate in a Ţ xed-frequency PWM mode The device has a thermal shutdown feature to protect the across the full load range and can enter Power Save Mode SC194A if the junction temperature exceeds 145°C. In (PSAVE) utilizing Pulse Frequency Modulation (PFM) at thermal shutdown the on-chip power devices are disabled, light loads 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 uses the PMOS Current Limit current path, and it is ampliŢ ed and summed with the The PMOS and NMOS power devices of the buck switcher internal slope compensation network. The voltage stage are protected by current limit functions. In the feedback loop uses an internal feedback divider. The on- case of a short to ground on the output, the part enters time is determined by comparing the summed current frequency foldback mode, that causes the switching feedback and the output of the error ampliŢ er. The period frequency to divide by a factor determined by the output is set by the onboard oscillator or by an external clock voltage. This prevents the inductor current from "stair- attached to the SYNC/PWM pin. casing". The SC194A has an internal synchronous NMOS rectiŢ er Over-Voltage Protection and does not require a Schottky diode on the LX pin. Over-voltage protection is provided on the SC194A. In the event of an over-voltage on the output in switcher mode, Programmable Output Voltage the PWM drive is disabled, tri-stating the LX output. The The SC194A has four pre-determined output voltage part will not resume switching until the output voltage has values which can be individually selected by the correct fallen below 2% of the regulation voltage. programming of the VID0 and VID1 pins (see Programmable Output Voltage table on Page 4). This eliminates the need Soft-Start for external programming resistors saving PCB area and The soft-start mode is enabled after every shutdown cycle inventory. The VID pins can be statically tied to GND or to limit in-rush current. In conjunction with the frequency VIN for Ţ xed output conŢ gurations or they may be driven foldback, this controls the maximum current during start- by a microprocessor enabling the possibility of dynamic up. The PMOS current limit is stepped up through seven voltage adjustment for host equipment "sleep" states. soft-start levels to the full value by a timer driven from the internal oscillator. During soft-start, the switching Continuous Conduction & Oscillator Synchronization frequency is stepped by 1/8, 1/4, and 1/2 of the internal The SC194A is designed to operate in continuous oscillator frequency up to the full value, under control of conduction, Ţ xed-frequency mode. When the SYNC/ three output voltage thresholds. As soon as the output PWM pin is tied high the part runs in PWM mode using voltage is within 2% of the regulation voltage, soft-start the internal oscillator. The part can be synchronized to mode is disabled. an external clock by driving a clock signal into the SYNC/ PWM pin. The part synchronizes to the rising edge of the Power Save Mode Operation clock. The PSAVE mode may be selected by tying the SYNC/PWM pin to GND. Selecting PSAVE mode will enable the SC194A Protection Features to automatically activate/deactivate operation at light The SC194A provides the following protection features: loads maximizing efŢ ciency across the full load range. The SC194A automatically detects the load current at which it • Thermal shutdown should enter PSAVE mode. The SC194A is optimized to • Current limit track maximum efŢ ciency with respect to V . IN © 2006 Semtech Corp. 7 www.semtech.com SC194A PRELIMINARY 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 SC194A 