Datasheet

If the voltage at the SNS pin is less than V
SNSLO
, the
MOD output is switched high to pass charge current to
the battery.
When the SNS voltage is greater than V
SNSHI
, the MOD
output is switched low—shutting off charging current to
the battery.
V
SNSLO
= 0.04 ∗ V
CC
± 25mV
V
SNSHI
= 0.05 ∗ V
CC
± 25mV
When used to gate an externally regulated current
source, the SNS pin is connected to V
SS
, and no sense
resisitor is required.
7
BD200401.eps
Timing
Control
OSC
Display
Control
Charge Control
State Machine
Discharge
Control
MOD
Control
TCO
Check
LTF
Check
A/D
EDV
Check
MCV
Check
DIS MOD INH V
CC
V
SS
BAT
SNS
TS
TCOTM2TM1
LED1
DCMD
DVEN
V
TS
- V
SNS
V
BAT
- V
SNS
LED2
DSEL
PWR
Control
Figure 3. Block Diagram
Mode 1 Charge Status LED
1
LED
2
DSEL = V
SS
Battery absent Low Low
Fast charge pending or discharge-before-charge in progress High High
Fast charge in progress Low High
Charge complete, top-off, and/or trickle High Low
Mode 2 Charge Status LED
1
LED
2
DSEL = Floating
Battery absent, fast charge in progress or complete Low Low
Fast charge pending High Low
Discharge in progress Low High
Top-off in progress High High
Mode 3 Charge Status LED
1
LED
2
DSEL = V
CC
Battery absent Low Low
Fast charge pending or discharge-before-charge in progress Low
1/8s high
1/8s low
Fast charge in progress Low High
Fast charge complete, top-off, and/or trickle High Low
Table 2. bq2004 LED Status Display Options
bq2004