ha16138 HITACHI, ha16138 Datasheet - Page 9

• Manufacturer Part Number: ha16138
• Description: Ac/dc Switching Converter Controller With High-voltage Power
• Manufacturer: HITACHI

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.
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.
DRAIN
CT
Vref
(IC internal
waveform)
Figure 5 Remote On/Off Operation Timing
5V
0
3.8V
HA16138PS
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