R1150H Datasheet, PDF (24/28 Pages) RICOH electronics devices division – VOLTAGE REGULATOR(with Wide Input Voltage Range) with RESET

R1150H
TECHNICAL NOTES
Phase Compensation
Phase Compensation of the R1150H Series has been made internally for stable operation even though the
load current would vary. Therefore, without the capacitors, CIN and COUT, Output Voltage is regulated, but for
more stable operation, use 0.1µF or more capacitors as CIN and COUT. Wiring should be made as short as
possible.
PCB layout
Current flows into wiring for VDD or GND, thus, if the impedance of the wiring is rather high, it may cause of
making noise or unstable operation, thus width and pattern should be enough wide to avoid such problems.
Connect the capacitor, CIN between VDD pin and GND pin as close as possible.
VIN CIN
5 VDD
VDET 4
R1150HxxxA
SERIES
3 _{CE GND} VOUT 1
2
470kΩ
IOUT
COUT
R1150HxxxA Typical Application
Thermal Shutdown
Thermal shutdown function is included in the R1150HxxxA/B/C/D Series, when the junction temperature is
equal or more than +150°C (Typ.), the operation of regulator would stop. After that, when the junction
temperature is equal or less than +120°C (Typ.), the operation of regulator would restart. Unless the cause of
rising temperature would remove, the regulator repeats on and off, and output waveform would be like
consecutive pulses.
Chip Enable Circuit
Do not make voltage level of chip enable pin keep floating level, or in between VIH and VIL. Unless otherwise,
Output voltage would be unstable or indefinite, or unexpected current would flow internally.
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