Datasheet

Background
1-2
1.1 Background
The bq24001/2/3/7 series ICs are advanced Li-Ion linear charge management
devices for highly integrated and space-limited applications. They combine
high-accuracy current and voltage regulation; FET pass-transistor and
reverse-blocking Schottky; battery conditioning, temperature, or input-power
monitoring; charge termination; charge-status indication; and charge timer in
a small, 20-lead RGW package.
The bq24001/2/3/7 continuously measures battery temperature using an
external thermistor. For safety reasons, the bq24001/2/3/7 inhibits charge until
the battery temperature is within the user-defined thresholds. Alternatively, the
user can monitor the input voltage to qualify charge. The bq24001/2/3/7 series
then charge the battery in three phases: preconditioning, constant current, and
constant voltage. If the battery voltage is below the internal low-voltage
threshold, the bq24001/2/3/7 uses trickle-charge to condition the battery. A
preconditioning timer is provided for additional safety. Following
preconditioning, the bq24001/2/3/7 applies a constant-charge current to the
battery. An external sense-resistor sets the magnitude of the current. The
constant-current phase is maintained until the battery reaches the
charge-regulation voltage. The bq24001/2/3/7 then transitions to the constant
voltage phase. The user can configure the device for cells with either coke or
graphite anodes.
Charge is terminated by either of the following methods:
- Maximum time
- Minimum current detection plus 23-minute timeout
- Termination can be disabled on the bq24007 IC (disables hour/s timer)
1.2 Performance Specification Summary
This section summarizes the performance specifications of the bq24001/2/3/7
EVM. Table 1–1 gives the performance specifications of the hubs.
The bq24001/2/3/7 automatically restarts the charge if the battery voltage falls
below an internal recharge threshold.
Table 1–1.Performance Specification Summary (One Cell)
Specification Test Conditions Min Typ Max Units
Input dc voltage, V
I
4.9 5.0 † V
Battery charge current 0.9 1 1.1 A
Battery voltage regulation
J6 set to V
CC
4.15 4.20 4.25
V
B
attery vo
l
tage regu
l
at
i
on
J6 set to GND 4.05 4.1 4.15
V
Therm fault
High, T
(BATMAX)
J2 set to Therm 43 48 53
°
C
Th
erm
f
au
l
t
Low, T
(BATMIN)
J2 set to Therm 0 5 10
°
C
APG (user defined, see data sheet) J2 set to APG ‡
Power dissipation, P
D
(V
I
-V
O
) × I
load
2.3 W
†
V
I
, for a single-cell, should not exceed 5.3 VDC for the 1-A charge rate and 7.6 V for the 0.5-A charge rate. (V
I
is the input voltage
to the bq24001 IC, pins 2 and 3. The power supply source voltage, at J1, is 0.1 V larger than V
I
because of the regulated voltage
drop across the current sense resistor, during constant current regulation.)
‡
If J2 is set to APG, then the chip is pending when the input is outside of this range: 3.0 V–7.7 V.