SPX1129U-5.0(2004) Просмотр технического описания (PDF) - Signal Processing Technologies
Номер в каталоге
Компоненты Описание
производитель
SPX1129U-5.0 Datasheet PDF : 8 Pages
| |||
External Capacitors
The stability of the SPX1129 requires a 2.2µF or
greater capacitor between output and ground.
Oscillation could occur without this capacitor.
Most types of tantalum or aluminum electrolytic
works fine here. For operations of below -25°C
solid tantalum is recommended since the many
aluminum types have electrolytes that freeze at
about -30°C. The ESR of about 5Ω or less and
resonant frequency above 500kHz are the most
important parameters in the value of the capaci-
tor. The capacitor value can be increased with-
out limit.
The SPX1129, unlike other low dropout regula-
tors will remain stable and in regulation with no
load in addition to the internal voltage divider.
APPLICATION INFORMATION
This feature is especially important in applica-
tions like CMOS RAM keep-alive.
If there is more than 10 inches of wire between
the input and the AC filter capacitor, or if a
battery is used as the input, then a 0.1µF tanta-
lum or aluminum electrolytic capacitor should
be placed from the input to the ground.
Reducing Output Noise
It may be an advantage to reduce the AC noise
present at the output. One way is to reduce the
regulator bandwidth by increasing the size of
the output capacitor. Increasing the capacitor
from 1µF to 220µF decreases the noise from
430µV to 160µV rms for a 100kHz bandwidth
at 5V output.
Date: 5/25/04
SPX1129 400mA Low Dropout Voltage Regulator
3
©Copyright 2004 Sipex Corporation
Share Link: 