Rev. 8/10/01

LP2950/51 100mA Low Dropout Voltage Regulators

©Copyright 2001 Sipex Corporation

10

LP2950/LP2951

TYPICAL APPLICATIONS (continued)

100k

Ω

SENSE

SD

GND

3

8

1

1

µF

+

4

400kΩ

120k

Ω

1.5k

Ω

6V

SEALED

LEAD-

ACID

BATTERY

SOURCE

FB

FOR 5.5 V

+

1N457

2

20k

Ω

NI-CAD

BACKUP

BATTERY

MEMORY V+

MAIN V+

SPX385

LP2951

GND

4

3

5

8

2

1

7

6

SD

TAP

FB

SENSE

ERROR

______

RESET

100k

100k

100k

1k

100k

10k

20k

1k

39k

39k

C3

C1

C2

C4

1%

1%

1%

1%

6V

LEAD-

ACID

BATTERY

<6.2V**

<5.8V**

<6.0V**

-

+

+

+

+

-

-

-

+V

1uF

+

* OPTIONAL LATCH OFF WHEN DROPOUT OCCURS. ADJUST R3 FOR C2 SWITCHING WHEN

LP2951

Figure 5. Low Battery disconnect

Figure 6. Regulator with State-of Charge Indicator