Bipolar IC FA7610CP(N)/12CP(N)/17CP(N)FA7610CP(N)/FA7612CP(N)/FA7617CP(N) For Switching Power Supply Control ■ Description ■ Dimensions, mm The FA7610CP(N), 7612CP(N) and 7617CP(N) are bipolar ICs containing basic circuits necessary for PWM-type switching power supply control. To minimize the number of external discrete components, the FA7610CP(N) is provided for a flyback or step-up powersupply circuit, the FA7612CP(N) for a step-down power-supply circuit and FA7617CP(N) for a flyback power supply circuit. Á SOP-8 4 1 0.4±0.1 1.27±0.2 0~8° 0.20 1.7max +0.1 –0.05 4.9 Á DIP-8 5 6.5 8 1 9.3 4 2.54±0.25 0.5±0.1 3.0min 4.5max 1.5 3.4 FA7612CP(N) • For step-down power-supply circuit (maximum output duty = up to 100%) • Open collector output • PWM-type switching power supply control • Low-voltage operation (VCC = 3.6 to 22V) • Latch-mode short-circuit protection function (no malfunction by noise) • Soft-start function • Undervoltage lockout function • One capacitor shared for short circuit protection and for softstart to minimize the number of external discrete components 6.0±0.2 3.9 ■ Features FA7610CP(N) • For flyback transformer-type or step-up power-supply circuit (maximum output duty = 64% typical) • Totem-pole predriver • PWM-type switching power supply control • Low-voltage operation (VCC = 3.6 to 22V) • Latch-mode short-circuit protection function (no malfunction by noise) • Soft-start function • Undervoltage lockout function • One capacitor shared for short circuit protection and for softstart to minimize the number of external discrete components 5 8 0.3 +0.1 5 –0.0 7.6 0~15 ˚ 5˚ 0~1 FA7617CP(N) • For flyback transformer-type power-supply circuit (maximum output duty = 67% typical) • Open collector output • PWM-type switching power supply control • Low-voltage operation (VCC = 3.6 to 22V) • Latch-mode short-circuit protection function (no malfunction by noise) • Soft-start function • Undervoltage lockout function • One capacitor shared for short circuit protection and for softstart to minimize the number of external discrete components ■ Applications • Battery power supply for portable equipment 1 FA7610CP(N)/FA7612CP(N)/FA7617CP(N) ■ Block diagram Á FA7610CP(N) Pin No. Pin symbol Description 1 IN (–) FB GND OUT VCC Inverting input to error amplifier Capacitor for soft-start, short-circuit protection and delay 8 CS CT REF Pin No. Pin symbol Description 1 IN (–) FB GND OUT Inverting input to error amplifier Power supply 8 VCC CS CT REF Pin No. Pin symbol Description 1 IN (–) FB Inverting input to error amplifier Ground 7 GND OUT VCC CS CT 8 REF Reference voltage output (2.5V) 2 3 4 5 6 7 Error amplifier output Ground Output Power supply Oscillator timing capacitor Reference voltage output (2.5V) Á FA7612CP(N) 2 3 4 5 6 7 Error amplifier output Ground Output Capacitor for soft-start, short-circuit protection and delay Oscillator timing capacitor Reference voltage output (2.5V) Á FA7617CP(N) 2 3 4 5 6 2 Error amplifier output Output Power supply Capacitor for soft-start, short-circuit protection and delay Oscillator timing capacitor FA7610CP(N)/FA7612CP(N)/FA7617CP(N) ■ Absolute maximum ratings (Ta = 25°C) Item Symbol Supply voltage Reference voltage output current Output current Total power dissipation Operating temperature Storage temperature Rating Unit FA7610C FA7612C/17C VCC IOR IO 22 22 V 5 5 mA ±50 80 mA Pd Topr Tstg 400 400 mW –20 to +85 –20 to +85 °C –40 to +150 –40 to +150 °C Symbol FA7610C ■ Recommended operating conditions Item FA7612/17C Min. Max. 3.6 20 Oscillator timing resistance VCC RNF CT RT Oscillation frequency fOSC Supply voltage Feedback resistance Oscillator timing capacitor 100 Unit Min. Max. 3.6 20 V 100 kΩ 220 22,000 220 22,000 pF 10 100 10 100 kΩ 5 200 5 500 kHz ■ Electrical characteristics (Ta = 25°C, VCC = 6V, RT = 33kΩ, CT = 1000pF) Reference voltage section Common to