S-1170B Seiko Instruments, S-1170B Datasheet - Page 15

• Manufacturer Part Number: S-1170B
• Description: Voltage Regulator
• Manufacturer: Seiko Instruments

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HIGH RIPPLE-REJECTION LOW DROPOUT HIGH OUTPUT CURRENT CMOS VOLTAGE REGULATOR
Rev.3.0
4. T hermal shutdown circuit
The S-1170 Series implements a thermal shutdown circuit to protect the device from damage due to
overheating. When the junction temperature rises to 150°C (typ.), the thermal shutdown circuit operates
and the regulator operation stops. When the junction temperature drops to 120°C (typ.), the thermal
shutdown circuit is released and the regulator operation resumes.
If the thermal shutdown circuit starts operating due to self-heating, the regulator operation stops and the
output voltage falls.
temperature of the IC is lowered. When the temperature has dropped, the thermal shutdown circuit is
released, the regulator operation resumes, and self-heat is generated again. By repeating this procedure,
the output voltage waveform forms pulses. This phenomenon, stopping and resuming the regulator
operation, continues until the internal power consumption is reduced by reducing either the input voltage
or output current or both, or the ambient temperature is lowered.
Thermal Shutdown Circuit
Operating: 150°C (typ.)
_00
Released: 120°C (typ.)
When the regulator operation has stopped, no self-heat is generated and the
Table 7
Seiko Instruments Inc.
VOUT Pin Voltage
Set value
V
SS
level
S-1170 Series
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