SC194A

SC194A 1A Synchronous Buck Converter with Integrated Power Devices POWER MANAGEMENT Description The SC194A is a synchronous step-down converter with integrated power devices. The SC194A is designed for single-cell Li-Ion battery applications, but can also be used in fixed 3.3V or 5V applications. The switching frequency is nominally set to 1MHz, allowing the use of small inductors and capacitors. The 1.3A maximum current rating of the internal MOSFET switches allows a DC output current of 1A. The SC194A has a flexible clocking methodology that allows it to be synchronized to an external oscillator or controlled by the internal oscillator. The device can operate in either forced PWM mode or in PSAVE mode. If PSAVE mode is enabled the part will automatically enter PFM at light loads to maintain maximum efficiency 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. Features Up to 93% efficiency Output current - 1A Input range - 2.7V to 5.5V Quiescent current - 17μA Four selectable output voltages Dynamic voltage positioning capability Fixed 1MHz frequency or 750kHz to 1.25MHz synchronized operation PSAVE operation to maximize efficiency at light loads Minimal external components Fast transient response 100% duty cycle in dropout Soft-start Over-temperature and short-circuit protection Space-saving lead-free package - MLP-10, 3 x 3mm Applications Cell phones Wireless communication chipset power Personal media player Notebook and sub-notebook computers PDAs and mobile communicators WLAN peripherals Typical Application Circuit SC194A VIN 2.7V to 5.5V CIN 10μF VIN EN SYNC/PWM VID0 VID1 MODE LX VOUT PGND GND L1 4.7μH COUT 10μF VOUT 1.8V 1A July 05, 2006 1 www.semtech.com SC194A POWER MANAGEMENT Absolute Maximum Ratings Parameter Input Supply Voltage Logic Inputs (SYNC/PWM, EN, MODE, VID0, VID1) Output Voltage LX Voltage Thermal Impedance Junction to Ambient(1) VOUT Short-Circuit to GND Operating Ambient Temperature Range Storage Temperature Junction Temperature Peak IR Reflow Temperature ESD Protection Level (2) Symbol VIN VN VOUT VLX θJA tSC TA TS TJC TLEAD VESD Maximum -0.3 to 7 -0.3 to VIN+0.3, 7V Max -0.3 to VIN+0.3, 7V Max -1 to VIN +1, 7V Max 40 Continuous -40 to +85 -60 to +160 -40 to +150 260 2 PRELIMINARY 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 recommended. Units V V V V °C/W s °C °C °C °C kV 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: VIN = 3.6V, EN = VIN, SYNC/PWM = VIN, MODE = VIN , TA = -40 to 85°C. Typical values are at TA = 25°C. Parameter Input Voltage Range VOUT Accuracy VOUT Temperature Accuracy Line Regulation Load Regulation (PWM) PSAVE Regulation P-Channel On Resistance N-Channel On Resistance Start-Up Time P-Channel Current Limit © 2006 Semtech Corp. Symbol VIN VOUT VOUT(T) VOUT LINE VOUT LOAD VOUT PSAVE RDSP RDSN TSTART ILIM(P) Conditions Min 2.7 Typ Max 5.5 ±1 Units V % % % % % Ω Ω IOUT = 0.5A, TA = 25°C IOUT = 0.5A, TA = -40 to 85°C VIN = 2.7V to 5.5V, VOUT = 1.8V, IOUT = 0.5A, TA = -40 to 85°C IOUT = 0A to 1A, TA = -40 to 85°C SYNC/PWM =GND, COUT=22 μF ILX = 100mA ILX = 100mA ±0.3 ±0.4 ±0.3 +1.3 -0.3 0.275 0.165 ±0.7 ±0.65 ±0.65 +1.6 -0.6 5 1.33 2 1.9 2.47 ms A www.semtech.com SC194A POWER MANAGEMENT Electrical Characteristics (Cont.) Parameter Quiescent Current Shutdown Current LX Leakage Current PMOS LX Leakage Current NMOS Oscillator Frequency SYNC Frequency (upper) SYNC Frequency (lower) UVLO Threshold (upper) UVLO Hysteresis Thermal Shutdown Thermal Shutdown Hysteresis Logic Input High Logic Input Low Logic Input