AIC1580L

AIC1580/L Simple PWM Power Regulator with Shutdown FEATURES Operation Voltage up to 15V. Simple Voltage-Mode PWM Control. Fast Transient Response. 2V and 1.3V ± 2% Feedback Voltage Reference Option. Adjustable Current Limit without External Sense Resistors. 200KHz Free-Running Oscillator. Short-Circuit Protection with Low Short Circuit Output Current. Low Shutdown Current Built-in Soft Start. DESCRIPTION The AIC1580 is a high-power, high-efficiency voltage-mode switching regulator controller for motherboard VI/O power supply applications. Designed to drive a N-channel MOSFET in a standard buck topology, the AIC1580 features a high voltage CMOS output driver, short-circuit protection, and 8-pin package. An external 4-bit Digital-to-Analog Converter (DAC) can be used along with the AIC1580 to adjust the output voltage from 2.0V to 3.5V in 0.1V increments. Table 1 on the following page specifies the corresponding output voltage for 16 combinations of DAC inputs as in the typical application circuit. The 200KHz switching frequency allows for using small external components while maintaining high conversion efficiency. The 11MHz bandwidth and 6V/µS slew rate of the error amplifier ensures high converter bandwidth and fast transient response. The AIC1580 provides adjustable overcurrent and short-circuit protections by sensing the output current across the on resistance of the external N-channel MOSFET rather than an external low value sense resistor. The AIC1580L provides lower reference voltage (1.30V) than the default (2.00V, AIC1580) for lower VOUT requirement. APPLICATIONS Power Supply for Motherboard VGTL (1.5V Output) Power Supply for Motherboard VI/O. High-Power 5V to 3.xV DC/DC Regulators. Low-Voltage Distributed Power Supplies. Analog Integrations Corporation DS-1580-00 Sep 5, 00 4F, 9, Industry E. 9th Rd, Science Based Industrial Park, Hsinchu Taiwan, ROC TEL: 886-3-5772500 FAX: 886-3-5772510 www.analog.com.tw 1 AIC1580/L ORDERING INFORMATION AIC1580 XXX PACKAGE TYPE N: PLASTIC DIP S: SMALL OUTLINE TEMPERATURE RANGE C=0°C~+70°C REFERENCE VOLTAGE DEFAULT: 2.00V L: 1.30V ORDER NUMBER AIC1580CN AIC1580LCN (PLASTIC DIP) AIC1580CS AIC1580LCS (PLASTIC SO) PIN CONFIGURATION TOP VIEW OCSET 1 SD 2 COMP 3 FB* 4 *AIC1580: 2.00V AIC1580L: 1.30V 8 VCC 7 UGATE 6 PHASE 5 GND TYPICAL APPLICATION CIRCUIT *C1 MUST BE VERY CLOSE TO VCC PIN R1 C1 1U 10 12V L1 1.5U + 5V C9 1000P R2 2.2K AIC1580 CLSET VCC SD UDRI COMPPHASE FB GND M1 IR3303 R9 5K D1 C3 3000UF L2 7U + VOUT C7 C6 R6 33P 90.9K 1000P R7 VID0 VID1 VID2 6.04K R8 30.1K R4 15.0K R3 VID3 7.5K SRA1620 C4 6000UF R5 3.01K Switching Regulator for Pentium VCORE Supply 2 AIC1580/L Table 1. Output Voltage Program VID3 VID2 1 1 1 1 1 1 1 1 1 0 1 0 1 0 1 0 0 1 0 1 0 1 0 1 0 0 0 0 0 0 0 0 VID1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 VID0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 VOUT 2.00V 2.10V 2.20V 2.30V 2.40V 2.50V 2.60V 2.70V 2.80V 2.90V 3.00V 3.10V 3.20V 3.30V 3.40V 3.50V ABSOLUTE MAXIMUM RATINGS Supply Voltage, VCC ....…...………............................…………......................................... 15V Input, Output, or I/O Voltage ...............………………....……......... GND - 0.3V to VCC+0.3V ESD Classification .............................………….....……..............……......................... Class 2 Recommended Operating Conditions Supply Voltage, VCC ....…......................………….......……….................................. 12V ±10% Ambient Temperature Range .…................................………….……….................. 0°C~70°C Junction Temperature Range ....…............……….........…..……......................... 0°C~ 100°C Thermal Information Thermal Resistance, θJA (Typical, Note 1) SOIC Package ...............................