AIC1562

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