ICS1722
V
CONSTANT
CURRENT
SOURCE
in
R4 (note 1)
+ 5 V (note 5)
4.7µF
+ 5 V + 5 V
Q1 (note 2)
ICS1722
390 390
(note 3)
.047µF
1k
1
2
CHG
DCHG
PFN
VDD 16
R1
unused
VIN
15
14
FAULT 3
MAINT 4
MMN
CMN
SEL0
VSS
OPREF 13
AUX1 12
.047µF
R2
open
@ 45°C
CHG 5
+ 5 V
AUX0
RC
6
7
8
11
10
9
+ 5 V
R3
SEL1
MRN
16k
(note 6)
100pF
Notes:
1) Value of R4 determined by discharge current and capacity of battery pack.
2) Discharge FET is logic-level compatible in this application.
3) DC return of discharge FET must be connected close to negative battery terminal.
4) Regulated supply
5) Power ground; others are signal ground. Connect signal ground to power ground
at negative battery terminal only.
Figure 9: Functional Diagram
17