………………………..……………........…. 100°C/W SOIC Package (with 3 in2 of Copper) ……………………………………......….. 90°C/W Maximum Junction Temperature (Plastic Package) ……….……..………................... 150°C Maximum Storage Temperature Range …………..…………......…….…......... –65°C~150°C Maximum Lead Temperature (Soldering 10 Sec) …………………...……......…......... 300°C Note 1: θJA is measured with the component mounted on an evaluation PC board in free air. TEST CIRCUIT Refer to TYPICAL APPLICATION CIRCUIT. 3 AIC1580/L ELECTRICAL CHARACTERISTICS specified.) PARAMETER VCC Supply Current Nominal Supply Power-On Reset VCC Threshold Oscillator Frequency Duty Cycle Internal Reference Voltage Reference Voltage Error Amplifier DC Gain Gain-Bandwidth Product Slew Rate Gate Driver Upper Gate Source Upper Gate Sink Protection OCSET Current Source SS Current Shutdown Shutdown Low Input Shutdown High Input Shutdown Mode Current VINL VINH 2 1 0.35 V V µA VOCSET =4.5VDC IOCSET ISS 200 10 µA µA RUGATE RUGATE 7 5 Ω Ω Comp=10pF GBW SR 76 11 6 dB MHz V/µS AIC1580 AIC1580L 1.96 1.27 2.00 1.30 2.04 1.33 V 200 88 KHz % VOCSET=4.5V 9.5 V UGATE Open IVCC 2 mA TEST CONDITIONS (VCC= 12V, Ta=25°C, unless otherwise SYMBOL MIN. TYP. M AX. UNIT 4 AIC1580/L TYPICAL PERFORMANCE CHARACTERISTICS Efficiency vs. Load Current 100 90 OCSET Current vs. Temperature 200 Vo=1.3V Vo=2.0V Vo=3.5V Efficiency (%) 80 70 60 50 40 Clset (µA) 198 196 Tc=134ppm/ C@ 0~100°C 194 192 30 1 2 3 4 IOUT (A) 5 6 7 8 9 10 11 -40 -20 0 20 Temperature (°C) 40 60 80 100 120 140 160 Over-Current Operation Output Clamped by Built-In Soft Start Transient Response 5 AIC1580/L BLOCK DIAGRAM Over Current + PHASE OCSET 200µA SD Power-On Reset Built-In Soft Start VCC REF FB COMP + Error AMP PWM Comparator + - Gate Control UGATE GND Oscilator PIN DESCRIPTIONS PIN 1: OCSET - Current limit sense pin. Connect a resistor ROCSET from this pin to the drain of the external MOSFET. ROCSET, an internal 200µA current source (IOCSET), and the external MOSFET onresistance (RDS(ON)) jointly set the overcurrent trip point according to the following equation: IPEAK = IOCSET × ROCSET RDS(ON) connected to FB pin to compensate the voltage-control feedback loop of the converter. PIN 4: FB The error amplifier inverting input pin. The FB pin and COMP pin are used to compensate the voltage-control feedback loop. Ground pin. Overcurrent detection pin. Connect the PHASE pin to source of the external NMOSFET. This pin detects the voltage drop across the MOSFET RDS(ON) for overcurrent protection. PIN 5: GNDPIN 6: PHASE- If FB pin voltage is sensed to be below 50% of the internal voltage reference VDAC, the overcurrent comparator cycles the soft-start function. PIN 2: SD - Shutdown pin. Connect this pin to ground for shutdown. PIN 7: UGATE- External MOSFET gate drive pin. Connect this pin to gate of the external MOSFET. PIN 8: VCC -The chip power supply pin. Recommended supply voltage is 12V. PIN 3: COMP - External compensation pin. This pin is connected to error amplifier output and PWM comparator. A RC network is 6 AIC1580/L APPLICATION CIRCUIT C9 1000P R2 2.2K R1 *C1 1 µF *C1 must be very close to VCC PIN + M1 R9 5K D1 SRA1620 IR3303 L2 7 µF + 10 12V L1 1.5µF C3 3000µF VOUT 1.5V/10A C4 6000µF 5V CLSET SD COMP FB VCC UDRI PHASE GND C7 R6 90.9K 33P C6 1000P AIC1580 R7 13K R5 2K PHYSICAL DIMENSIONS 8 LEAD PLASTIC SO (unit: mm) D SYMBOL A H E MIN 1.35 0.10 0.33 0.19 4.80 3.80 5.80 0.40 MAX 1.75 0.25 0.51 0.25 5.00 4.00 6.20 1.27 A1 B C D E e A C A1 e H L L 1.27(TYP) B 7 AIC1580/L 8 LEAD PLASTIC DIP (unit: mm) D SYMBOL A1 E1 MIN 0.381 2.92 0.35 0.20 9.01 7.62 6.09 — 2.92 MAX — 4.96 0.56 0.36 10.16 8.26 7.12 10.92 3.81 A2 b C E D E C A2 A1 L E1 e eB L 2.54 (TYP) eB b e 8