R1190 Datasheet, PDF (7/27 Pages) RICOH electronics devices division – 1A VOLTAGE REGULATOR (Operating Voltage up to 16V)

TYPICAL APPLICATION
VDD
VOUT
R1190x
C1
Series
CE
GND
DELAY
CD
R1190x
VOUT
C2
DELAY pin is OPEN when CD pin is not used.
(External Components)
C1, C2: Ceramic Capacitor 4.7µF Nippon Chemi-con Corporation KTD500B475M43A0T00
TECHNICAL NOTES
When using these ICs, consider the following points:
Phase Compensation
In these ICs, phase compensation is made for securing stable operation even if the load current is varied. For
this purpose, use a capacitor COUT with good frequency characteristics and ESR (Equivalent Series Resistance).
(Note: If additional ceramic capacitors are connected with parallel to the output pin with an output capacitor for
phase compensation, the operation might be unstable. Because of this, test these ICs with as same external
components as ones to be used on the PCB.)
PCB Layout
Make VDD and GND lines sufficient. If their impedance is high, noise pickup or unstable operation may result.
Connect a capacitor with a capacitance value as much as 4.7µF or more between VDD and GND pin, and as close
as possible to the pins.
Set external components, especially the output capacitor, as close as possible to the ICs, and make wiring as
short as possible. (Refer to the TYPICAL APPLICATION diagram above.)
Thermal Shutdown
There is the built-in thermal-shutdown function in R1190x series. It discontinues operation of the IC when the
junction temperature becomes over 150°C (Typ.) and IC re-operates when the junction temperature under 130°C.
If the temperature increasing keeps the IC repeats ON and OFF operating. The output becomes the pulse
condition.
Chip Enable Circuit
For the output voltage stability, please do not use the intermediate electric potential (the voltage value between
VCEH and VCEL) that causes the supply current increasing and the unstable of output voltage.
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