KA35S280/281

Lead-Acid Battery Charger

2011 Nov 18

© 2011

5

- Pin Configuration

- Mode selection pins

The KA35S28X can be programmed into 3 different charge algorithm named as 3-step

voltage, current and pulsed current by mode selection pins. Table 3 shows the relations

between MS0/MS1 selection pins and IC operation.

Table 3

– Mode Selection pins

MS1

MS0

Mode

Description

0

0

0

Charge is disabled

0

1

1

3-step voltage charge

1

0

2

Current charge

1

1

3

Pulsed current Charge

- Faster charge pin

The faster charge pin can be change internal DC voltage threshold of max current by 25%

(50mV). In normal condition it is configured to 200mV by internal voltage reference

generator unit.

Table 4

– Mode Selection pins

Faster Pin

Description

0

Charge current increased by 25%

1

Normal current charge

- Cyclic/Float use pin

Due to recent design breakthroughs, the same battery may be used in either cyclic or

standby applications and it is necessary to set the charge voltage according to it. Inaccurate

voltage settings cause over- or under-charge. In applications where standby power is

required to operate when the power has been interrupted, continuous float charging is

recommended. Non-continuous cyclic charging is used primarily with portable equipment

where charging on an intermittent basis is appropriate.

The cyclic/float pin can be change internal charge reference voltage and method of

temperature compensation.

Table 5

– Mode Selection pins

Cyclic/Float Pin

Description

0

In cyclic use

1

In float use

- Fixed and Configurable Thresholds

The KA35S28X uses the following fixed thresholds:

Conditioning Current: Used in the maintenance phase of the Current algorithm

Also the KA35S28X uses the following configurable thresholds:

Upper voltage limit during fast charge, typically specified by the battery

manufacturers to be 2.3V in float and 2.45 in cyclic applications per cell @

Minimum charge voltage required to compensate

for the battery’s self-discharge

rate and maintain full charge on the battery.