FA7611CP(E) FA7611CP(E) Bipolar IC For Switching Power Supply Control ■ Description ■ Dimensions, mm The FA7611CP(E) is a bipolar IC containing basic circuit necessary for PWM-type switching power supply control. Á SSOP-16 0.65 2.1max +0.1 8 6.2 0.3 0.2 –0.05 1 0~10˚ ■ Applications 5.3 7.9±0.3 • Low-voltage operation (VCC = 3.6 to 22V) • Predrivers: Totem-pole output or open-collector for CH1 and open-collector output for CH2 • Latch-mode short-circuit protection function (no malfunction due to electrical noise) • soft-start function • Undervoltage lock-out function • One capacitor shared for short circuit protection and for soft start to minimize the number of external discrete components 9 16 0.1±0.1 ■ Features 0.6 • Battery power supply for portable equipment Á DIP-16 16 6.5 9 8 19.4 1.5 0.2min 3.4 0.81 0.5±0.1 2.54±0.25 ■ Block diagram +0.1 5 .0 0.3 –0 7.6 0~15 ˚ 5˚ 0~1 Pin No. Pin symbol Description 1 CT CS Oscillator timing capacitor DT2 IN2 (+) Dead time adjustment IN2 (–) FB2 GND OUT2 VCC Inverting input to error amplifier OUT1R OUT1 FB1 IN1 (–) IN1 (+) CH. 1 Current limiting resistor DT1 REF Dead time adjustment 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1 3.1min 4.3max 1 Capacitor for soft-start, shortcircuit protection and delay Non-inverting input to error amplifier Error amplifier output Ground CH. 2 Output Power supply CH. 1 Output Error amplifier output Inverting input to error amplifier Non-inverting input to error amplifier Reference voltage (0.5V) Reference voltage output (2.5V) FA7611CP(E) ■ Absolute maximum ratings ■ Recommended operating conditions Item Symbol Rating Unit Item Symbol Min. Max. Unit Supply voltage VCC IOR IO Pd 22 V Supply voltage 3.6 20 V 5 mA Feedback resistance ±50 mA Oscillator timing capacitor 400 mW Oscillator timing resistance VCC RNF CT RT Topr Tstg –20 to +85 °C Oscillation frequency fOSC –40 to +150 °C Reference voltage output current Output current Total power dissipation Operating temperature Storage temperature 100 kΩ 220 22,000 pF 10 100 kΩ 5 200 kHz ■ Electrical characteristics (Ta = 25°C, VCC = 6V, RT = 33kΩ, CT = 1000pF) Reference voltage section Item Symbol Test condition Output voltage VREF LINE LOAD VTC1 IOR = 1mA 2.425 VCC = 3.6 to 20V, IOR =1mA IOR = 0.1 to 1mA Ta = –20 to +25°C VTC2 Ta = +25 to +85°C Item Symbol Test condition Min. Oscillation frequency CT = 1000pF, RT = 33kΩ VCC = 3.6 to 20V 95 Frequency variation 1 (due to supply voltage change) fOSC fdV Frequency variation 2 (due to temperature change) fdT Ta = –20 to +85°C Item Symbol Test condition Reference voltage VB Input bias current IB AV GB VOM+ VOM– Line regulation Load regulation Output voltage variation due to temperature change Min. Typ. Max. Unit 2.475 2.525 V 4 12 mV 1 6 mV –1 1 % –1 1 % Typ. Max. Unit 115 135 kHz Oscillator section 1 % 5 % Error amplifier section Open-loop voltage gain Unity-gain bandwidth Maximum output voltage (Pin 6 and Pin 12) Min. Typ. Max. Unit 0.484 0.494 0.504 V 5 100 70 0.6 RNF = 100kΩ MHz VREF–0.2 V RNF = 100kΩ 200 mV 200 µA Unit IOM+ VOM = 1V 40 Item Symbol Test condition Min. Typ. Max. Input threshold voltage (Pin 6 and Pin 12) VTH0 VTH50 Duty cycle = 0% 0.85 0.95 Duty cycle = 50% 1.1 Output source current (Pin 6 and Pin 12) nA dB 85 PWM comparator