EUP9261
Application Circuit
Figure2.
Symbol
Parts
N channel
MOSFET
Purpose
Recommend
min.
max.
Remarks
Threshold voltage
≤
Overdischarge
detection voltage *1
Gate to source withstand voltage
≥
Charge voltage*2
Threshold voltage
≤
Overdischarge
detection voltage *1
Gate to source withstand voltage
≥
Charge voltage*2
Resistance should be as small as
possible to avoid lowering of the
overcharge detection accuracy caused
by VDD pin current. *3
Install a capacitor of 0.022µF or higher
between VDD and VSS. *4
Select a resistance as large as possible
to prevent current when a charger is
reversely connected. *5
FET1
Charge control
--
--
--
FET2
N channel
MOSFET
Discharge control
--
--
--
R1
Resistor
ESD protection
For power fluctuation
For power fluctuation
Protection for
reverse connection
of a charger
470Ω
300Ω
1kΩ
C1
R2
Capacitor
Resistor
0.1µF
2kΩ
0.022µF
300Ω
1.0µF
4kΩ
*1
If the threshold voltage of an EFT is low, the FET may not cut the charging current.
If an FET with a threshold voltage equal to or higher than the overdischarge detection voltage is used, discharging may be stoped
before overdischarge is detected.
*2
If the withstand voltage between the gate and source is lower than the charger voltage, the FET may destroy.
*3
If R1 has a high resistance, the voltage between VDD and VSS may exceed the absolute maximum rating when a charger is
connected reversely since the current flows from the charger to the IC.
Insert a resistor of 300Ω or higher as R1 for ESD protection.
*4
If a capacitor of less than 0.022µF is installed as C1,DO may oscillate when load short-circuiting is detected.
Be sure to install a capacitor of 0.022µF or higher as C1.
*5
If R2 has a resistance higher than 4kΩ, the charging current may not be cut when a high-voltage charger is connected.
Remark
Caution
The DP pin should be open.
The above connection diagram and constant will not guarantee successful operation. Perform through evaluation
using the actual application to set the constant.
DS9261 Ver2.4 Jan. 2007
6
EUTECH [ EUTECH MICROELECTRONICS INC ]
