SC196 1.5A Synchronous Buck Converter with Integrated Power Devices POWER MANAGEMENT Description Features The SC196 is a synchronous step-down converter with integrated power devices designed for use in applications using a single-cell Li-ion battery. Its wide input voltage range also makes it suitable for use in systems with fixed 3.3V or 5V supply rails available. The switching frequency is nominally set to 1MHz, allowing the use of small inductors and capacitors. The current rating of the internal MOSFET switches allows a DC output current of 1.5A. The output voltage is set by connecting a resistor divider from the filter inductor to the feedback pin. See the SC196A for pin-programmable output voltages. The SC196 has a flexible clocking methodology that allows it to be synchronized to an external oscillator or controlled by the internal oscillator. The device operates 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. Up to 95% efficiency VOUT adjustable from less than 0.8V to VIN Output current — 1.5A Input range — 2.5V to 5.5V Quiescent current — 17μA Fixed 1MHz frequency or 750kHz to 1.25MHz synchronized operation PSAVE operation to maximize efficiency at light loads Shutdown current <1μA Fast transient response 100% duty cycle in dropout Soft-start Over-temperature and short-circuit protection Lead-free package — MLPD10-UT, 3 x 3 x 0.6 mm Applications 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. Cell phones Wireless communication chipset power Personal media players Microprocessor/DSP core/IO power PDAs and handheld computers WLAN peripherals USB powered modems 1 Li-Ion or 3 NiMH/NiCd powered devices Typical Application Circuit VIN CIN 10μF VOUT <0.8V to VIN 1.5A L1 4.7μH VIN 2.5V to 5.5V SC196 PVIN MODE LX VOUT ADJ RFB2 EN SYNC/PWM RFB1 CFB1 10pF COUT 22μF PGND GND February 8, 2007 1 www.semtech.com SC196 POWER MANAGEMENT PRELIMINARY Absolute Maximum Rating 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. Parameter Symbol Maximum Units Input Supply Voltage VIN -0.3 to 7 V Logic Inputs (N=SYNC/PWM, EN, MODE) VN -0.3 to VIN+0.3, 7V Max V Output Voltage VOUT -0.3 to VIN+0.3, 7V Max V ADJ Input VADJ -0.3 to VIN+0.3, 7V Max V LX Voltage VLX -1 to VIN +1, 7V Max V Thermal Impedance Junction to Ambient(1) θJA 40 °C/W VOUT Short-Circuit to GND tSC Continuous s Operating Ambient Temperature Range TA -40 to +85 °C Storage Temperature TS -65 to +150 °C Junction Temperature TJ -40 to +150 °C Peak IR Reflow Temperature TPKG 260 °C ESD Protection Level (2) VESD 2 kV Notes: (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, VOUT = 1.8V, EN = VIN, SYNC/PWM = VIN, MODE = VIN , TA = -40 to 85°C. Typical values are at TA = 25°C. Parameter Symbol Conditions Min Input Voltage Range VIN 2.5 UVLO Threshold (upper) VUVL 2.18 UVLO Hysteresis VUVLHYS 2.3 Max Units 5.5 V 2.45 V 150 0.8 mV VIN V 0.5 0.515 V IOUT = 0mA to 1.5A ±0.5 ±1 % SYNC/PWM=GND,COUT = 22μF, VIN = 2.5V to 5.5V, IOUT = 0mA to 1.5A ±2 ±3 % 2.8 3.57 A Output Voltage Range VOUT FB Voltage Tolerance VFB VIN = 2.5V to 5.5V, IOUT = 0mA to 1.5A Load Regulation (PWM) VOUT LOAD PSAVE Regulation VOUT PSAVE P-Channel Current Limit Typ 0.485 ILIM(P) VIN=2.5V to 5.5V Quiescent Current IQ SYNC/PWM = GND, IOUT = 0A, VOUT = 1.04 x VOUT(Programmed) 17 28 μA Shutdown Current ISD EN = GND, LX = OPEN 0.1 1 μA © 2007 Semtech Corp. 2 1.96 