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 that linearly above the maximum value in Ţ xed-frequency the inductor current ripple is similar to that in PWM mode. operation until the PMOS is active continuously. Once The minimum switching frequency during this period is the PMOS is switched on continuously, the output voltage limited to 650kHz. tracks the input voltage minus the voltage drop across the PMOS power device and inductor according to the The SC194A automatically detects when to exit PSAVE following relationship: mode by monitoring V . For the SC194A to exit PSAVE OUT mode, the load must be increased, causing V to V VOUT OUT = = V VII N N − − IIOUT OUT × × ( ( R RDSP DSP + + R RIND IND ) ) OUT decrease until the power save exit threshold is reached. PSAVE levels are set high to minimize the undershoot where, when exiting PSAVE. The lower PSAVE comparator level V = Output voltage OUT is set +0.7% above V , and the upper comparator level V = Input voltage OUT IN at +1.5% above V , with the exit threshold at -2% below I = Output current OUT OUT V . R = PMOS switch ON resistance OUT DSP R = Series resistance of the inductor IND If PSAVE operation is required then a 22μF output capacitor must be used. The 100% duty cycle can only operate for a programmed output voltage of 1.8V. With an output voltage of 1.8V, 100% duty cycle mode will Power Save Operation only be required to maintain regulation if V falls below a IN minimum value shown in the graph below. Higher Load Applied OFF BURST Minimum V for Fixed Frequency Operation Vs. R IN IND 1.5% 3 0.7% PSAVE Mode at Light Load PWM Mode at Medium/ 2.95 High Load V OUT -2% 2.9 2.85 Inductor Current 2.8 2.75 V = 1.8V OUT I =1A OUT 0 A 2.7 Time 0.05 0.1 0.15 0.2 0.25 0.3 Inductor DC Resistance (Ω) © 2006 Semtech Corp. 8 www.semtech.com V (V) IN SC194A PRELIMINARY POWER MANAGEMENT Applications Information (Cont.) The SC194A is designed for use with a 4.7μH inductor. Output voltage ripple is a combination of the voltage The magnitude of the inductor current ripple is dependent ripple from the inductor current charging and discharging on the inductor value and can be determined by the the output capacitor and the voltage created from the following equation: 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 V V the following equation: OUT OUT ΔI = ——— 1 - ——— L ( ) L × f V OSC IN ΔV = ΔI × ESR OUT(ESR) L(ripple) COUT This equation demonstrates the relationship between input voltage, output voltage, and inductor ripple current. Capacitors with X7R or X5R ceramic dielectric are strongly recommended for their low ESR and superior The inductor should have a low DCR to minimize the temperature and voltage characteristics. Y5V capacitors conduction losses and maximize efŢ ciency. As a minimum should not be used as their temperature coefŢ cients requirement, the DC current rating of the inductor make them unsuitable for this application. Table 2 lists should be equal to the maximum load current plus half the manufacturers of recommended capacitor options. of the inductor current ripple as shown by the following equation: ΔI L I = I + —— L(PK) OUT(MAX) 2 Final inductor selection will depend on various design Table 1: Recommended Inductors considerations such as efŢ ciency, EMI, size and cost. Saturation Dimensions Table 1 lists the manufacturers of practical inductor Value DCR Tolerance Manufacturer/Part # Current (LxWxH) μH Ω ±% options. A mm BI Technologies 4.7 0.072 1.32 20 4.7 × 4.7 × 3.0 C Selection IN HM66304R7 The source input current to a buck converter is non- Coilcraft 4.7 0.09 1.5 20 6.6 × 4.5 × 3.0 D01608C-472ML continuous. To prevent large input voltage ripple a low ESR ceramic capacitor