Current High Logic Input Current Low Symbol IQ ISD ILXP ILXN fOSC fSYNCU fSYNCL VUVL VUVLHYS TSD TSD-HYS VIH VIL IIH IIL EN, SYNC/PWM, VID0, VID1, MODE EN, SYNC/PWM, VID0, VID1, MODE EN, SYNC/PWM, VID0, VID1, MODE EN, SYNC/PWM, VID0, VID1, MODE -2 -2 0.1 0.1 1.6 0.6 2 2 2.38 2.52 50 145 10 Conditions SYNC/PWM = GND, IOUT = 0A, VOUT = 1.04 x VOUT(Programmed) EN = GND, LX = OPEN LX = GND, EN = GND LX = 3.6V, EN = GND -2 0.85 1.25 750 2.65 Min Typ 17 0.1 0.1 0.1 1.0 1.15 PRELIMINARY Max 28 1 2 Units μA μA μA μA MHz MHz kHz V mV °C °C V V μA μA © 2006 Semtech Corp. 3 www.semtech.com SC194A POWER MANAGEMENT Pin Configuration Ordering Information DEVICE SC194AMLTRT(1)(2) 1 2 3 4 5 T 10 LX PGND GND VID1 VID0 PRELIMINARY PACKAGE MLP 3x3-10 Evaluation Board VIN MODE SYNC/ PWM EN VOUT TOP VIEW 9 8 7 6 Notes: 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. Ordering Information SC194AEVB Programmable Output Voltage VID1 VID0 0 1 0 1 SC194A VOUT 1.0V 1.2V 1.5V 1.8V MLP10: 3X3 10 LEAD 0 0 1 1 Marking Information © 2006 Semtech Corp. 4 www.semtech.com SC194A POWER MANAGEMENT Block Diagram PRELIMINARY Plimit Amp 1 Current Amp VIN EN 4 SYNC /PWM 3 OSC & Slope Generator Control Logic PWM Comp 10 LX 500mV Ref Error Amp PSAVE Comp Nlimit Amp 9 PGND MODE 2 VID1 VID0 7 6 Voltage Select 8 GND VOUT 5 © 2006 Semtech Corp. 5 www.semtech.com SC194A POWER MANAGEMENT Pin Descriptions Pin # 1 2 3 4 5 6 7 8 9 10 T Pin Name VIN MODE SYNC/PWM EN VOUT VID0 VID1 GND PGND LX THERMAL PAD Pin Function Input power supply voltage MODE select pin - MODE = VIN to select 100% duty cycle function, MODE = GND to disable Oscillator synchronization input - Tie to VIN for forced PWM mode or GND to allow the part to enter PSAVE 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 less than 1μA. In shutdown, LX becomes high impedance. 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 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 to select the desired output voltage. If not connected, the output voltage will be indeterminate. Ground Power Ground Inductor connection to the switching FETs Pad for heatsinking purposes - not connected internally. Connects to ground plane using multiple vias. PRELIMINARY © 2006 Semtech Corp. 6 www.semtech.com SC194A POWER MANAGEMENT Applications Information SC194A Detailed Description The SC194A is a synchronous step-down Pulse Width Modulated (PWM), DC-DC converter utilizing a 1MHz fixed-frequency current mode architecture. The device is designed to operate in a fixed-frequency PWM mode across the full load range and can enter Power Save Mode (PSAVE) utilizing Pulse Frequency Modulation (PFM) at light loads to maximize efficiency. Operation During normal operation the PMOS MOSFET is activated on each rising edge of the internal oscillator. Current feedback for the switching regulator uses the PMOS current path, and it is amplified and summed with the internal slope compensation network. The voltage feedback loop uses an internal feedback divider. The ontime is determined by comparing the summed current feedback and the output of the error amplifier. The period is set by the onboard oscillator or by an external clock attached to the SYNC/PWM pin. The SC194A has an internal synchronous NMOS rectifier and does not require a Schottky diode on the LX pin. Programmable Output Voltage The SC194A has four pre-determined output voltage values which can be individually selected by the correct programming of the VID0 and VID1 pins (see Programmable Output Voltage table on Page 