www.semtech.com SC196 POWER MANAGEMENT PRELIMINARY Electrical Characteristics (Cont.) Parameter Symbol Conditions Min Typ Max P-Channel On Resistance RDSP ILX = 100mA 0.275 Ω N-Channel On Resistance RDSN ILX = 100mA 0.165 Ω LX Leakage Current PMOS ILXP LX = GND, EN = GND 0.1 LX Leakage Current NMOS ILXN LX = 3.6V, EN = GND Oscillator Frequency 2 Units μA -2 0.1 fOSC 0.85 1.0 SYNC Frequency (upper) fSYNCU 1.25 SYNC Frequency (lower) fSYNCL 750 kHz Start-Up Time tSTART 5 ms Thermal Shutdown Thermal Shutdown Hysteresis μA 1.15 MHz MHz TSD 145 °C TSD-HYS 10 °C Logic Input High(1) VIH Logic Input Low(1) VIL Logic Input Current High(1) IIH -2 Logic Input Current Low(1) IIL -2 1.2 V 0.4 V 0.1 2 μA 0.1 2 μA Note: (1) For EN, SYNC/PWM, MODE © 2007 Semtech Corp. 3 www.semtech.com SC196 POWER MANAGEMENT PRELIMINARY Pin Configuration Ordering Information DEVICE PACKAGE SC196ULTRT(1)(2) MLPD-UT10 3x3x0.6 SC196EVB Evaluation Board Ordering Information PVIN 1 VIN 2 SYNC/PWM 3 EN 4 10 TOP VIEW 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. LX 9 PGND 8 GND 7 MODE 6 ADJ T VOUT 5 MLPD-UT: 3X3X0.6, 10 LEAD Marking Information 196 yyww xxxx yy = two digit year of manufacture ww = two digit week of manufacture xxxx = lot number © 2007 Semtech Corp. 4 www.semtech.com SC196 POWER MANAGEMENT PRELIMINARY Pin Descriptions Pin # Pin Name 1 PVIN 2 VIN 3 SYNC/PWM 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. 4 EN Enable digital input; a high input enables the SC196, a low disables and reduces quiescent current to less than 1μA. In shutdown, LX becomes high impedance. 5 VOUT Regulated output voltage sense pin — connect to the output capacitor allowing sensing of the output voltage. 6 ADJ Output Voltage Adjust and feedback compensation pin - connect resistor divider between this pin and GND to set the desired output voltage level. 7 MODE 8 GND 9 PGND 10 LX T THERMAL PAD © 2007 Semtech Corp. Pin Function Input supply voltage connection to switching FETs — connect the input capacitor between this pin and PGND directly. Input supply voltage for control circuits MODE select pin — MODE = VIN to select 100% duty cycle function, MODE = GND to disable this function. Ground Power Ground Inductor connection to the switching FETs Pad for heatsinking purposes — not connected internally. Connects to ground plane using multiple vias. 5 www.semtech.com SC196 POWER MANAGEMENT PRELIMINARY Block Diagram Plimit Amp 1 PVIN Current Amp EN 4 SYNC /PWM 3 OSC & Slope Generator Control Logic 10 LX PWM Comp 500mV Ref Error Amp PSAVE Comp MODE 7 VIN ADJ Nlimit Amp 9 PGND 2 6 © 2007 Semtech Corp. 6 8 GND 5 VOUT www.semtech.com SC196 POWER MANAGEMENT PRELIMINARY Applications Information SC196 Detailed Description The SC196 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. Table 1 — Recommended ADJ Resistor Combinations 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 external 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 SC196 has an internal synchronous NMOS rectifier and does not require a Schottky diode on the LX pin. Output Voltage Selection The output voltage can be programmed using a resistor network connected from VOUT to ADJ to GND. The combined resistance of the divider chain should be greater than 10KΩ and less than 1MΩ. Table 1 lists appropriate resistors which limit the bias current required of the