S1142A Datasheet, PDF (15/32 Pages) Seiko Instruments Inc – HIGH-WITHSTAND VOLTAGE LOW CURRENT CONSUMPTION

HIGH-WITHSTAND VOLTAGE LOW CURRENT CONSUMPTION LOW DROPOUT CMOS VOLTAGE REGULATOR
Rev.4.2_00
S-1142A/B Series
5. Thermal shutdown circuit
The S-1142A/B Series has a thermal shutdown circuit to protect the device from damage due to overheat. When
the junction temperature rises to 150°C typ., the thermal shutdown circuit operates to stop regulating. When the
junction temperature drops to 125°C typ., the thermal shutdown circuit is released to restart regulating.
Due to self-heating of the S-1142A/B Series, if the thermal shutdown circuit starts operating, it stops regulating so
that the output voltage drops. When regulation stops, the S-1142A/B Series does not itself generate heat and the
IC’s temperature drops. When the temperature drops, the thermal shutdown circuit is released to restart regulating,
thus this IC generates heat again. Repeating this procedure makes the waveform of the output voltage into a
pulse-like form. Stop or restart of regulation continues unless decreasing either or both of the input voltage and the
output current in order to reduce the internal power consumption, or decreasing the ambient temperature.
Table 9
Thermal Shutdown Circuit
Operate: 150°C typ.^*1
Release: 125°C typ.^*1
VOUT Pin Voltage
V_SS level
Set value
*1. Junction temperature
Seiko Instruments Inc.
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