AIC1568 4-bit DAC, Simple PWM Power Regulator FEATURE DESCRIPTION Compatible with HIP6008. The AIC1568 is a high power, high efficiency Simple Voltage-Mode PWM Control. switching regulator controller optimized for high Fast Transient Response. performance microprocessor applications. It is 1.5% 4-Bit Digital-to-Analog Output Voltage. designed to drive an N-channel MOSFET in a Adjustable Current Limit without External Sense standard buck topology. Featuring a digitally Resistors. programmable switching regulator, the AIC1568 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. 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 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. regulation within 1.5% over temperature and line voltage shifts. The internal oscillator of the AIC1568 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/S slew rate, which enables high converter bandwidth for fast transient response. The AIC1568 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-1568-00 TEL: 886-3-5772500 FAX: 886-3-5772510 www.analog.com.tw 1 AIC1568 ORDERING INFORMATION AIC1568 XX PIN CONFIGURATION ORDER NUMBER AIC1568CS (PLASTIC SO) PACKAGE TYPE S: SMALL OUTLINE TOP VIEW 16 VSEN OCSET 1 15 RT/OVP SS 2 TEMPERATURE RANGE C: 0C~70C VID0 3 14 VCC VID1 4 13 BOOT VID2 5 12 UGATE VID3 6 11 PHASE 10 PGOOD COMP 7 9 GND FB 8 TYPICAL APPLICATION CIRCUIT C9 1000P 10 C2 0.1F 2.2K C8 0.1F JUMPER C7 VSEN OCSET RT/OVP SS VCC VID0 BOOT VID1 UDRI VID2 PHASE VID3 COMP PGOOD GND FB 90.9K 12V L1 RFP45N03L M1 VIN 1H 5V C3 1000F x 2 L2 2.0VVOUT3.5V at 10A 7H AIC1568 BYV118 R4 15K C6 1000P C1 1F + 33P R6 VDRI R1 R2 R5 D1 + C4 1000F x 6 R3 47K 3.01K R7 C5 1.2M 0.1F Switching Regulator for Pentium VCORE Supply 2 AIC1568 ABSOLUTE MAXIMUM RATINGS Supply Voltage, VCC .................................................................................................. 15V Boot Voltage, VBOOT .................................................................................................. 15V Input, Output, or I/O Voltage ................................................... GND - 0.3V to VCC+0.3V ESD Classification .............................................................................................. Class 2 Recommended Operating Conditions Supply Voltage, VCC ....................................................................................... 12V10% Ambient Temperature Range .......................................................................... 0C ~ 70C Junction Temperature Range ......................................................................... 0C ~100C Thermal Information Thermal Resistance, JA (Typical, Note 1) SOIC Package ..................................................................................... 100C/W SOIC Package (with 3 in2 of Copper) .................................................. 90C /W Maximum Junction Temperature (Plastic Package) ............................................. 150C Maximum Storage Temperature Range ................................................. -65C ~150C Maximum Lead Temperature (Soldering 10 Sec) ............................................... Note 1: JA 300C is measured with the component mounted on an evaluation PC board in free air. TEST CIRCUIT Refer to TYPICAL APPLICATION CIRCUIT. 3 AIC1568 ELECTRICAL CHARACTERISTICS PARAMETER (VCC= 12V, Ta=25C, unless otherwise specified.) 