external feedback resistor chain and ensuring good noise immunity. RFB1(kΩ) 1 200 200 1.1 200 240 1.2 200 280 1.3 200 320 1.5 178 357 1.6 200 442 1.7 178 432 1.8 178 464 1.875 178 487 2.5 200 806 2.8 178 820 3 178 887 3.3 100 560 3.6 100 620 3.8 100 665 Protection Features The SC196 provides the following protection features: · §R 0.5 u ¨¨ FB1 1¸¸ ¹ © RFB2 • Thermal Shutdown • Current Limit • Over-Voltage Protection • Soft-Start VOUT = output voltage (V) RFB1 = feedback resistor from VOUT to ADJ (Ω) RFB2 = feedback resistor from ADJ to GND (Ω) Thermal Shutdown The device has a thermal shutdown feature to protect the SC196 if the junction temperature exceeds 145°C. In thermal shutdown, the on-chip power devices are disabled, effectively tri-stating the LX output. Switching will resume when the temperature drops by 10°C. During this time, Resistors with 1% or better tolerance are recommended to ensure voltage accuracy. © 2007 Semtech Corp. RFB2(kΩ) Continuous Conduction & Oscillator Synchronization The SC196 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. The output voltage can be adjusted between less than 0.8V and VIN. The output voltage formula is: VOUT VOUT(V) 7 www.semtech.com SC196 POWER MANAGEMENT PRELIMINARY Applications Information (Cont.) if the output voltage decreases by more than 60% of its programmed value, a soft-start will be invoked. the output capacitor. The burst-to-off period in PSAVE will decrease as the load current reduces. 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, which causes the switching frequency to divide by a factor determined by the output voltage. This prevents the inductor current from "staircasing". 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 SC196 automatically detects when to exit PSAVE mode by monitoring VOUT . For the SC196 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. Over-Voltage Protection Over-voltage protection is provided on the SC196. In the event of an over-voltage on the output, the PWM drive is disabled, effectively tri-stating the LX output. The part will not resume switching until the output voltage has fallen 2% below the regulation voltage. If PSAVE operation is required, then a 22μF output capacitor must be used. 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 start-up. 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 through 1/8, 1/4, 1/2 and full internal oscillator frequency. The time at which these steps are made is controlled by the output voltage reaching predefined threshold levels. When the output voltage is within 2% of the regulation voltage, soft-start mode is disabled. BURST Higher Load Applied 1.5% 0.7% PSAVE Mode at Light Load PWM Mode at Medium/ High Load VOUT -2% Inductor Current Power Save Mode Operation The PSAVE mode may be selected by tying the SYNC/PWM pin to GND. Selecting PSAVE mode will enable the SC196 to automatically activate/deactivate operation at light loads, maximizing efficiency across the full load range. The SC196 automatically detects the load current at which it should enter PSAVE mode. The SC196 is optimized to track maximum efficiency with respect to VIN. 0A Time Figure 1 — Power Save Operation 100% Duty Cycle Operation The 100% duty cycle mode may be selected by connecting the MODE pin high. This will allow the SC196 to maintain output regulation under conditions of low input voltage/ high output voltage conditions. 