SM6781BV

NIPPON PRECISION CIRCUITS—2

BLOCK DIAGRAM

PIN DESCRIPTION

Number

Name

I/O

Description

1

TIME

I

Timer mode select input (3-level)

HIGH and LOW levels applied using pull-up and pull-down, respectively. MID-level is applied using a

voltage divider resistor network with voltage VDD/2.

2

LEDN

O

Charge status display LED driver output (open-drain output)

LOW-level output in quick charge mode. 1Hz pulse output when abnormal battery voltage is detected

during quick charge. High impedance when charging finishes.

3BATT

I

Battery voltage detector input.

Connect a high-impedance resistor voltage divider between the poles of the battery for voltage detection.

4

VSS

–

Ground

5

VDD

–

Supply

6

NC

–

No connection (must be open)

7INH

I

Inhibit input

Charging operation is stopped when HIGH. Charging recommences with the same charging parameters

when INH goes LOW again.

8

CHGN

O

Charge control (open-drain output)

High impedance output when charging current is flowing. LOW-level output when charging current stops.

Reference

Regulators

INH

Max/Min

Cell-voltage

Check

OSC

BATT

A/D

−∆V

Function

Block

Timer Mode

Selector

Timing Control

Logic

Charge Control

Logic

CHG Driver

LED Driver

CHGN

VSS

LEDN

NC

VDD

VDD

TIME

VDD

DC

Input

Current

Source

Battery

Pack