BQ24702_16 Datasheet, PDF (2/37 Pages) Texas Instruments – MULTICHEMISTRY BATTERY CHARGER CONTROLLER

bq24702
bq24703
SLUS553E – MAY 2003 – REVISED OCTOBER 2007
www.ti.com
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
DESCRIPTION (CONTINUED)
The battery voltage limit can be programmed by using the internal 1.196-V, ±0.5% precision reference, making it
suitable for the critical charging demands of lithium-ion cells. Also, the bq24702/bq24703 provides an option to
override the precision reference and drive the error amplifier either directly from an external reference or from a
resistor divider off the 5 V supplied by the integrated circuit.
The selector function allows the manual selection of the system power source, battery or wall-adapter power.
The bq24702/bq24703 supports battery-conditioning and battery-learn cycles through the ACSEL function. The
ACSEL function allows manual selection of the battery or wall power as the main system power. It also provides
autonomous switching to the remaining source (battery or ac power) should the selected system power source
terminate (refer to Available Options table for the differences between the bq24702 and the bq24703). The
bq24702/bq24703 also provides an alarm function to indicate a depleted battery condition.
The bq24702/bq24703 PWM controller is ideally suited for operation in a buck converter for applications when
the wall-adapter voltage is greater than the battery voltage.
DISSIPATION RATINGS
MAXIMUM POWER DISSIPATION
(HIGH K BOARD)
vs
FREE-AIR TEMPERATURE
1.60
MAXIMUM POWER DISSIPATION
(LOW K BOARD)
vs
FREE-AIR TEMPERATURE
1.40
1.40
MAX Pd (W) @ 500 LFM
MAX Pd (W) @ 250 LFM
1.20
MAX Pd (W) @ 150 LFM
MAX Pd (W) @ 0 LFM
1
1.20
MAX Pd (W) @ 500 LFM
MAX Pd (W) @ 250 LFM
1
MAX Pd (W) @ 150 LFM
MAX Pd (W) @ 0 LFM
0.80
0.80
0.60
0.60
0.40
0.40
0.20
θ_JA = 89.37 C/W @ 0 LFM,
θ_JA = 77.98 C/W @ 150 LFM,
θ_JA = 73.93 C/W @ 250 LFM,
θ_JA = 68.23 C/W @ 500 LFM
0.20
θ_JA = 150.17 C/W @ 0 LFM,
θ_JA = 110.95 C/W @ 150 LFM,
θ_JA = 99.81 C/W @ 250 LFM,
θ_JA = 86.03 C/W @ 500 LFM
0
25
50
70
0
85
25
50
70
85
T_A - Free-Air Temperature - °C
T_A - Free-Air Temperature - °C
A. The JEDEC low K (1s) board design used to derive this data was a 3-inch × 3-inch, two layer board with 2 ounce
copper traces on top of the board.
B. The JEDEC high K (1s) board design used to derive this data was a 3-inch × 3-inch, multilayer board with 1 ounce
internal power and ground planes and 2 ounce copper traces on top and bottom of the board.
2
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