FA3686

FA3686V s Description FA3686V is a PWM type DC-to-DC converter control IC with 2ch outputs that can directly drive power MOSFETs. CMOS devices with high breakdown voltage are used in this IC and low power consumption is achieved. This IC is suitable for very small DC-to-DC converters because of their small and thin package (1.1mm max.), and high frequency operation (to 1.5MHz). This IC contains built-in an error amplifier for series regulators, therefore, this IC is suitable for the 3ch power supply with a 2ch DC-to-DC converter and a 1ch series regulator. CMOS IC For Switching Power Supply Control FA3686V s Dimensions, mm TSSOP-16 16 9 • Wide range of supply voltage: VCC=2.5 to 20V • MOSFET direct driving • Low operating current consumption by CMOS process: 3.0mA (typ.) • 2ch PWM control IC • High frequency operation: 300kHz to 1.5MHz • Simple setting of operation frequency by timing resistor • Built-in error amplifier for series regulator • Soft start function on each channel (1ch, 2ch only) • Maximum output duty cycle: 85% (typ.), at 500kHz • Built-in under voltage lockout • High accuracy reference voltage: VREF: 1.00V±1%, VREG: 2.20V±1% • Timer latch for short-circuit protection with counter • PGS pin for a power supply fault signal • Thin and small package: TSSOP-16 5 0.10±0.05 1 0.105 to 0.145 s Features 8 4.4 6.4±0.2 0~8˚ 0.5±0.08 0.22±0.02 0.65 s Block diagram Pin No. Pin symbol Description 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 FB3 IN3FB2 IN2PGS VCC CS2 OUT2 OUT1 CS1 GND RT VREG IN1FB1 TL Ch.3 output of error amplifier Ch.3 inverting input to error amplifier Ch.2 output of error amplifier Ch.2 inverting input to error amplifier PGS signal output Power supply Soft start for Ch.2 Ch.2 output Ch.1 output Soft start for Ch.1 Ground Oscillator timing resistor Regulated voltage output Ch.1 inverting input to error amplifier Ch.1 output of error amplifier Timer latched short circuit protection 1.1max 1 FA3686V s Absolute maximum ratings Item Power supply voltage PGS pin voltage FB1, IN1–, FB2, IN2–, FB3, IN3– pin voltage CS1, CS2, RT, TL, VREG pin voltage OUT1/2 OUT pin source current OUT pin sink current OUT1/2 OUT pin source current OUT pin sink current Power dissipation * Operating junction temperature Operating ambient temperature Storage temperature * Derating factor Ta 25˚C: 3mW/˚C Symbol VCC VPGS VEA_IN VCTR_IN IOUT– IOUT+ IOUT– IOUT+ Pd TJ TOPR TSTG Rating 20 20 –0.3 to 5.0 –0.3 to 5.0 –400 (peak) 150 (peak) –50 (continuous) 50 (continuous) 300 (Ta 25˚C) +125 –30 to +85 –40 to +125 Unit V V V V mA mA mA mA mW ˚C ˚C ˚C Maximum power dissipation curve Maximun power dissipation [mW] 350 300 250 200 150 100 50 0 -30 0 30 60 90 120 150 Ambient temperature [˚C] s Recommended operating conditions Item Supply voltage CS1, CS2, TL pin voltage IN1–, IN2–, IN3– pin voltage Oscillation frequency VREG pin capacitance VREG pin current VCC pin capacitance CS1 pin capacitance CS2 pin capacitance Symbol VCC VCTR_IN VEA_IN fOSC CREG IREG CVCC CCS1 CCS2 Between CS1 and GND Between CS2 and VREG 1.0 0.01 0.01 Vcc