Texas Instruments bq24013 - Manual (Page 10)

I/O and Jumper Connections
2-2
2.1 I/O and Jumper Connections
Jack Connect To:
J1–DC+ Power supply positive, preset to 5.0VDC, 1-A current limit
J1–DC– Power supply ground
J2–BAT+ Positive battery pack terminal
J2–BAT– Negative battery pack terminal
J2–TTE NC required—pulled down with 10 k
Ω
resistor on EVM
J2–BAT– NC
J3–STAT1 External hardware if J4-EXT is jumpered (not jumpered from factory)
J3–STAT2 External hardware if J5-EXT is jumpered (not jumpered from factory)
J3–DC– Return for J3 signals
J3–/CE NC required—pulled down with 10-k
Ω
resistor on EVM
J4 (Jumper) STAT1 indication location – LED (EVM) | EXT
J5 (Jumper) STAT2 indication location – LED (EVM) | EXT
2.2 Test Procedure
Set up the evaluation board as described above, by making the necessary I/O
connections and jumper selections. Before test and evaluation, it is
important to verify that the maximum power dissipation on the IC is not
exceeded: P
(MAX)
= 1.5 watts.
1) Turn on the power supply, which was preset to 5.0 VDC and 1 A for the
current-limit setting.
2) The bq24013 enters preconditioning mode if the battery is below the
V
(LOWV)
threshold. In this mode, the bq24013 precharges the battery with
a low current (typically I
O(CHG)
/10 = 0.7A/10 = 70 mA) until the battery
voltage reaches the V
(LOWV)
threshold or until the precharge timer
expires. If the timer expires, then the charge current is terminated, the
bq24013 enters fault mode, and both LEDs turn off. Toggling input power
or battery replacement resets fault mode.
3) Once the battery voltage is above the V
(LOWV)
threshold, the battery
enters fast-charge mode. This EVM is programmed for 0.7 A of
fast-charging current.
4) Once the battery reaches voltage regulation (4.2 V), the current tapers
down as the battery reaches its full capacity.
5) The battery remains at the fast-charge mode until the fast-charge timer
expires, the charge taper time expires, or the charge termination threshold
is reached.
6) If the battery discharges to the recharge threshold, the charger starts fast
charging.
In place of a battery, a source meter that can sink current can easily be
adjusted to test each mode.