Rev. 3/6/03

SP2954 250mA Low Dropout Voltage Regulator

© Copyright 2003 Sipex Corporation

10

APPLICATIONS HINTS

100kΩ

SENSE

SD

GND

3

8

1

1µF

+

4

400kΩ

120kΩ

1.5kΩ

6V

SEALED

LEAD-

ACID

BATTERY

SOURCE

FB

FOR 5.5 V

+

1N457

2

20kΩ

NI-CAD

BACKUP

BATTERY

MEMORY V+

MAIN V+

SPX385

SPX2954

Figure 4. Low Battery Disconnect

Figure 5. Regulator with State of Charge Indicator

GND

4

3

5

8

2

1

7

6

S D

TAP

FB

SENS E

ERROR

______

RESET

100kΩ

1kΩ

100kΩ

10kΩ

20kΩ

1kΩ

39kΩ

39kΩ

C3

C1

C2

C4

1%

1%

1%

1%

6V

LEAD-

ACID

BATTERY

<6.2V**

<5.8V**

<6.0V**

-

+

+

+

+

-

-

-

+V

1uF

+

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

V

* OUTPUTS GO LOW WHEN V

SPX2954

100k

Ω

100kΩ