is required. A minimum value of TDK 4.7 0.101 1.07 30 4.3 × 4.0 × 1.8 VLCF4018T- 4R7N1R0-2 10μF should be used for sufŢ cient input voltage Ţ ltering and a 22μF should be used for improved input voltage Ţ ltering. Table 2: Recommended Capacitors C Selection OUT Rated Value Temperature The internal compensation is designed to work with a Manufacturer/Part # Voltage Case Size μF Characteristic VDC certain output Ţ lter corner frequency deŢ ned by the equation: Murata 22 6.3 X5R 0805 GRM21BR60J226ME39L 1 fc = 2π√L × C OUT Murata GRM188R60J106 10 6.3 X5R 0603 MKE19 TDK This single pole Ţ lter is designed to operate with a 10 6.3 X5R 0603 C2012X5R0J106K minimum output capacitor value of 10μF. Larger output capacitor values will improve transient performance. If Note: Where PSAVE operation is required 22μF must be used for C . OUT PSAVE operation is required the minimum capacitor value is 22μF. © 2006 Semtech Corp. 9 www.semtech.com SC194A PRELIMINARY POWER MANAGEMENT Applications Information (Cont.) PCB Layout Considerations 2. Route the output voltage feedback path away from the Poor layout can degrade the performance of the DC-DC inductor and LX node to minimize noise and magnetic converter and can contribute to EMI problems, ground interference. bounce and resistive voltage losses. Poor regulation and instability can result. 3. Maximize ground metal on the component side to improve the return connection and thermal dissipation. Separation between the LX node and GND should be A few simple design rules can be implemented to ensure maintained to avoid coupling of switching noise to the good layout: ground plane. 1. Place the inductor and Ţ lter capacitors as close to the 4. Use a ground plane with several vias connecting to device as possible and use short wide traces between the component side ground to further reduce noise interference on sensitive circuit nodes. the power components. © 2006 Semtech Corp. 10 www.semtech.com SC194A PRELIMINARY POWER MANAGEMENT Typical Characteristics EfŢ ciency vs. Load Current V = 1.8V EfŢ ciency vs. Load Current V = 1.5V OUT OUT 100 100 90 90 80 80 V =4.2V PSAVE IN VIN=4.2V PSAVE 70 70 VIN=3.6V PSAVE VIN=3.6V PSAVE 60 60 V =2.7V PSAVE IN V =2.7V PSAVE V =4.2V PWM IN IN 50 50 VIN=4.2V PWM 40 40 VIN=3.6V PWM VIN=3.6V PWM 30 30 V =2.7V PWM IN VIN=2.7V PWM 20 20 10 10 0 0 0.0001 0.001 0.01 0.1 1 0.0001 0.001 0.01 0.1 1 I (A) I (A) OUT OUT EfŢ ciency vs. Load Current V = 1.2V EfŢ ciency vs. Load Current V = 1.0V OUT OUT 100 100 90 90 80 80 V =2.7V PSAVE IN V =4.2V PSAVE 70 IN 70 VIN=3.6V PSAVE VIN=2.7V PWM 60 V =3.6V PSAVE IN 60 VIN=2.7V PSAVE 50 50 V =4.2V PSAVE V =3.6V PWM IN IN VIN=4.2V PWM 40 40 VIN=3.6V PWM 30 30 V =4.2V PWM IN V =2.7V PWM IN 20 20 10 10 0 0 0.0001 0.001 0.01 0.1 1 0.0001 0.001 0.01 0.1 1 I (A) OUT IOUT (A) EfŢ ciency vs. Input Voltage PWM to PSAVE Hysteresis 95 100 PSAVE Exit for increasing IOUT PSAVE Entry for decreasing IOUT 90 V =1.8V,PWM 95 OUT V =1.8V,PSAVE OUT 90 PSAVE Mode I increasing OUT 85 PSAVE MODE I decreasing OUT 85 PWM Mode 80 80 VOUTt=1V,PSAVE VOUT=1V,PWM 75 75 70 70 0.001 0.01 0.1 1 2.5 3.5 4.0 4.5 5.0 5.5 3.0 IOUT (A) Vin(V) I =500 mA(PWM)/50 mA(PSAVE) OUT © 2006 Semtech Corp. 11 www.semtech.com Efficiency (%) Efficiency (%) Eff(%) Efficiency (%) Efficiency (%) Efficiency (%) SC194A PRELIMINARY POWER MANAGEMENT Typical Characteristics (Cont.) V vs. V V vs. I , V =1.8V, PWM OUT OUT OUT OUT IN 1.84 1.8025 1.8020 1.8015 1.83 V =1.8V PSAVE OUT 1.8010 IOUT=50mA 1.8005 1.82 1.8000 1.7995 VOUT=1.8V PWM IOUT=500mA 1.7990 1.81 1.7985 1.7980 1.80 1.7975 0.2 0.4 0.6 0.8 11.2 0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 I (A) OUT V (V) IN V vs. Temperature