HA16138PS Datasheet, PDF (9/20 Pages) Hitachi Semiconductor – AC/DC Switching Converter Controller IC With High-Voltage Power MOS FET

HA16138PS
Remote On/Off Circuit
When the CT pin voltage is pulled up to 3.8 V or above, the remote on/off circuit operates and PWM
output can be stopped without turning off the power supply. When stoppage is executed by means of the
on/off circuit, PWM output and the starter circuit are stopped, and the soft start circuit is reset, but the
reference voltage generation circuit does not stop.
DRAIN
0
CT
3.8V
Vref
(IC internal 5V
waveform)
Figure 5 Remote On/Off Operation Timing
Soft Start Circuit
This circuit implements a soft start function with a 2 ms time constant without the use of external parts.
During a soft start, the PWM output pulse width gradually increases. The soft start time is defined as the
time from the point at which the UVL circuit start voltage is exceeded to the point at which PWM output
reaches its maximum duty.
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