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 © 2007 Semtech Corp. OFF 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 8 www.semtech.com SC196 POWER MANAGEMENT PRELIMINARY Applications Information (Cont.) 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: Table 1 — Recommended Inductors VOUT = VIN - IOUT x (RDSP + RIND) where VOUT = Output voltage VIN = Input voltage IOUT = Output current RDSP = PMOS switch ON resistance RIND = Series resistance of the inductor Inductor Selection The SC196 is designed for use with a 4.7μH inductor. Where VOUT > 3.8V is required, a 10μH inductor is recommended. The magnitude of the inductor current ripple depends on the inductor value and can be determined by the following equation: 'IL VOUT L u fosc Tolerance (%) Dimensions LxWxH (mm) BI Technologies HM66404R1 4.1 0.057 1.95 20 5.7 × 5.7 ×2.0 Coilcraft D01608C-472ML 4.7 0.09 1.5 20 6.6 × 4.5 × 3.0 TDK VLCF4020T- 4R7N1R2 4.7 0.098 1.24 30 4.0 × 4.0 × 2.0 Taiyo Yuden LMNP04SB4R7N 4.7 0.050 1.2 30 5.0 × 5.0 × 2.0 TOKO D52LC 4.7 0.087 1.14 20 5.0 × 5.0 × 2.0 Sumida CDRH3D16 4.7 0.050 1.2 30 3.8 × 3.8 × 1.8 Coilcraft LPS3015 4.7 0.2 1.1 20 3.0 × 3.0 × 1.5 fC 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: 1 2S L u COUT This filter has a single pole and 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. 'IL 2 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: Final inductor selection will depend on various design considerations such as efficiency, EMI, size and cost. Table 2 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 input voltage filtering, while a 22μF capacitor is recommended for improved input voltage filtering. © 2007 Semtech Corp. Rated Current (A) COUT Selection The internal compensation is designed to work with a certain output filter corner frequency defined by the equation: § VOUT · ¸ ¨¨1 VIN ¸¹ © IOUT(MAX) DCR (Ω) Note: recommended Inductors do not necessarily guarantee rated performance of the part. This equation demonstrates the relationship between input voltage, output voltage, and inductor ripple current. IL(PK) Value (μH) Manufacturer/Part # ΔVOUT(ESR) = ΔIL(RIPPLE) x ESRCOUNT Capacitors with X7R or X5R ceramic dielectric are strongly recommended for their low ESR and superior temperature 9 www.semtech.com SC196 POWER MANAGEMENT PRELIMINARY Applications Information (Cont.) and voltage characteristics. Y5V capacitors should not be used as their temperature coefficients make them unsuitable for this application. Attention should be paid to the DC voltage characteristics of the ceramic capacitors to be used for both input and output. Parts with different case sizes can vary significantly. For example a 22μF X5R 0805 capacitor with 3.6V DC applied could have a capacitance as low as 12μF. When a 1206 size part is used, the capacitance is approximately 20μF. Table 3 lists the manufacturers of recommended capacitor options. Table 3 — Recommended Capacitors Manufacturer/Part # Value (μF) Rated Voltage (VDC) Temperature Characteristic Case Size Murata GRM21BR60J226ME39L 22 6.3 X5R 0805 Murata GRM422X5R226 K16H533 22 16 X5R 1210 Murata GRM188R60J106 MKE19 10 6.3 X5R 0603 TDK C2012X5R0J106K 10 6.3 X5R 0603 Note: Where PSAVE operation is required, 22μF must be used for COUT. Feed-Forward Compensation