AIC1566 4-bit DAC, Simple PWM Power Regulator With Linear Controller FEATURES DESCRIPTION Switching Regulator and Low Dropout Linear The AIC1566 is a high power, high efficiency Regulator on Single Chip. switching regulator controller optimized for high Simple Voltage-Mode PWM Control. performance microprocessor applications. It is Fast Transient Response. designed to drive an N-channel MOSFET in a ±1.5% 4-Bit Digital-to-Analog Output Voltage. standard buck topology. Featuring a low Adjustable Current Limit Without External Sense dropout and Resistors. programmable switching regulator, the AIC1566 Full 0% to 100% Duty Ratio. includes monitoring and protection capabilities in 200KHz Free-Running Oscillator Programmable addition to all the essential PWM control up to 350KHz. functions. linear regulator a digitally Power-Good Output Voltage Monitor. Short Circuit Protection with Low Short Circuit The internal 4-bit Digital-to-Analog Converter Output Current. (DAC) adjusts the output voltage from 2.0V to 3.5V in 0.1V increments. The precision reference and voltage-mode control can provide output APPLICATIONS regulation within ±1.5% over temperature and line Power Supply for Pentium, Pentium Pro, Power PC, and Alpha Microprocessors. High-Power 5V to 3.xV DC/DC Regulators. Low-Voltage Distributed Power Supplies. voltage shifts. The internal oscillator of the AIC1566 free runs at 200KHz and can be adjusted up to 350KHz. The resulting PWM duty ratio ranges from 0% to 100%. The error amplifier features a 11MHz bandwidth and 6V/µS slew rate which enables converter bandwidth for fast high transient performance. The AIC1566 provides adjustable over current and short circuit protections. It senses the output current across the on resistance of the N-channel MOSFET without an external low value sense resistor. It also monitors the output voltage with a window comparator and issues a power good signal when the output is within 10% of the rated output voltage. Analog Integrations Corporation 4F, 9, Industry E. 9th Rd, Science Based Industrial Park, Hsinchu Taiwan, ROC DS-1566-00 TEL: 886-3-5772500 FAX: 886-3-5772510 www.analog.com.tw 1 AIC1566 ORDERING INFORMATION AIC1566 XX PIN CONFIGURATION ORDER NUMBER TOP VIEW PACKAGE TYPE S: SMALL OUTLINE AIC1566CS (PLASTIC SO) OCSET 1 20 VSEN SS 2 TEMPERATURE RANGE C: 0°C~70°C 19 RT/OVP VID0 3 18 VCC VID1 4 17 BOOT VID2 5 16 UGATE VID3 6 15 PHASE COMP 7 14 PGOOD FB 8 12 LIDRI CLN 10 11 VLFB TYPICAL APPLICATION CIRCUIT C9 1000pF R1 10 R2 C8 C1 1µF L1 5V 33pF C6 1000pF 137 1% 1µH C3 1000µF x 2 M1 VCORE L2 5V FD3055 AIC1566 R11 + RFP45N03L PHASE VID3 COMP PGOOD FB GND CLP+ LIDRI VLFB CLN C7 90.9K C2 0.1µF OCSET VSEN RT/OVP SS VCC VID0 BOOT VID1 UGATE VID2 0.1µF R6 12V 2.2K BYV118 D1 13 GND CLP 9 VI/O 3.3V 10A R10 237 1% + C10 1000µF R4 15K R3 7µH 10A + C4 1000µF x 6 47K R5 3.01K C5 R12 1.2M 0.1µF Pentium Pro VCORE and VI/O Power Supply 2 AIC1566 ABSOLUTE MAXIMUM RATINGS Supply Voltage, VCC ....…..............………………............................................................. 15V ……….........................……………................................................ 15V Boot Voltage, VBOOT 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. ELECTRICAL CHARACTERISTICS (VCC= 12V, Ta=25°°C, unless otherwise specified.) PARAMETER TEST CONDITIONS SYMBOL MIN. TYP. MAX. UNIT VCC Supply Current Nominal Supply UGATE Open IVCC 2 mA Power-On Reset VCC Threshold VOCSET=4.5V 7 Rising VOCSET Threshold 8.5 1.26 V V Reference and DAC DACOUT Voltage Accuracy -1.5 +1.5 % 230 KHz +20 % Oscillator Free Running Frequency RT Open 170 Total Variation 6K≤RT≤200KΩ -20 Ramp Amplitude RT Open ∆VOSC 200 1.5 VP-P 3 AIC1566 ELECTRICAL CHARACTERISTICS (Continued) PARAMETER TEST CONDITIONS SYMBOL MIN. TYP. MAX. UNIT Error Amplifier DC Gain 76 dB GBW 11 MHz SR 6 V/µS Upper Gate Source RUGATE 