11

ICS1712

Charge Rate Selection: SEL0, SEL1 Pins

The SEL0 and SEL1 inputs must be programmed by the user to

inform the ICS1702 of the desired charge rate. When a low level is

required, the pin must be grounded. When a high level is required,

no connection is required since each pin has an internal 75k

up to V

DD

. The voltage ranges for low (L) and high (H) are listed in

Table 8, DC Characteristics. To program the SEL0 and SEL1

inputs, refer to the Charge Rate List in Table 3.

The ICS1712 does not control the current flowing into the battery

in any way other than turning it on and off. The required current

for the selected charge rate must be provided by the user’s power

source. The external charging circuitry should provide current at

the selected charge rate. For example, to charge a 1.2 ampere hour

battery in 30 minutes (2C), approximately 2.4 amperes of current is

required.

Table 3: Charge Rate List

SEL0

SEL1

Charge Rate

Topping Charge

pulse Rate

Maintenance Charge Pulse

Rate

Fast Charge Timer

Duration (after reset)

L

L

4C (15 min)

one every 40 sec

one every 160 sec

30 min

L

H

2C (30 min)

one every 20 sec

one every 80 sec

60 min

H

L

1C (60 min)

one every 10 sec

one every 40 sec

90 min

H

H

C/2 (120 min)

one every 5 sec

one every 20 sec

210 min

See the section on Controller Operation for additional information on the topping charge and maintenance charge. See the section on Charge Termination

Methods for additional information on the charge timer.