FA7610C/12C/17C Item Symbol Test condition Typ. Max. Unit Output voltage VREF LINE IOR = 1mA 2.528 VCC = 3.6 to 20V, IOR = 1mA 2.580 2.632 V 4 12 mV LOAD VTC1 VTC2 IOR = 0.1 to 1mA 1 6 mV Line regulation Load regulation Output voltage variation due to temperature change Min. Ta = –20 to +25°C –1 1 % Ta = +25 to +85°C –1 1 % Oscillator section Common to FA7610C/12C/17C Item Symbol Test condition Min. Typ. Max. Unit Oscillation frequency fOSC fdV fdT CT = 1000pF, RT = 33kΩ VCC = 3.6 to 20V 100 111 122 kHz Frequency variation 1 (due to supply voltage change) Frequency variation 2 (due to temperature change) Ta = –20 to +85°C 1 % 5 % Error amplifier section Common to FA7610C/12C/17C Item Symbol Reference voltage VB IB AV GB Input bias current Open-loop voltage gain Unity-gain bandwidth Test condition Output source current (Pin 2) Typ. Max. Unit 0.525 0.535 V 5 100 70 RNF = 100kΩ RNF = 100kΩ VOM = 1V nA dB 0.6 VOM+ VOM– IOM+ Maximam output voltage (Pin 2) Min. 0.515 MHz VREF–0.2 40 V 85 200 mV 200 µA PWM comparator section Item Symbol Test condition FA7610C Min. Max. 0.95 VTH0 VTH50 Duty cycle = 0% 0.85 Input threshold voltage (pin 2) Duty cycle = 50% 1.1 Maximum duty cycle αM (Pin 2 = 1.2V) Input threshold voltage (pin 2) 58 FA7612C Typ. 64 Min. FA7617C Typ. Max. 0.85 0.95 Min. 1.1 75 100 Unit Typ. Max. 0.85 0.95 1.1 63 67 V V 71 % 3 FA7610CP(N)/FA7612CP(N)/FA7617CP(N) Soft-start circuit section Common to FA7610C/12C/17C Item Symbol Input bias current (Pin 6) IBCS VTH CS0 VTH CS50 Input threshold voltage (Pin 6) Input threshold voltage (Pin 6) 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 Common to FA7610C/12C/17C Item Symbol Test condition Input threshold voltage (Pin 2) VTH PC ICHG VTH LA Pin 6 = 0V, Pin 2 = 2V Charge current (Pin 6) Latch-mode threshold voltage (Pin 6) Min. Typ. Max. Unit 1.20 1.50 1.80 V 20 30 40 µA 1.20 1.50 1.80 V Min. Typ. Max. Unit Undervoltage lockout circuit section Common to FA7610C/12C/17C Item Symbol OFF-to-ON threshold voltage VTH ON VTH OFF VHYS ON-to-OFF threshold voltage Voltage hysteresis Test condition 2.70 60 V 2.52 V 180 mV Output section Item Symbol Test condition FA7610C H-level output voltage (Pin 4) RL = 10kΩ L-level output voltage (Pin 4) VOH VOL Output source current (Pin 4) ISOURCE Pin 4 = 0V 8 Symbol Test condition FA7610C Min. Typ. 3.5 4.0 Output sink current = 20mA FA7612C/17C Max. Min. — 0.25 0.65 11 14 — Unit Typ. Max. — — V 0.9 1.5 V — — mA Overall device Item Min. FA7612C/17C Typ. Max. Min. Typ. Max. Unit Supply current ICC LA Latch mode 1.6 2.2 1.5 2.2 mA Operating-state supply current ICC AV RL = ∞ 2.6 3.8 1.8 3.0 mA Duty cycle = 50% 4 FA7610CP(N)/FA7612CP(N)/FA7617CP(N) ■ Characteristic curves (Ta = 25°C) Oscillation frequency(fOSC ) vs. timing capacitor capacitance(C T) Output duty cycle vs. CS terminal voltage(VCS ) Output source current (Isource) vs. supply voltage(VCC ) L-level output voltage(VOL ) vs. output sink current (ISINK ) Supply current(ICC) vs. supply voltage(VCC) Error amplifier frequency(f) vs. voltage gain(AV) / phase (θ) 5 FA7610CP(N)/FA7612CP(N)/FA7617CP(N) ■ Application circuit Á FA7610CP(N) Flyback-transformer type converter circuit Á FA7612CP(N) Chopper type buck converter circuit 6 FA7610CP(N)/FA7612CP(N)/FA7617CP(N) Á FA7617CP(N) Flyback-transformer type converter circuit 330k 2.5V 180k VCC 4.7µ 36k 0.01µ R2 VCC + 1000p R3 Q1 8 7 VREF OSC. 5 6 30µA + L.O S.C.P U.V.L.O + OFF + + 0.52V + + ER. AMP 1 TR PWM 2 +5V OFF 3 + 4 0.01µ –5V + 1k 2.2k 18.75k Parts tolerances characteristics are not defined in the circuit design sample shown above. When designing an actual circuit for a product, you must determine parts tolerances and characteristics for safe and economical operation. Please connect a capacitor, which the value is about 0.01 µF to 0.1µF, between VCC and REF terminals in order to prevent from irregular output pulse at start up. 7