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 Oscillator Free Running Frequency RT Open 170 Total Variation 6K<RT<200K -20 Ramp Amplitude RT Open VOSC 200 230 KHz +20 % 1.5 VP-P DAC Output Voltage DAC Output Voltage Accuracy -1.5 +1.5 % Error Amplifier DC Gain 76 dB GBW 11 MHz SR 6 V/S Upper Gate Source RUGATE 8 12 Upper Gate Sink RUGATE 5.5 10 106 115 125 % IOCSET 170 200 230 A IOVP 30 Gain-Bandwidth Product Slew Rate Gate Driver Protection Over-Voltage Trip (VVSEN/VDAC) OCSET Current Source VOCSET =4.5VDC OVP Sourcing Current VVSEN =5.5V, VOVP=0V SS Current ISS SS Sink Current under VVSEN =VDAC, VOCSET=5.0V, Current Limit VPHASE=0V, VFB=VDAC - 50mV SS Sink Current under Hard VVSEN=0, VOCSET =5.0V, Current Limit VPHASE =0V, VFB=0V mA 10 A 130 A 65 mA 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 4 AIC1568 BLOCK DIAGRAM 115% + =- 110% VSEN 90% POWER-ON RESET OVP + =POWER GOOD PGOOD + - 50% - + + - 1A VCC OVER CURRENT SS OCSET IOCSET 200A 4V PHASE SOFT SATRT BOOT REFERENCE VID0 VID1 VID2 VID3 VDAC + + - + - 4BITS DAC ERROR AMP FB CONTROL LOGIC PWM COMPARATOR UGATE GND COMP RT/OVP OSCILLATOR 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 200 A current source (IOCSET), and the external MOSFET onresistance (RDS(ON)) jointly set the over current trip point according to the following equation: IPEAK = IOCSET x 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 - Soft start pin. Connect a capacitor from this pin to ground. An internal 10A current source provides soft start function for the converter. PIN 3: PIN 4: PIN 5: PIN 6: VID0 VID1 VID2 VID3 - 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. 5 AIC1568 Table 1. Output Voltage Program VID0 VID1 VID2 VID3 VDAC 0 0 0 0 3.5V 1 0 0 0 3.4V 0 1 0 0 3.3V 1 1 0 0 3.2V 0 0 1 0 3.1V 1 0 1 0 3.0V 0 1 1 0 2.9V 1 1 1 0 2.8V 0 0 0 1 2.7V 1 0 0 1 2.6V 0 1 0 1 2.5V 1 1 0 1 2.4V 0 0 1 1 2.3V 1 0 1 1 2.2V 0 1 1 1 2.1V 1 1 1 1 2.0V 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 PIN 9: GND - The error amplifier inverting input pin. The FB pin and COMP pin are used to compensate the voltage-control feedback loop. - Signal GND. It also serves as the power GND for the upper gate driver. PIN 10: 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. the PHASE pin to source of the external MOSFET. This pin detects the voltage drop across the MOSFET RDS(ON) for over-current protection. PIN 12: UGATE- External MOSFET gate drive pin. Connect this pin to gate of the external MOSFET. PIN 13: BOOT - External MOSFET driver power supply pin. To convert 5V main power to VCORE power by driving N-channel MOSFET, supply voltage of no higher than 12V is recommended since the negative power terminal of the internal driver is internally tied to GND. PIN 14: VCC - The chip power supply pin. Recommended supply voltage is 12V. PIN 15: RT/OVP- Frequency adjustment and overvoltage indicator pin. This pin is multiplexed to provide two functions. The first function is oscillator switching frequency adjustment. Connecting a resistor (RT) from this pin to GND increases the frequency according to the following equation: FS 2 0 0 K H z + 5 x 105 lo g RT The second function for this pin is to drive an external SCR in the event of an over voltage fault. PIN 16: VSEN - Converter output voltage sense pin. Connect this pin to the converter output. The PGOOD and OVP comparator circuits use this signal to report output voltage status and perform overvoltage protection function. PIN 11: PHASE - Over current detection pin. Connect 6 AIC1568 PHYSICAL DIMENSION 16 LEAD PLASTIC SO (150 mil) (unit: mm) D E H SYMBOL MIN MAX A 1.35 1.75 A1 0.10 0.25 B 0.33 0.51 C 0.19 0.25 D 9.80 10.00 E 3.80 4.00 e e A 1.27 (TYP) H 5.80 6.20 L 0.40 1.27 A1 B C L 7