FOR AUTOMOTIVE BATTERY PROTECTION IC FOR 3-SERIAL TO 5-SERIAL CELL PACK (SECONDARY PROTECTION)

S-8235A Series

Seiko Instruments Inc.

16

7. Example of self-test operation

By connecting in cascade, the S-8235A Series performs a self-test operation in 6-serial or more cells protection circuit.

The example of a self-test operation at the time of cascade connection is as follows.

Refer to Table 6 in " Operation" for the output pin voltage to be set depending on the input pin voltage.

CLKI (1)

RSTI (1)

CLKO (1)

RSTO (1)

CAO (1)

CAI (1)

CO (1)

CTL (1)

CLKI (2)

RSTI (2)

CLKO (2)

RSTO (2)

CAO (2)

CAI (2)

CO (2)

CTL (2)

K

C

1

2

1

D

H

L

A

F

B

G

J

E

I

Figure 10 Timing Chart during Self-test Operation in 8-serial Cell (5-cell

+ 3-cell) Protection Circuit

<A> When inputting "L" to the RSTI pin of the S-8235A (1) (hereinafter, it is indicated as (1)), the self-test operation is

initiated.

<B> When a clock signal is input to the CLKI pin of (1), the overcharge detection operation of (1) is confirmed.

<C> It is possible to confirm that the self-test operation is performed in (1).

<D> The RSTO pin of (1) outputs "L", and then the voltage is input to the RSTI pin of the S-8235A (2) (hereinafter, it

is indicated as (2)).

<E> The CLKO pin output of (1) is input to the CLKI pin of (2).

<F> When a clock signal is input to the CLKI pin of (2), the overcharge detection operation of (2) is confirmed.

<G> The CO pin output of (2) is input to the CTL pin of (1).

<H> The CO pin output of (2) is output from the CO pin of (1).

<I> The CAO pin output of (2) is input to the CAI pin of (1).

<J> It is possible to confirm that the self-test operation is performed in (2).

<K> When inputting "H" to the RSTI pin of (1), the RSTO pin outputs "H".

<L> When "H" is input to the RSTI pin of (2), the self-test operation is terminated.

Caution 1. The S-8235A Series changes to the overcharge status if the voltage between voltage monitoring

operation is performed in battery voltage drop, the S-8235A Series may not detect the

overcharge.