8 12 Ω Upper Gate Sink RUGATE 5.5 10 Ω 106 115 125 % IOCSET 170 200 230 µA IOVP 30 Gain-Bandwidth Product Slew Rate Gate Driver Protection Over-Voltage Trip (VVSEN / VVDAC) OCSET Current Source VOCSET=4.5VDC OVP Sourcing Current VVSEN =5.5V, VOVP=0V SS Current SS Sink Current under Current Limit ISS VVSEN=VDAC, VOCSET=5.0V, VPHASE=0V mA 10 µA 130 µA 65 mA VFB=VDAC-50mA SS Sink Current under Hard Current Limit VVSEN =0, VOCSET =5.0V, VPHASE =0V, VFB=0V Power Good Upper Threshold (VVSEN / VDAC) VVSEN Rising 106 114 % Lower Threshold (VVSEN / VDAC) VVSEN Falling 84 94 % Hysteresis (VVSEN / VDAC) Upper and Lower Threshold PGOOD Voltage Low IPGOOD=5mA VPGOOD 2 % 0.5 V Linear Regulator VLFB Feedback Voltage Hysteresis (VVSEN/VDAC) 1.18 VLFB Bias Current 1.21 1.24 40 LIDRI Sourcing Current 10 CLP, CLN, Current Limiting Threshold 10 V nA mA 20 30 mV 4 AIC1566 BLOCK DIAGRAM 115% POWER-ON RESET + VCC OVP 110% + VSEN 90% + PGOOD POWER GOOD 50% OCSET + - + 10µA - OVER CURRENT 200µA SS 4V PHASE SOFT START BOOT VID0 VID1 VID2 VID3 VDAC 4BITS DAC + ERROR AMP CONTROL LOGIC + + PWM COMPARATOR GND REFERENCE OSCILLATOR FB COMP 1.2V LINEAR AMP. + CLP CLN UGATE - + 20mV - + - CURRENT SENSE AMP. RT/OVP LIDRI VLFB 5 AIC1566 PIN DESCRIPTION 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 over current trip point according to the following equation: IPEAK = IOCSET × ROCSET RDS(ON) If FB pin voltage is sensed to be below 50% of the internal voltage reference VDAC, the over current comparator cycles the soft-start function. PIN 2: SS PIN 3: VID0 PIN 4: VID1 PIN 5: VID2 PIN 6: VID3 - Soft start pin. Connect a capacitor from this pin to ground. An internal 10µA current source provides soft start function for the converter. - 4-bit DAC voltage select pin. TTL inputs used to set the internal voltage reference VDAC. When left open, these pins are internally pulled up to 5V and provide logic ones. The level of VDAC sets the converter output voltage as well as the PGOOD and OVP thresholds. Table 1 specifies the VDAC voltage for the 16 combinations of DAC inputs. PIN 7: COMP - External compensation pin. This pin is connected to error amplifier output and PWM comparator. An RC network is connected to FB pin to compensate the voltage-control feedback loop of the converter. PIN 8: FB - The error amplifier inverting input pin. The FB pin and COMP pin are used to compensate the voltage-control feedback loop. Table 1. Output Voltage Program VID3 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 VID2 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 VID1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 VID0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 VDAC 3.5V 3.4V 3.3V 3.2V 3.1V 3.0V 2.9V 2.8V 2.7V 2.6V 2.5V 2.4V 2.3V 2.2V 2.1V 2.0V PIN 9: CLP - Linear regulator current sense pin. This pin is the positive input of the current sense comparator. PIN 10: CLN - Linear regulator current sense pin. This pin is the negative input of the current sense comparator. PIN 11: VLFB - Negative feedback pin for the linear regulator error amplifier. PIN 12: LIDRI - Linear regulator output drive pin. This pin can drive either a Darlington NPN or an Nchannel MOSFET. PIN 13: GND - Signal GND. It also serves as the power GND for the upper gate driver. PIN 14: PGOOD-Power good indicator pin. PGOOD is an open drain output. This pin is pulled low when the converter output is 10% out of the VDAC reference voltage. PIN 15: PHASE - Over current detection pin. Connect the PHASE pin to source of the external MOSFET. This pin detects the voltage drop across the MOSFET RDS(ON) for over- 6 AIC1566 current protection. PHYSICAL DIMENSIONS 20 LEAD PLASTIC SO (300 mil) (unit: mm) D H E e B SYMBOL MIN MAX A 2.35 2.65 A1 0.10 0.30 B 0.33 0.51 C 0.23 0.32 D 12.60 13.00 E 7.40 7.60 e A A1 C L 1.27(TYP) H 10.00 10.65 L 0.40 1.27 7