LP2950/LP2951
TYPICAL APPLICATIONS (continued)
+
6V
SEALED
1.5kΩ
120kΩ
LEAD-
8
ACID
1N457
BATTERY
SOURCE
+VIN
FB
SPX385
1
2
MAIN V+
OUT
V
LP2951
MEMORY V+
SENSE
400kΩ
+
FOR 5.5 V
3
20kΩ
1µF
SD
100kΩ
GND
4
NI-CAD
BACKUP
BATTERY
Figure 5. Low Battery disconnect
8
2
Ω
39k ..
SENSE
+V
_____IN_
ERROR
+VOUT = 5V
5
1
7
VOUT
RESET
+
1uF
LP2951
-
3
C4
+
SD
FB
TAP
Ω
39k ..
GND
4
6
Ω
100k
1%
..
Ω
100k
-
..
C1
C2
+
6V
LEAD-
ACID
Ω
..
1k
<5.8V**
<6.0V**
<6.2V**
1%
1%
Ω
-
100k
..
BATTERY
+
Ω
-
100k ..
Ω
1k
..
C3
+
Ω
10k
..
R3
* OPTIONAL LATCH OFF WHEN DROPOUT OCCURS. ADJUST R3 FOR C2 SWITCHING WHEN
VIN IS 6.0V
* OUTPUTS GO LOW WHEN V IN DROPS BELOW DESGNATED THRESHHOLDS
Ω
1%
20k ..
Figure 6. Regulator with State-of Charge Indicator
Rev. 8/10/01
LP2950/51 100mA Low Dropout Voltage Regulators
©Copyright 2001 Sipex Corporation
10