FAN1950 Datasheet, PDF (8/11 Pages) Fairchild Semiconductor – 1.5A Low-Voltage Low-Dropout Regulator

FAN1950/FAN1951
Input and Output Capacitor Requirements
A 4.7µF or greater Input Capacitor (Ceramic or Tanta-
lum), installed closely between VIN and GND leads of
the part, is required for stability, better transient
response, noise and ripple rejection. A higher value of
electrolytic input capacitor can be recommended if the
bulk capacitor of the power supply is located more than
3– 4 inches from the device or a large and fast-rise-
time load is a requirement.
FAN1950 and FAN1951, as most of LDO regulators,
require an Output Capacitor. The recommended value
of this capacitor is 10µF. The larger capacitor will
additionally improve the Transient Response, Ripple
Rejection and output noise. The low-ESR Tantalum
capacitors are the best for this application: they provide
stable work and good transient response over the tem-
perature range. Using the Ceramic capacitors as the
Output capacitor can provoke instability (oscillation in
the Output Voltage).
Aluminum electrolytic capacitors also can be used if
their ESR is below 3Ω.
8
REV. 0.1.6 8/30/04