SI9731 Datasheet, PDF (7/10 Pages) Vishay Siliconix – UP Controlled Battery Charger For 1-Cell Li-ion or 1-Cell to 3-Cell NiCd/NiMH Batteries

BLOCK DIAGRAM AND TYPICAL APPLICATION CIRCUIT
Si9731
Vishay Siliconix
1
CHARGERPRESENTIN
16
CHARGERPRESENT
Q3
2
CHARGERPOWER_ONIN
15
CHARGERPOWER_ON
Q4
ON/OFF
4
100 kΩ
3
V_CHARGER
C_IN
2.2 μfd
5
TRICKLECHARGEEN
Latch
1 MΩ
UVL
+
2.6 V _–
OVP
–
12.8 V ₊
Battery Min Voltage
–
3.4 V
+
Circuit
Power
+
5V
–
OK to Charge
(OTC)
Battery Over
Voltage
+
–
Q2
Trickle
Charge
Q1
Fast
Charge ^RFB1
RFB2
14 ^VBAT+
V_BAT
C_OUT
2.2 μfd
B
a
t
t
e
56 Ω
r
y
13
Trickle_V_BAT
12 _{4.1 V_TAP}
6
CVMODE
MAINCHARGEEN
7
Document Number: 71321
S-60869-Rev. B, 22-May-06
Digital
+
RFB3
Q5
Enable
11
GND
Voltage
Generator
2.6 V
3.4 V
5V
12.8 V
Temp _Analog
OK
E/A
Temp
Sensor
–
+
Ref
Voltage
1.3 V
8
N/C
10
N/C
Figure 1.
9
V_REF
0.1 μfd
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7