SM6781BV Datasheet, PDF (2/10 Pages) Nippon Precision Circuits Inc – Ni-MH/Ni-Cd Battery Charger IC

BLOCK DIAGRAM
SM6781BV
DC
Input
Current
Source
Battery
Pack
BATT
INH
VDD
Reference
Regulators
Max/Min
Cell-voltage
Check
OSC
VDD
TIME
Timer Mode
Selector
−∆V
A/D Function
Block
Timing Control
Logic
Charge Control
Logic
CHG Driver
LED Driver
VSS
CHGN
VDD
LEDN
NC
PIN DESCRIPTION
Number
1
Name
TIME
2
LEDN
3
BATT
4
VSS
5
VDD
6
NC
7
INH
8
CHGN
I/O
Description
Timer mode select input (3-level)
I
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.
Charge status display LED driver output (open-drain output)
O
LOW-level output in quick charge mode. 1Hz pulse output when abnormal battery voltage is detected
during quick charge. High impedance when charging finishes.
I
Battery voltage detector input.
Connect a high-impedance resistor voltage divider between the poles of the battery for voltage detection.
–
Ground
–
Supply
–
No connection (must be open)
Inhibit input
I
Charging operation is stopped when HIGH. Charging recommences with the same charging parameters
when INH goes LOW again.
O
Charge control (open-drain output)
High impedance output when charging current is flowing. LOW-level output when charging current stops.
NIPPON PRECISION CIRCUITS—2