Capacitor A small 10pf compensation capacitor, CFB1 is required to ensure correct operation. This capacitor should be connected directly across feedback resistor RFB1. Capacitors with X7R or X5R ceramic dielectric are strongly recommended for their superior temperature characteristics. © 2007 Semtech Corp. 10 www.semtech.com SC196 POWER MANAGEMENT PRELIMINARY Applications Information (Cont.) 2. Route the output voltage feedback path away from the inductor and LX node to minimize noise and magnetic interference. Keep RFB1 and RFB2 close to the ADJ pin to avoid noise pickup. 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. 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. GND VIN LOUT CIN LX VOUT COUT SYNC/PWM SC196 GND EN MODE CFB1 RFB2 RFB1 GND © 2007 Semtech Corp. 11 www.semtech.com SC196 POWER MANAGEMENT PRELIMINARY Typical Characteristics Efficiency vs. Load Current VOUT = 2.5V Efficiency vs. Load Current VOUT = 3.3V 100 RFB1+RFB2=10KΩ 100 VIN=3.9V PSAVE 90 VIN=3.3V PSAVE 90 80 80 70 70 VIN=3.2V PWM 60 VIN=4.2V PWM 50 VIN=4.2V PSAVE VIN=5.0V PWM VIN=5.0V PSAVE 40 Efficiency (%) Efficiency (%) RFB1+RFB2=10KΩ VIN=4.2V PWM 50 VIN=4.2V PSAVE 40 30 30 20 20 10 10 0 0.0001 0.001 0.01 IOUT(A) 0.1 1 VIN=3.3V PWM 60 0 0.0001 10 0.001 RFB1+RFB2=10KΩ 90 100 1 10 VIN=2.7V PSAVE 70 VIN=2.7V PWM Efficiency (%) Efficiency (%) 0.1 80 70 60 VIN=3.6V PWM VIN=3.6V PSAVE VIN=4.2V PWM VIN=4.2V PSAVE 40 60 VIN=3.6V PWM 20 20 10 10 0.001 0.01 IOUT(A) 0.1 1 VIN=4.2V PWM 0 0.0001 10 VIN=2.7V PWM VIN=4.2V PSAVE 40 30 0 0.0001 VIN=3.6V PSAVE 50 30 0.001 0.01 IOUT(A) 0.1 1 10 PWM to PSAVE Hysteresis Efficiency vs. Input Voltage 100 IOUT(A) RFB1+RFB2=10KΩ 90 VIN=2.7V PSAVE 80 50 0.01 Efficiency vs. Load Current VOUT = 1.0V Efficiency vs. Load Current VOUT = 1.8V 100 VIN=5.0V PWM VIN=5.0V PSAVE IOUT=750mA (PWM) / 50mA (PSAVE), RFB1+RFB2=10KΩ 1.82 VIN=3.6V, VOUT=1.8V VOUT=3.3V PWM 95 1.815 VOUT=3.3V PSAVE 85 VOUT=1.0V PWM VOUT(V) Efficiency (%) 90 80 1.805 VOUT=1.0V PSAVE 75 1.81 70 PSAVE Exit IOUT Increasing PSAVE Entry IOUT Decreasing 1.8 65 60 2.4 2.8 © 2007 Semtech Corp. 3.2 3.6 4.0 VIN(V) 4.4 4.8 5.2 1.795 0 5.6 0.1 0.2 0.3 0.4 0.5 0.6 IOUT(A) 12 www.semtech.com SC196 POWER MANAGEMENT PRELIMINARY Typical Characteristics (Cont.) Load Regulation VOUT vs. VIN 1.82 VOUT=1.8V, IOUT=750mA(PWM)/50mA(PSAVE) VIN=3.6V, VOUT=1.8V 1.82 PSAVE 1.815 1.81 PSAVE 1.81 VOUT(V) 1.8 VOUT(V) PWM 1.79 1.805 1.8 PWM 1.78 1.795 1.77 1.79 1.76 2.4 2.8 3.2 3.6 4 4.4 VIN(V) 4.8 5.2 5.6 1.785 6 0 0.2 0.4 VOUT vs. Temperature VOUT=1.8V 1.798 VIN=3.6V, VOUT=1.8V, IOUT=100mA 2 1.2 1.4 1.6 VIN=3.6V, VOUT=1.8V, PWM 1.6 PSAVE 1.792 1.4 1.79 1.2 VOUT(V) VOUT(V) 1 1.8 1.794 1.788 1 1.786 0.8 1.784 0.6 0.4 PWM 1.782 0.2 1.78 1.778 -60 0 -40 -20 0 20 TA(°C) 40 60 80 0 100 Quiescent Current vs. Input Voltage, PSAVE Mode 6 0.6 0.8 1 1.2 1.4 IOUT(A) 1.6 1.8 2 2.2 2.4 PWM Mode TA=-40°C 5.5 Quiescent current (mA) 20 19 TA=25°C 17 16 15 TA=-40°C 14 0.4 TA=85°C TA=85°C 18 0.2 Quiescent Current vs. Input Voltage, PWM Mode PSAVE Mode 21 Quiescent current (μA) 0.8 IOUT(A) Current Limit 1.796 22 0.6 TA=25°C 5 4.5 4 3.5 13 12 2.5 3 © 2007 Semtech Corp. 3.5 4 VIN(V) 4.5 5 5.5 3 2.5 6 13 3 3.5 4 VIN(V) 4.5 5 5.5 6 www.semtech.com SC196 POWER MANAGEMENT PRELIMINARY Typical Characteristics (Cont.) P-Channel RDSON vs. Input Voltage N-Channel RDSON vs. Input