OUT Quiescent Current vs. Input Voltage V =1.8V, PWM OUT 1.8090 PSAVE Mode 22 1.8085 21 TA = 85 °C 1.8080 20 1.8075 19 1.8070 18 TA = 25 °C 1.8065 17 1.8060 16 1.8055 15 1.8050 T = 40 °C 14 A 1.8045 13 1.8040 12 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 2.5 3 3.5 4 4.5 5 5.5 6 ° V (V) T ( C) IN A Quiescent Current vs. Input Voltage P-Channel R vs. Input Voltage DSON PWM Mode 0.40 6 T = 85 °C A TA = -40 °C 0.35 5.5 TA = 85 °C TA = 25 °C 0.30 5 TA = 25 °C 0.25 4.5 TA = -40 °C 0.20 4 0.15 3.5 0.10 3 2.7 3.2 3.7 4.2 4.7 5.2 2.5 3 3.5 4 4.5 5 5.5 6 VIN (V) V (V) IN © 2006 Semtech Corp. 12 www.semtech.com Vout(V) V (V) OUT Quiescent Current (mA) R DSON (Ω) V (V) OUT Quiescent Current (μA) SC194A PRELIMINARY POWER MANAGEMENT Typical Characteristics (Cont.) N-Channel R vs. Input Voltage Switching Frequency vs. Temperature DSON 0.22 1050 VIN = 5.5V 1040 VIN = 3.6V 0.20 1030 TA = 85 °C 1020 VIN = 2.7V 0.18 1010 TA = 25 °C 1000 0.16 990 TA = -40 °C 0.14 980 970 0.12 960 0.10 950 -50 -30 -10 10 30 50 70 90 110 130 2.7 3.2 3.7 4.2 5.2 4.7 VIN (V) TJ = (°C) PSAVE Operation 100% Duty Cycle Mode V (50mV/div) OUT V (20mV/div) OUT I (1A/div) LOAD I (200mA/div) L V (5V/div) V (2V/div) LX LX Time (400ns/div) Time (1us/div) Condition V =3.6V, V =1.8V, l =150mA, Condition V =2.6V, V =1.8V, l =1.4A, IN OUT OUT IN OUT OUT SYNC/PWM=1.15MHz ext clock SYNC/PWM=GND PWM Operation PSAVE Start up EN (2V/div) V (10mV/div) OUT V (1V/div) OUT I (200mA/div) L V (5V/div) LX l (100mA/div) IN Time (1us/div) Time (200us/div) Condition V =3.6V, V =1.8V, l =150mA, IN OUT OUT Condition V =3.6V, V =1.8V, l =10mA, IN OUT OUT SYNC/PWM=V IN SYNC/PWM=GND © 2006 Semtech Corp. 13 www.semtech.com R (Ω) DSON Switching Frequency (kHz) SC194A PRELIMINARY POWER MANAGEMENT Typical Characteristics (Cont.) PWM Start-up Load Transient Response PWM EN (2V/div) V (1V/div) OUT V (100mV/div) OUT I (1A/div) l (100mA/div) LOAD IN Time (100us/div) Time (200us/div) Condition V =3.6V, V =1.8V, l =1A to 100mA, Condition V =3.6V, V =1.8V, l =10mA, IN OUT OUT IN OUT OUT SYNC/PWM=V SYNC/PWM=V IN IN Load Transient Response PSAVE VID Code Change VID0 (2V/div) V (100mV/div) OUT V (200mV/div) OUT I (1A/div) LOAD Time (100us/div) Time (400us/div) Condition V =3.6V, V =1.8V, l =1A to 100 mA, Condition V =3.6V, V =1.8V to 1.5V, l =1A, IN OUT OUT IN OUT OUT SYNC/PWM=GND SYNC/PWM=V IN © 2006 Semtech Corp. 14 www.semtech.com SC194A PRELIMINARY POWER MANAGEMENT Applications Circuits V = 1.8V with PSAVE and 100% Duty Cycle OUT L1 SC194A V OUT VIN LX 1.8V V IN EN 4.7μH 1A 2.7V to 5.5V SYNC/PWM VOUT C C IN OUT VID0 VID1 PGND 10μF 22μF MODE GND Mobile Voltage Positioning for Reduced System Dissipation in "Sleep" Modes V IN V OUT 2.7V to 5.5V 1.8V C IN norm L1 SC194A 10μF V OUT VIN LX 1.2V EN 4.7μH “sleep” SYNC/PWM VOUT C OUT “Sleep” Flag from VID0 VID1 PGND uProc 22μF Changes voltage MODE GND from 1.8V to 1.2V V = 1.0V with Forced PWM and no 100% Duty Cycle OUT L1 SC194A V OUT VIN LX V 1V IN 4.7μH EN 2.7V to 5.5V 1A SYNC/PWM VOUT C C IN OUT VID0 VID1 PGND 10μF 10μF MODE GND © 2006 Semtech Corp. 15 www.semtech.com SC194A PRELIMINARY POWER MANAGEMENT Outline Drawing - MLP-10 A E DIMENSIONS B INCHES MILLIMETERS DIM MIN NOM MAX MIN NOM MAX - - A .031 .039 0.80 1.00 - - A1 .000 .002 0.00 0.05 - (.008) - - (0.20) - A2 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 bxN e 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. © 2006 Semtech Corp. 16 www.semtech.com SC194A PRELIMINARY POWER MANAGEMENT Land Pattern - MLP-10 K DIMENSIONS DIM INCHES MILLIMETERS (.112) (2.85) C G .075 1.90 H .055 1.40 H 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 © 2006 Semtech Corp. 17 www.semtech.com