section Input threshold voltage (Pin 6 and Pin 12) V V 2 FA7611CP(E) Dead time adjustment circuit section Item Symbol Input bias current (Pin 3 and Pin 15) IBDT VTH DT0 VTH DT50 Item Symbol Test condition Input threshold voltage (Pin 6 and Pin 12) VTH PC ICHG VTH LA Pin 2 = 0V, Pin 6, Pin 12 = 2V 10 Item Symbol Test condition OFF-to-ON threshold voltage VTH ON VTH OFF VHYS Input threshold voltage (Pin 3 and Pin 15) Input threshold voltage (Pin 3 and Pin 15) Test condition Min. Typ. Max. Unit 80 300 nA Duty cycle = 0% 0.22 0.32 Duty cycle = 50% 0.46 V V Short-circuit protection circuit section Charge current (Pin 2) Latch-mode threshold voltage (Pin 2) Min. Typ. Max. Unit 1.20 1.50 1.80 V 30 50 µA 1.20 1.50 1.80 V Min. Typ. Max. Unit Undervoltage lockout circuit section ON-to-OFF threshold voltage Voltage hysteresis 2.65 V 2.60 V 50 mV Output section Item Symbol Test condition Min. CH. 1 H-level output voltage (Pin 11) V01H V01L ISOURCE1 RL = 10kΩ 3.5 CH. 1 L-level output voltage (Pin 11) CH. 1 Output source current (Pin11) Output sink current = 20mA ROUT1 = 470Ω Typ. 4.0 0.25 8 Max. Unit V 0.65 11 V mA (Pin 11) = 0V V02L Output sink current = 20mA Item Symbol Test condition Supply current ICC LA ICC AV Latch mode RL = ∞ Duty cycle = 50% 3.5 CH. 2 L-level output voltage (Pin 8) 1.0 1.5 V Typ. Max. Unit 2.0 3.0 mA 6.0 mA Overall device Operating-state supply current 3 Min. FA7611CP(E) ■ Characteristic curves (Ta = 25°C) Oscillation frequency (fOSC ) vs. timing capacitor capacitance (C T) Output duty cycle vs. CS terminal voltage (VCS ) Output duty cycle vs. DT terminal voltage (VDT) Output duty cycle vs. FB terminal voltage (VFB) CH-1 output source current (ISOURCE1) vs. supply voltage (VCC ) L-level output voltage (VO1L ) vs. CH. 1 output sink current (ISINK1 ) 4 FA7611CP(E) L-level output voltage (VO2L) vs. CH. 2 output sink current (ISINK2) Supply current (ICC) vs. supply voltage(VCC) Operating-state supply current (ICCAV) vs. oscillation frequency (fOSC) Phase θ [deg] Error amplifie frequency (f) vs. valtage gain (AV) / phase (θ) 5 FA7611CP(E) ■ Application circuit Á Flyback-transformer type and chopper type buck converter circuit Flyback 24V TR VCC 3.3k + – C1 63.5k D10 + – C11 D11 + – C12 D12 – + C13 10V 1k 100k Q1 22k –10V 0.01µ 22000p Rout1 1M 16 15 14 13 12 11 10 9 REF DT1 IN1(+) IN1(–) FB1 OUT1 OUT1R VCC VCC + – C2 FA7611CP(E) CT CS 1 2 DT2 IN2(+)IN2(–) FB2 3 4 5 GND OUT2 6 7 8 L2 1M Buck 5V Q2 R21 4.7µ 56k 1000p R20 0.01µ D20 330k + – C20 1k 820k 2.2k 20.07k Á Chopper type buck converter and inverting converter circuit 3.3k 30.1k L1 1k 0.01µ Buck 5V Q1 R11 Rout1 + – C10 22000p D10 VCC 16 15 REF DT1 14 IN1(+) 13 IN1(–) 12 FB1 11 OUT1 10 OUT1R + – C1 9 VCC VCC FA7611CP(E) CT CS DT2 IN2(+) IN2(–) FB2 GND OUT2 1 2 3 4 5 6 7 8 + – C2 R21 R20 Q2 56k 330k 1000p D20 + 4.7µ – Inverting –5V 47000p L2 820k – + C20 1k 100k 2.2k 22k 5.02k Parts tolerances characteristics are not defined in the circuit design Please connect a capacitor, which the value is about 0.01 µF to 0.1µF, sample shown above. between VCC and REF terminals in order to prevent from irregular When designing an actual circuit for a product, you must determine output pulse at start-up. parts tolerances and characteristics for safe and economical operation. 6