9

LTC1540

Low-Battery Detect

Figure 9 shows how to use the LTC1540 for a low-battery

detect, drawing only 1.4

low as 1.6V when the batteries are completely depleted.

The electrical specifications of the LTC1540 guarantee

operation down to a supply voltage of 2V, but it is still

functional with the supply as low as 1.6V. Some param-

supply voltages. The input voltage range extends from

0.9V below the positive supply to the negative supply.

Figure 9. Low-Battery Detect Works Down to 1.6V

R1

3M

R2

1.1M

21

7

8

OUT

GND

LBO

2-CELL

NiCd

LTC1540

1540 F09

REF

HYST

3

4

6

5

–

+

R3

40k

R4

1.2M

R5

1M