bq2005
Pin Descriptions
DCMD
A
Discharge-before-charge control input,
battery A
DCMD
A
controls the discharge-before-charge
function of the bq2005. A negative-going
pulse on DCMD
A
initiates a discharge to
EDV followed by a charge if conditions allow.
By tying DCMD
A
to ground, automatic
discharge-before-charge is enabled on every
new charge cycle start.
DVEN
-∆V enable input
This input enales/disables -∆V charge termina-
tion. If DVEN is high, the -∆V test is enabled.
If DVEN is low, -∆V test is disabled. The state
of DVEN may be changed at any time.
TM
1
–
TM
2
Timer mode inputs
TM
1
and TM
2
are three-state inputs that con-
figure the fast charge safety timer, -∆V hold-
off time, and that enhance/disable top-off.
See Table 2.
TCO
Temperature cutoff threshold input
Input to set maximum allowable battery
temperature. If the potential between TS
A
and SNS
A
or TSB and SNS
B
is less than the
voltage at the TCO input, then fast charge or
top-off charge is terminated for the corre-
sponding battery pack.
TS
A
,
TS
B
Temperature sense inputs
Input, referenced to SNS
A
or SNS
B,
respec-
tively, for an external thermistor monitoring
battery temperature.
BAT
A
,
BAT
B
Voltage inputs
The battery voltage sense input, referenced to
SNS
A,B
, respectively. This is created by a
high-impedance resistor divider network con-
nected between the positive and the negative
terminals of the battery.
SNS
A
,
SNS
B
Charging current sense inputs,
SNS
A,B
controls the switching of MOD
A,B
based on the voltage across an external
sense resistor in the current path of the bat-
tery. SNS is the reference potential for the
TS and BAT pins. If SNS is connected to
V
SS
, MOD switches high at the beginning of
charge and low at the end of charge.
V
CC
CH
A
,
CH
B
DIS
A
Discharge control output
Push-pull output used to control an external
transistor to discharge battery A before
charging.
Charge status outputs
Push-pull outputs indicating charging status
for batteries A and B, respectively. See Fig-
ure 1 and Table 2.
FCC
A
,
FCC
B
Fast charge complete outputs
Open-drain outputs indicating fast charge
complete for batteries A and B, respectively.
See Figure 1 and Table 2.
MOD
A
,
MOD
B
Charge current control outputs
MOD
A,B
is a push-pull output that is used to
control the charging current to the battery.
MOD
A,B
switches high to enable charging
current to flow and low to inhibit charging
c u r r en t f low t o ba t te ri es A a n d B,
respectively.
V
CC
supply input
5.0 V, ±10% power input.
Vss
Ground
2
TI [ TEXAS INSTRUMENTS ]
