BQ2004 Datasheet, PDF (7/15 Pages) Texas Instruments – Fast-Charge IC

bq2004
If the voltage at the SNS pin is less than VSNSLO, the
MOD output is switched high to pass charge current to
the battery.
When the SNS voltage is greater than VSNSHI, the MOD
output is switched low—shutting off charging current to
the battery.
VSNSLO = 0.04 ∗ VCC ± 25mV
VSNSHI = 0.05 ∗ VCC ± 25mV
When used to gate an externally regulated current
source, the SNS pin is connected to VSS, and no sense
resisitor is required.
Mode 1
DSEL = VSS
Mode 2
DSEL = Floating
Mode 3
DSEL = VCC
Table 2. bq2004 LED Status Display Options
Charge Status
Battery absent
Fast charge pending or discharge-before-charge in progress
Fast charge in progress
Charge complete, top-off, and/or trickle
Charge Status
Battery absent, fast charge in progress or complete
Fast charge pending
Discharge in progress
Top-off in progress
Charge Status
Battery absent
Fast charge pending or discharge-before-charge in progress
Fast charge in progress
Fast charge complete, top-off, and/or trickle
TM1 TM2
TCO
LED1
Low
High
Low
High
LED1
Low
High
Low
High
LED1
Low
Low
Low
High
LED2
Low
High
High
Low
LED2
Low
Low
High
High
LED2
Low
1/8s high
1/8s low
High
Low
LED1
LED2
DSEL
DCMD
DVEN
OSC
Display
Control
Timing
Control
Charge Control
State Machine
Discharge
Control
MOD
Control
TCO
Check
LTF
Check
VTS - VSNS
VBAT - VSNS ^A/D
EDV
Check
PWR
Control
MCV
Check
TS
SNS
BAT
DIS
MOD
INH
VCC VSS
Figure 3. Block Diagram
BD200401.eps
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