4). This eliminates the need for external programming resistors saving PCB area and inventory. The VID pins can be statically tied to GND or VIN for fixed output configurations or they may be driven by a microprocessor enabling the possibility of dynamic voltage adjustment for host equipment "sleep" states. Continuous Conduction & Oscillator Synchronization The SC194A is designed to operate in continuous conduction, fixed-frequency mode. When the SYNC/ PWM pin is tied high the part runs in PWM mode using the internal oscillator. The part can be synchronized to an external clock by driving a clock signal into the SYNC/ PWM pin. The part synchronizes to the rising edge of the clock. Protection Features The SC194A provides the following protection features: • Thermal shutdown • Current limit © 2006 Semtech Corp. 7 PRELIMINARY • Over-voltage protection • Soft-start Thermal Shutdown The device has a thermal shutdown feature to protect the SC194A if the junction temperature exceeds 145°C. In thermal shutdown the on-chip power devices are disabled, tri-stating the LX output. Switching will resume when the temperature drops by 10°C. During this time if the output voltage decreases by more than 60% of its programmed value, a soft-start will be invoked. Current Limit The PMOS and NMOS power devices of the buck switcher stage are protected by current limit functions. In the case of a short to ground on the output, the part enters frequency foldback mode, that causes the switching frequency to divide by a factor determined by the output voltage. This prevents the inductor current from "staircasing". Over-Voltage Protection Over-voltage protection is provided on the SC194A. In the event of an over-voltage on the output in switcher mode, the PWM drive is disabled, tri-stating the LX output. The part will not resume switching until the output voltage has fallen below 2% of the regulation voltage. Soft-Start The soft-start mode is enabled after every shutdown cycle to limit in-rush current. In conjunction with the frequency foldback, this controls the maximum current during startup. The PMOS current limit is stepped up through seven soft-start levels to the full value by a timer driven from the internal oscillator. During soft-start, the switching frequency is stepped by 1/8, 1/4, and 1/2 of the internal oscillator frequency up to the full value, under control of three output voltage thresholds. As soon as the output voltage is within 2% of the regulation voltage, soft-start mode is disabled. Power Save Mode Operation The PSAVE mode may be selected by tying the SYNC/PWM pin to GND. Selecting PSAVE mode will enable the SC194A to automatically activate/deactivate operation at light loads maximizing efficiency across the full load range. The SC194A automatically detects the load current at which it should enter PSAVE mode. The SC194A is optimized to track maximum efficiency with respect to VIN. www.semtech.com SC194A POWER MANAGEMENT Applications Information (Cont.) In PSAVE mode VOUT is driven from a lower level to an upper level by a switching burst. Once the upper level has been reached the switching is stopped and the quiescent current is reduced. VOUT falls from the upper to lower levels in this low current state as the load current discharges the output capacitor. The burst-to-off period in PSAVE will decrease as the load current reduces. The PSAVE switching burst frequency is controlled so that the inductor current ripple is similar to that in PWM mode. The minimum switching frequency