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© 2021 ROHM Co., Ltd.
No. 64UG016E Rev.001
MAY.2021
User’s Guide
Battery Charger Series
Linear Charger for Low Voltage Battery
BD71631QWZ EVK
BD71631QWZ-EVK-001 (5V
→
4.2V, 0.1A)
Introduction
This user’s guide provides the necessary steps to operate the EVK of ROHM’s BD71631QWZ linear charger for low charge
voltage battery. This include the external parts, operating procedures, and application data.
Description
This EVK is for evaluating the linear charging IC BD71631QWZ, and charges 4.2V from the 5V input voltage. BD71631QWZ
accepts a power supply input range of 2.9V to 5.5V and generates a charging battery voltage ranging from 2.0V to 4.7V
using
external resistors.
If the charging current is VIN ≥ 4 V, it can be used up to 300 mA under the condition of VIN-VOUT ≥ 1 V and
up to 100 mA under the condition of VIN-VOUT ≥ 0.3 V. If 2.9 V ≤ VIN ≤ 5.5 V, it can be used up to 30 mA under the condition of
VIN-VOUT ≥ 0.3 V. The charging current can be set with an external resistor.
The termination current can be set from 50 μA to 10
mA using external resistors. Additional protection functions include a built-in Fixed 10-hour Safety Timer, UVLO (Under Voltage
Lock Out), TSD (Thermal Shutdown Detection), and Battery Over Voltage Protection.
Application
Low Voltage Battery Products
Li-ion 1Cell Battery Products
Operating Limits
Table 1. Operating Limits
Parameter
Symbol
Min
Typ
Max
Units
Conditions
Input Voltage
VIN
4.5
5.0
5.5
V
Charge Voltage
V
CHG
4.2
V
RVFB1
=180k
Ω
, RVFB2=30k
Ω
Pre Charge Voltage
V
PRE
0.7
V
Re Charge Voltage
V
RECHG
3.0
V
RVFBRE1=120k
Ω
, RVFBRE2=30k
Ω
Charge Current
I
CHG
98
mA
RICHG1=5.1k
Ω
Termination Current
I
TERM
0.98
mA
RITERM=51k
Ω
VOUT Leak Current
I
BAT
0
1
µA
VIN=Open
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