AIC1562 High-Efficiency, Bootstrapped DC/DC Converter FEATURES DESCRIPTION 3V to 20V Input Voltage Operation. The AIC1562 is a high performance monolithic Internal 800mA Switch. DC/DC Bootstrapped Driver for N-Channel MOSFET. bootstrapping capability, designed specifically for High Efficiency (up to 90%). driving N-channel MOSFET to achieve maximum Fast Transient Response. possible power conversion efficiency. The device Internal ±2% Reference. consists of an internal temperature compensated Low Quiescent Current at 1.6mA. reference, Frequency Operation from 200Hz to 200KHz. oscillator, bootstrapped driver and a 800mA output converter drive comparator, IC with controlled output- duty cycle switch. Working with the AIC1741, a low power APPLICATIONS adjustable regulator, the AIC1562 works at 100% CPU Power Supplies for Mother Boards. duty cycle under heavy load transient conditions to DC/DC Converters for CPU VRMs. minimize transient response time, making it an idea Step-Down DC-DC Converter Module. precision switching power solution to stringent requirements on computer mother boards. TYPICAL APPLICATION CIRCUIT C3 + AIC1562 TC VCC GND FB C1 47µF R1 1K Q2 C2 220pF R8 10K C11, C12: Ceramic Capacitor L1: Iron Powder Core VOUT= (1+R10/1K)x1.235V C4 D1 VOUT : 2.5V~3.5V/10A L1 + Z1 5.1V VIN FB GND VOUT AIC1741 5V 1000µF/6.3Vx2 C8, C9 7.5µF 0.022µF R2 24K + 1000µF 12V SE MTD20N03DH Q1 SC 2N2907A D3 BST VIN 1N4148 BYV118 0.1µF D2 1N4148 C10 C11 C12 0.1µF 0.1µF 1000µF/6.3V x2 x2 x5 + C13 P5 MICROPROCESSOR CPU R10 R8 R7 C5 470 0.1µF 1K R9 1K CPU Power Supply for P5 Mother Board Analog Integrations Corporation 4F, 9, Industry E. 9th Rd, Science Based Industrial Park, Hsinchu Taiwan, ROC DS-1562-00 TEL: 886-3-5772500 Jan 30, 01 FAX: 886-3-5772510 www.analog.com.tw 1 AIC1562 ORDERING INFORMATION AIC1562 XX ORDER NUMBER PACKAGE TYPE N: PLASTIC DIP S: SMALL OUTLINE AIC1562CN (PLASTIC DIP) TEMPERATURE C: 0°C~+70°C AIC1562CS (PLASTIC SO) PIN CONFIGURATION TOP VIEW SC 1 8 BST SE 2 7 NC TC 3 GND 4 6 VCC 5 FB ABSOLUTE MAXIMUM RATINGS Supply Voltage ...............................................…………………....................................... 20V Comparator Input Voltage Range .........................…………….............................. -0.3V~20V Switch Collector Voltage Switch Emitter Voltage ....................................………………...................................... 20V ......................................…………………................................... 20V Switch Collector to Emitter Voltage Driver Collector Voltage .......................……………..................................... 20V .....................................………………..................................... 20V Switch Current ...............................................................…...………………........…........... 1A Power Dissipation and Thermal Characteristics DIP Package Ta= 25°C ................................…………........................... 1.0W Thermal Resistance ..........………............................... 100°C/W SO Package Ta= 25°C ...........................……………......................... 625mW Thermal Resistance ...............……….......................... 