during this period is limited to 650kHz. The SC194A automatically detects when to exit PSAVE mode by monitoring VOUT . For the SC194A to exit PSAVE mode, the load must be increased, causing VOUT to decrease until the power save exit threshold is reached. PSAVE levels are set high to minimize the undershoot when exiting PSAVE. The lower PSAVE comparator level is set +0.7% above VOUT, and the upper comparator level at +1.5% above VOUT, with the exit threshold at -2% below VOUT. If PSAVE operation is required then a 22μF output capacitor must be used. PRELIMINARY 100% Duty Cycle Operation The 100% duty cycle mode may be selected by connecting the MODE pin high. This will allow the SC194A to maintain output regulation under low input voltage/high output voltage conditions. In 100% duty cycle operation, as the input supply drops toward the output voltage, the PMOS on-time increases linearly above the maximum value in fixed-frequency operation until the PMOS is active continuously. Once the PMOS is switched on continuously, the output voltage tracks the input voltage minus the voltage drop across the PMOS power device and inductor according to the following relationship: VOUT = VI N − IOUT × ( RDSP + RIND ) where, VOUT VIN IOUT RDSP RIND = Output voltage = Input voltage = Output current = PMOS switch ON resistance = Series resistance of the inductor 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 only be required to maintain regulation if VIN falls below a minimum value shown in the graph below. Minimum VIN for Fixed Frequency Operation Vs. RIND 3 Power Save Operation BURST OFF Higher Load Applied 1.5% 0.7% PSAVE Mode at Light Load VOUT PWM Mode at Medium/ High Load 2.95 -2% VIN (V) 2.9 2.85 Inductor Current 2.8 2.75 0A Time VOUT = 1.8V IOUT =1A 2.7 0.05 0.1 0.15 0.2 0.25 0.3 Inductor DC R esistance (Ω) © 2006 Semtech Corp. 8 www.semtech.com SC194A POWER MANAGEMENT Applications Information (Cont.) The SC194A is designed for use with a 4.7μH inductor. The magnitude of the inductor current ripple is dependent on the inductor value and can be determined by the following equation: VOUT ΔIL = ——— L × fOSC PRELIMINARY 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: ΔVOUT(ESR) = ΔIL(ripple) × ESRCOUT Capacitors with X7R or X5R ceramic dielectric are strongly recommended for their low ESR and superior temperature and voltage characteristics. Y5V capacitors should not be used as their temperature coefficients make them unsuitable for this application. Table 2 lists the manufacturers of recommended capacitor options. ( VOUT 1 - ——— VIN ) This equation demonstrates the relationship between input voltage, output voltage, and inductor ripple current. The inductor should have a low DCR to minimize the conduction losses and maximize efficiency. As a 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: ΔIL IL(PK) = IOUT(MAX) + —— 2 Final inductor selection will depend on various design considerations such as efficiency, EMI, size and cost. Table 1 lists the manufacturers of practical inductor options. CIN Selection The source input current to a buck converter is noncontinuous. To prevent large input voltage ripple a low ESR ceramic capacitor is required. A minimum value of 10μF should be used for sufficient input voltage filtering and a 22μF should be used for improved input voltage filtering. COUT Selection The internal compensation is designed to work with a certain output filter corner frequency defined by the equation: fc = 1 2π√L × COUT Table 1: Recommended Inductors