ISL6414 Datasheet, PDF (11/12 Pages) Intersil Corporation – Triple Output, Low-Noise LDO Regulator with Integrated Reset Circuit

ISL6414
50mΩ or less to insure stability and optimum transient
response. For stable operation, a ceramic capacitor whose
value is minimum 3.3µF is recommended for V_OUT1 for
300mA output current and 2.2µF is recommended for V_OUT2
and V_OUT3 each at 200mA load current. There is no upper
limit to the output capacitor value. Larger capacitor can
reduce noise and improve load transient response, stability
and PSRR. The output capacitor should be located very close
to V_OUT pins to minimize impact of PC board inductances and
should be returned to a clean analog ground.
Input-Output (Dropout) Voltage
A regulator’s minimum input-output voltage differential (or
dropout voltage) determines the lowest usable supply voltage.
In battery-powered systems, this determines the useful end-
of-life battery voltage. Because the ISL6414 uses a P-channel
MOSFET pass transistor, its dropout voltage is a function of
r_DS(ON) (typically 0.5) multiplied by the load current.
Noise, PSSR and Transient Response
The ISL6414 is designed to operate with low dropout
voltages and low quiescent current while still maintaining
good noise, transient response, and AC rejection. When
operating from noisy sources, improved supply-noise
rejection and transient response can be achieved by
increasing the values of the input and output bypass
capacitors and through passive filtering techniques.
The ISL6414 load transient response graph is presented in
application note AN1080. Increasing the output capacitor
value and decreasing the ESR attenuates the overshoot.
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