LP2950 Datasheet, PDF (10/16 Pages) National Semiconductor (TI) – Series of Adjustable Micropower Voltage Regulators

LP2950
TYPICAL APPLICATIONS
Figure 18. Lithium Ion Battery Cell Charger
Unregulated Input
6.0 to 10 Vdc
8
NC
5
Error
Vin
Vout
1
SNS ² NC
0.1 µF ₃
LP2951CN
SD VO T
6
NC
Gnd FB
4
7
1N4001 4.2 V ± 0.025 V
330 pF
2.0 M
1.0%
2.2 µF
806 k
1.0%
50 k
Lithium Ion
Rechargeable
Cell
Gnd
Figure 19. Low Drift Current Sink
+V = 2.0 to 30 V
IL
Load
IL = 1.23/R
Error
Output
Shutdown
Input
8
5
Error
Vin
Vout
1
SNS ²
LP2951CN
3 _SD
VO T ⁶
Gnd FB
4
7
R
0.1 µF
1.0 µF
Figure 20. Latch Off When Error Flag Occurs
Figure 21. 5.0 V Regulator with 2.5 V Sleep Function
+Vin
470 k
8
2N3906
5
Error
Vin
Vout
1
470 k
SNS ² NC
Reset
LP2951CN
3 _SD
VO T ^{6 NC}
R1
Normally
Closed
Gnd FB
4
7
R2
Error flag occurs when Vin is too low to
maintain Vout, or if Vout is reduced by
excessive load current.
+Vin
CMOS
*Sleep
Gate
Input
47 k
Vout
Error
Output
Shutdown
Input
1.0 µF
8
470 k
5
Error
Vin
Vout
1
2N3906
Vout
SNS ² NC
LP2951CN
3 _SD
VO T ^{6 NC}
Gnd FB
4
7
200 k
3.3 µF
100 k ^{100 pF}
100 k
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