Manufacturer/Part # Value μH DCR Ω Saturation Current A Tolerance ±% Dimensions (LxWxH) mm BI Technologies HM66304R7 Coilcraft D01608C-472ML TDK VLCF4018T- 4R7N1R0-2 4.7 0.072 1.32 20 4.7 × 4.7 × 3.0 4.7 0.09 1.5 20 6.6 × 4.5 × 3.0 4.7 0.101 1.07 30 4.3 × 4.0 × 1.8 Table 2: Recommended Capacitors Manufacturer/Part # Value μF Rated Voltage VDC Temperature Characteristic Case Size Murata GRM21BR60J226ME39L Murata GRM188R60J106 MKE19 TDK C2012X5R0J106K 22 6.3 X5R 0805 10 6.3 X5R 0603 This single pole filter 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. © 2006 Semtech Corp. 9 10 6.3 X5R 0603 Note: Where PSAVE operation is required 22μF must be used for COUT. www.semtech.com SC194A POWER MANAGEMENT Applications Information (Cont.) PCB Layout Considerations Poor layout can degrade the performance of the DC-DC converter and can contribute to EMI problems, ground bounce and resistive voltage losses. Poor regulation and instability can result. A few simple design rules can be implemented to ensure good layout: 1. Place the inductor and filter capacitors as close to the device as possible and use short wide traces between the power components. PRELIMINARY 2. Route the output voltage feedback path away from the inductor and LX node to minimize noise and magnetic interference. 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 maintained to avoid coupling of switching noise to the ground plane. 4. Use a ground plane with several vias connecting to the component side ground to further reduce noise interference on sensitive circuit nodes. © 2006 Semtech Corp. 10 www.semtech.com SC194A POWER MANAGEMENT Typical Characteristics Efficiency vs. Load Current VOUT = 1 .8V 100 90 80 70 VIN=4.2V PSAVE VIN=3.6V PSAVE PRELIMINARY Efficiency vs. Load Current VOUT = 1 .5V 100 90 80 70 VIN=4.2V PSAVE VIN=3.6V PSAVE Efficiency (%) 60 50 40 30 20 10 0 0.0001 Efficiency (%) VIN=2.7V PSAVE VIN=4.2V PWM 60 50 40 30 20 10 0 VIN=2.7V PSAVE VIN=4.2V PWM VIN=3.6V PWM VIN=2.7V PWM VIN=3.6V PWM VIN=2.7V PWM 0.001 0.01 IOUT (A) 0.1 1 0.0001 0.001 0.01 IOUT (A) 0.1 1 Efficiency vs. Load Current VOUT = 1 .2V 100 90 80 70 Efficiency (%) VIN=4.2V PSAVE VIN=3.6V PSAVE Efficiency vs. Load Current VOUT = 1 .0V 100 90 80 70 Efficiency (%) VIN=2.7V PSAVE VIN=3.6V PSAVE VIN=2.7V PWM 60 50 40 30 20 10 0 0.0001 VIN=2.7V PSAVE 60 50 40 30 VIN=4.2V PWM VIN=3.6V PWM VIN=2.7V PWM VIN=4.2V PSAVE VIN=3.6V PWM VIN=4.2V PWM 20 10 0 0.001 0.01 IOUT (A) 0.1 1 0.0001 0.001 0.01 IOUT (A) 0.1 1 Efficiency vs. Input Voltage 95 100 PWM to PSAVE Hysteresis PSAVE Exit for increasing IOUT PSAVE Entry for decreasing IOUT 95 VOUT=1.8V,PWM VOUT=1.8V,PSAVE 90 Efficiency (%) 90 85 PSAVE MODE IOUT decreasing PSAVE Mode IOUT increasing Eff(%) 85 80 PWM Mode 80 VOUT=1V,PWM VOUTt=1V,PSAVE 75 75 70 2.5 3.0 3.5 4.0 Vin(V) 4.5 5.0 5.5 70 0.001 0.01 IOUT (A) 0.1 1 IOUT=500 mA(PWM)/50 mA(PSAVE) © 2006 Semtech Corp. 11 www.semtech.com SC194A POWER MANAGEMENT Typical Characteristics (Cont.) VOUT vs. VIN 1.84 1.8025 1.8020 PRELIMINARY VOUT vs. IOUT, VOUT=1.8V, PWM 1.83 1.8015 VOUT=1.8V PSAVE IOUT=50mA 1.8010 1.8005 VOUT (V) 1.82 VOUT=1.8V PWM IOUT=500mA VOUT (V) 1.8000 1.7995 1.7990 1.7985 1.7980 1.81 1.80 2.5 1.7975 3.0 3.5 4.0 VIN (V) 4.5 5.0 5.5 6.0 0 0.2 0.4 0.6 IOUT (A) 0.8 1 1.2 VOUT vs. Temperature VOUT=1.8V, PWM 1.8090 1.8085 1.8080 1.8075 1.8070 Vout(V) Quiescent Current (μA) 22 21 Quiescent Current vs. Input Voltage PSAVE Mode TA = 85 °C 20 19 18 17 16 15 14 13 TA = 40 °C TA = 25 °C 1.8065 1.8060 1.8055 1.8050 1.8045 1.8040 -50 -40 -30 -20 -10 0 10 20 TA(°C) 30 40 50 60 70 80 90 12 2.5 3 3.5 4 VIN (V) 4.5 5 5.5 6 Quiescent Current vs. Input Voltage 6 PWM Mode T A = 85 °C TA = -40 °C P-Channel RDSON vs. Input Voltage 0.40 5.5 TA = 25 °C 0.35 T A = 85 °C Quiescent Current (m A) 5 0.30 TA = 25 °C R DSON (Ω) 4.5 0.25 TA = -40 °C 4 0.20 3.5 0.15 3 2.5 3 3.5 4 VIN (V) 4.5 5 5.5 6 0.10 2.7 3.2 3.7 VIN (V) 4.2 4.7 5.2 © 2006 Semtech Corp. 12 www.semtech.com SC194A POWER MANAGEMENT Typical Characteristics (Cont.) N-Channel RDSON vs. Input Voltage 0.22 PRELIMINARY Switching Frequency vs. Temperature 1050 1040 VIN = 5.5V VIN = 3.6V 0.20 Switching Frequency (kHz) TA = 85 °C 1030 1020 1010 1000 990 980 970 960 VIN = 2.7V 0.18 R DSON (Ω) 0.16 TA = 25 °C 0.14 TA = -40 °C 0.12 0.10 2.7 3.2 3.7 4.2 VIN (V) 4.7 5.2 950 -50 -30 -10 10 30 TJ = (°C) 50 70 90 110 130 100% Duty Cycle Mode VOUT (50mV/div) PSAVE Operation VOUT (20mV/div) ILOAD (1A/div) IL (200mA/div) VLX (2V/div) VLX (5V/div) Time (400ns/div) Condition VIN=2.6V, VOUT=1.8V, lOUT=1.4A, SYNC/PWM=1.15MHz ext clock Time (1us/div) Condition VIN=3.6V, VOUT=1.8V, lOUT=150mA, SYNC/PWM=GND PWM Operation VOUT (10mV/div) PSAVE Start up EN (2V/div) IL (200mA/div) VLX (5V/div) VOUT (1V/div) lIN (100mA/div) Time (1us/div) Condition VIN=3.6V, VOUT=1.8V, lOUT=150mA, SYNC/PWM=VIN Time (200us/div) Condition VIN=3.6V, VOUT=1.8V, lOUT=10mA, SYNC/PWM=GND © 2006 Semtech Corp. 13 www.semtech.com SC194A POWER MANAGEMENT Typical Characteristics (Cont.) PWM Start-up EN (2V/div) VOUT (1V/div) VOUT (100mV/div) PRELIMINARY Load Transient Response PWM lIN (100mA/div) Time (200us/div) Condition VIN=3.6V, VOUT=1.8V, lOUT=10mA, SYNC/PWM=VIN Time (100us/div) Condition VIN=3.6V, VOUT=1.8V, lOUT=1A to 100mA, SYNC/PWM=VIN ILOAD (1A/div) Load Transient Response PSAVE VID Code Change VID0 (2V/div) VOUT (100mV/div) VOUT (200mV/div) ILOAD (1A/div) Time (100us/div) Condition VIN=3.6V, VOUT=1.8V, lOUT=1A to 100 mA, SYNC/PWM=GND Time (400us/div) Condition VIN=3.6V, VOUT=1.8V to 1.5V, lOUT=1A, SYNC/PWM=VIN © 2006 Semtech Corp. 14 www.semtech.com SC194A POWER MANAGEMENT Applications Circuits VOUT = 1 .8V with PSAVE and 100% Duty Cycle PRELIMINARY SC194A VIN 2.7V to 5.5V CIN 10μF VIN EN SYNC/PWM VID0 VID1 MODE LX VOUT PGND GND L1 4.7μH COUT 22μF VOUT 1.8V 1A Mobile Voltage Positioning for Reduced System Dissipation in "Sleep" Modes VIN 2.7V to 5.5V CIN 10μF SC194A VIN EN SYNC/PWM VID0 VID1 MODE LX 4.7μH VOUT PGND GND COUT 22μF L1 VOUT 1.8V norm VOUT 1.2V “sleep” “Sleep” Flag from uProc Changes voltage from 1.8V to 1.2V VOUT = 1 .0V with Forced PWM and no 100% Duty Cycle SC194A VIN 2.7V to 5.5V CIN 10μF VIN EN SYNC/PWM VID0 VID1 MODE LX VOUT PGND GND L1 4.7μH COUT 10μF VOUT 1V 1A © 2006 Semtech Corp. 15 www.semtech.com SC194A POWER MANAGEMENT Outline Drawing - MLP-10 PRELIMINARY A E B DIM A A1 A2 b C D E e L N aaa bbb DIMENSIONS INCHES MILLIMETERS MIN NOM MAX MIN NOM MAX .031 .039 .002 .000 (.008) .007 .009 .011 .074 .079 .083 .042 .048 .052 .114 .118 .122 .020 BSC .012 .016 .020 10 .003 .004 0.80 1.00 0.00 0.05 (0.20) 0.18 0.23 0.30 1.87 2.02 2.12 1.06 1.21 1.31 2.90 3.00 3.10 0.50 BSC 0.30 0.40 0.50 10 0.08 0.10 E PIN 1 INDICATOR (LASER MARK) A aaa C C 1 LxN 2 A1 A2 C SEATING PLANE D N e bxN bbb CAB 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 POWER MANAGEMENT Land Pattern - MLP-10 PRELIMINARY K DIMENSIONS DIM C G H K P X Y Z INCHES (.112) .075 .055 .087 .020 .012 .037 .150 MILLIMETERS (2.85) 1.90 1.40 2.20 0.50 0.30 0.95 3.80 (C) H G Z Y X 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