HA16114P Datasheet, PDF (1/38 Pages) Hitachi Semiconductor – Switching Regulator for Chopper Type DC/DC Converter

HA16114P/PJ/FP/FPJ, HA16120FP/FPJ
Switching Regulator for Chopper Type DC/DC Converter
Description
The HA16114P/FP/FPJ and HA16120FP/FPJ are single-channel PWM switching regulator controller ICs
suitable for chopper-type DC/DC converters. Integrated totem-pole output circuits enable these ICs to
drive the gate of a power MOSFET directly. The output logic of the HA16120 is designed to control a
DC/DC step-up (boost) converter using an N-channel power MOS FET. The output logic of the HA16114
is designed to control a DC/DC step-down (buck) converter or inverting converter using a P-channel power
MOS FET.
These ICs can operate synchronously with external pulse, a feature that makes them ideal for power
supplies that use a primary-control AC/DC converter to convert commercial AC power to DC, then use one
or more DC/DC converters on the secondary side to obtain multiple DC outputs. Synchronization is with
the falling edge of the ‘sync’ pulse, which can be the secondary output pulse from a flyback transformer.
Synchronization eliminates the beat interference that can arise from different operating frequencies of the
AC/DC and DC/DC converters, and reduces harmonic noise. Synchronization with an AC/DC converter
using a forward transformer is also possible, by inverting the ‘sync’ pulse.
Overcurrent protection features include a pulse-by-pulse current limiter that can reduce the width of
individual PWM pulses, and an intermittent operating mode controlled by an on-off timer. Unlike the
conventional latched shutdown function, the intermittent operating function turns the IC on and off at
controlled intervals when pulse-by-pulse current limiting continues for a programmable time. This results
in sharp vertical settling characteristics. Output recovers automatically when the overcurrent condition
subsides.
Using these ICs, a compact, highly efficient DC/DC converter can be designed easily, with a reduced
number of external components.
Functions
• 2.5 V voltage reference
• Sawtooth oscillator (Triangle wave)
• Overcurrent detection
• External synchronous input
• Totem-pole output
• Undervoltage lockout (UVL)