R1190 Datasheet, PDF (8/27 Pages) RICOH electronics devices division – 1A VOLTAGE REGULATOR (Operating Voltage up to 16V)

R1190x
Inrush-Current Limit Function
R1190x Series has the function to limit the inrush-current, it limited approximately 0.3A when the voltage
regulator is turn ON. It is also possible to set time of the rush-current limitation by connecting capacitor with
DELAY pin. The rush-current time (tD) and the value of capacitor (CD(F)) is calculatable by the following formula;
tD=(0.000198+(3.79×10⁷×CD))×VIN
The inrush-current is limited even if the capacitor is not connected with the DELAY pin. In this case, the time is
calculated as CD=0 by the formula above.
Though, if the value of time is insufficient for controlling the inrush-current, please connect the capacitor with
DELAY pin. The DELAY pin is used as OPEN when the capacitor is not used. Please use the DELAY pin as
OPEN when the capacitor is not used.
Auto-Discharge Function
R1190xxxxD series has the auto-discharge function. When "L" signal is put into the Chip-enable pin (CE), the
switch between VOUT and GND is turned ON and the charge at capacitor is discharge rapidly by the auto-discharge
function.
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