160°C/W Operating Junction Temperature .............................…………................................... 125°C Operating Ambient Temperature Range ...................…………............................ 0°C~70°C Storage Temperature Range..................…………….................................. - 65°C ~ 150°C TEST CIRCUIT 2 AIC1562 R1 1K VCC 40mA Current Source 0.8A Current Source 1 2 3 2V/0V IDISCHARG/ ICHG 4 SC BST SE NC TC VCC GND AIC1562 CT FB 8 7 6 5 VCC 1.275V 1.225V 1nF 3 AIC1562 ELECTRICAL CHARACTERISTICS (VCC= 5V, Ta=25°°C unless otherwise specified.) PARAMETER TEST CONDITIONS SYMBOL MIN. TYP. MAX. UNIT ICHG 15 25 35 A IDISCHG 120 150 180 µA Oscillator Charging Current 5.0V≤VCC≤20V Discharge Current 5.0≤VCC≤20V Voltage Swing PIN 3 Discharge to Charge Current Ratio VIS =VCC VOSC 0.6 IDISCHG / ICHG 6.0 V Output Switch Saturation Voltage, Emitter Follower Connection ISE=0.8A; VBST =VSC = VCC VCE(SAT) 1.6 2.0 V Saturation Voltage ISC=0.8A; IBST =40mA, (Forced ≅20) VCE (SAT) 0.5 0.8 V DC Current Gain ISC =0.8A; VCE=5.0V Collector Off-State Current VCE=20V IC(OFF) Ta=25°C VFB hFE 35 120 10 nA Comparactor Threshold Voltage 0°C ≤Ta ≤70°C Threshold Voltage Line Regulation 3.0V ≤VCC≤20V Input Bias Current Supply current 1.225 1.25 1.21 1.275 V 1.29 V mV/V REGLINE 0.1 0.5 VIN=0V IIB 0.4 2 µA VIS =VCC, pin 5>VFB 5.0V ≤VCC≤20V CT=1nF PIN 2=GND Remaining pins open ICC 1.6 3 mA 4 AIC1562 TYPICAL PERFORMANCE CHARACTERISTICS Standby Supply Current vs. Supply Voltage ICC Supply Current (mA) 1000 2 VCC=5V VIPK=VCC PIN 5=GND 100 ON TIME 10 OFF TIME 1 tON-OFF Output Switch ON-OFF Time (µS) Output Switch ON-OFF Time vs. Oscillator Timing Capacitor 1 0.1 10 1.8 0.8 0.4 0 100 CT=1nF VIS=VCC PIN 2=GND 1.2 0 5 CT, Oscillator Timing Capacitor (nF) 15 20 Emitter Follower Configuration Output Switch Saturation Voltage vs. Emitter Current VFB, Threshold Voltage vs Temperature 1.3 1.8 VCE(SAT), Saturation Voltage (V) VFB,, Threshold Voltage (V) VCC=5V CT=1nF PIN 2=GND 1.28 1.26 1.24 1.22 1.2 10 VCC, Supply Voltage (V) 10 0 20 30 40 50 60 70 80 Temperature (°C) VCC=5V PIN 1, 7, 8= VCC PIN 3, 5= GND 1.6 1.4 1.2 0 0.2 0.4 0.6 0.8 1 IE, Emitter Current Current (A) Common Emitter Configuration Output Switch Saturation Voltage vs. Collector Current VCE(SAT), Saturation Voltage (V) 0.6 VCC=5V PIN 7=VCC PIN 2, 3, 5=GND 0.4 0.2 Forced Beta = 20 0 0 0.2 0.4 0.6 0.8 1 Temperature (°C) 5 AIC1562 BLOCK DIAGRAM 1 SC 8 Q2 BST QS Q1 R 80 2 SE 7 NC Is CT Oscillator TC 6 3 Comparator 1.25V Reference Voltage GND 4 VCC + - 5 FB PIN DESCRIPTIONS PIN 1: SC - 0.8A switch collector. PIN 2: SE - Darlington switch emitter. PIN 3: TC - Oscillator timing capacitor. PIN 4: GND - Power ground. PIN 5: FB - Feedback comparator inverting input. PIN 6: VCC - Power supply input. PIN 7: NC - PIN 8: BST - Bootstrapped driver collector. 6 AIC1562 PHYSICAL DIMENSIONS 8 LEAD PLASTIC SO (unit: mm) D SYMBOL MIN MAX A 1.35 1.75 A1 0.10 0.25 B 0.33 0.51 C 0.19 0.25 D 4.80 5.00 E 3.80 4.00 H E e e A A1 C B 1.27(TYP) H 5.80 6.20 L 0.40 1.27 L 8 LEAD PLASTIC DIP (unit: mm) D E1 E A2 A1 C L eB b e SYMBOL MIN MAX A1 0.381 — A2 2.92 4.96 b 0.35 0.56 C 0.20 0.36 D 9.01 10.16 E 7.62 8.26 E1 6.09 7.12 e 2.54 (TYP) eB — 10.92 L 2.92 3.81 7