Voltage 0.40 0.22 0.35 0.20 TA=85°C 0.30 RDSON(Ω) RDSON(Ω) TA=85°C TA=25°C 0.25 0.18 TA=25°C 0.16 TA=-40°C 0.20 0.14 0.15 0.12 0.10 2.7 0.10 3.2 3.7 4.2 VIN(V) 4.7 5.2 TA=-40°C 2.7 Switching Frequency vs. Temperature 3.7 4.2 VIN(V) 4.7 5.2 100% Duty Cycle Mode VIN=3.4V, VOUT=3.3V, IOUT=150mA, PWM 1050 VIN=5.5V 1040 VIN=3.6V VOUT (20mV/div) 1030 Switching Frequency (kHz) 3.2 1020 1010 ILX (200mA/div) VIN=2.7V 1000 990 VLX (2V/div) 980 970 960 950 -50 -30 -10 10 30 50 70 90 110 Time (2μs/div) 130 TJ(°C) PSAVE Operation PWM Operation VIN=3.6V, VOUT=1.8V, IOUT=150mA, PWM VIN=3.6V, VOUT=1.8V, IOUT=150mA, PSAVE VOUT (50mV/div) VOUT (20mV/div) ILX (500mA/div) ILX (500mA/div) VLX (2V/div) VLX (5V/div) Time (1μs/div) Time (2μs/div) © 2007 Semtech Corp. 14 www.semtech.com SC196 POWER MANAGEMENT PRELIMINARY Typical Characteristics (Cont.) PSAVE Start-up PWM Start-up VIN=3.6V, VOUT=1.8V, IOUT=1.5A, PWM VIN=3.6V, VOUT=1.8V, IOUT=10mA, PSAVE VEN (5V/div) VEN (5V/div) VOUT (1V/div) VOUT (1V/div) IIN (500mA/div) IIN (100mA/div) Time (100μs/div) Time (1ms/div) Load Transient Response-1 Load Transient Response-2 VIN=3.6V, VOUT=1.8V, IOUT=100mA to 1.5A, PWM VIN=3.6V, VOUT=1.8V, IOUT=10mA to 1.5A, PWM VOUT (200mV/div) VOUT (200mV/div) IOUT (500mA/div) IOUT (500mA/div) Time (400μs/div) Time (400μs/div) Load Transient Response-3 Load Transient Response-4 VIN=3.6V, VOUT=1.8V, IOUT=100mA to 1.5A, PSAVE VIN=3.6V, VOUT=1.8V, IOUT=10mA to 1.5A, PSAVE VOUT (200mV/div) VOUT (200mV/div) IOUT (500mA/div) IOUT (500mA/div) Time (400μs/div) Time (400μs/div) © 2007 Semtech Corp. 15 www.semtech.com SC196 POWER MANAGEMENT PRELIMINARY Applications Circuits VOUT Programmed to 1.2V, no PSAVE VIN CIN 10μF VOUT 1.2V 1.5A L1 4.7μH VIN 2.5V to 5.5V SC196 PVIN MODE LX VOUT RFB1 280k 0.1% ADJ RFB2 200k 0.1% EN SYNC/PWM PGND CFB1 10pF COUT 10μF GND The output voltage is set at 1.2V by the selection of the two resistors RFB1 and RFB2, using resistor values from Table 1. PWM-only mode operation is selected by connecting the SYNC/PWM pin to the VIN pin. The 100% duty cycle capability is selected by connecting the MODE pin to the VIN pin. A 10μF capacitor is selected for the output, as PSAVE operation is not required in this application. © 2007 Semtech Corp. 16 www.semtech.com SC196 POWER MANAGEMENT PRELIMINARY Outline Drawing — MLPD-UT10 3x3x0.6 A E DIMENSIONS INCHES MILLIMETERS DIM MIN NOM MAX MIN NOM MAX B A A1 A2 b C D E e L N aaa bbb E PIN 1 INDICATOR (LASER MARK) A aaa C 1 .024 .002 .011 .083 .052 .122 .020 .60 0.05 (0.1524) 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 0.45 0.00 SEATING PLANE A1 C (.006) .007 .009 .074 .079 .042 .048 .114 .118 .020 BSC .012 .016 10 .003 .004 .018 .000 C A2 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. © 2007 Semtech Corp. 17 www.semtech.com SC196 POWER MANAGEMENT PRELIMINARY Land Pattern — MLPD-UT10 3x3x0.6 DIMENSIONS K (C) H G Z Y X DIM INCHES MILLIMETERS C G H K P X Y Z (.112) .075 .055 .087 .020 .012 .037 .150 (2.85) 1.90 1.40 2.20 0.50 0.30 0.95 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. 2. THERMAL VIAS IN THE LAND PATTERN OF THE EXPOSED PAD SHALL BE CONNECTED TO A SYSTEM GROUND PLANE. FAILURE TO DO SO MAY COMPROMISE THE THERMAL AND/OR FUNCTIONAL PERFORMANCE OF THE DEVICE 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 © 2007 Semtech Corp. 18 www.semtech.com