HA17524P

HA17524P/FP Switching Regulator Controller Features Pulse width modulation (PWM) Wide oscillation frequency range: 450 kHz(typ) Low quiescent current: 5 mA typ Good line regulation (0.2% typ) and load regulation (0.4% typ) Independent output stages for 2 channels Wide external circuit applications including single-end and push-pull method Reference power source output stage and switching output stage include current limiting protection circuit. Ordering Information Type No. HA17524P HA17524FP Package 16 pin dual in line plastic(DP-16) 16 pin flat plastic (FP-16DA) Pin Arrangement INV. Input NON-INV. Input OSC Out CL(+) CL(–) RT CT GND 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 (Top View) V REF VCC E2 C2 C1 E1 SHUT DOWN COMP HA17524P/FP Functional Description Principals of HA17524 Operation The HA17524 switching regulator circuit, using pulse width modulation (PWM), is constructed as shown in figure 1. Timing resistances RT and timing capacitance C T control the oscillation frequency. CT is charged by a constant current generated by RT . Ramp signals (saw-tooth waves) at the CT terminal generated by this oscillator is available for reference input signal to comparator which control the pulse width. VREF VCC 15 Ref. Volt. +5 V RT 6 CT 7 (Ramp) Osc. 16 +5 V to internal circuitry +5V OSC Out Q 3 Flip Flop Q +5V — 12 C1 NOR Q1 11 E 1 13 C2 NOR Q2 14 E 2 4 CL(+) 5 CL(—) Comparator INV. Input 1 NON-INV. Input 2 GND 8 +5V — Error Amp. + + +5V + C.L. — 10 SHUT DO...