BQ24721 Datasheet, PDF (7/48 Pages) Texas Instruments – ADVANCED MULTI-CHEMISTRY AND MULTI-CELL SYNCHRONOUS SWITCH-MODE CHARGER AND SYSTEM POWER SELECTOR

bq24721
www.ti.com
SLUS683 – NOVEMBER 2005
ELECTRICAL CHARACTERISTICS
8 Vdc ≤ V_(VCC) ≤ 24 Vdc, 0°C ≤ T_J ≤ 125°C, all voltages with respect to AGND (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
SYSTEM STATUS COMPARATORS INPUT SPECIFICATIONS
Commom mode input range at
pin: ACDET
0
V_ICR
Commom mode input range at
TS pin
0.5
Common mode input voltage
range at pins: BAT, SYS
0
I_(bias)
Input bias currents at pins:
ACDET, TS, BATDEP, SYS
BATTERY DEPLETED COMPARATOR (BATDEP)
V_(BATDEP) = 2.2 V + Vstep × batdep_dac_code, where
batdep_dac_code = 0 - 7, and Vstep = 0.1V, SMBus Charge Mode
V_(BATDEP)
BAT depleted voltage range
register 0×12, bits b9, b10, b11
For programmed V_(BATREG) = 9 V, then cell = 2
2.2
For programmed V_(BATREG) = 12 V - 14.4 V, then cell = 3
For programmed V_(BATREG) = 16 V - 19.2 V, then cel l= 4
BAT depleted accuracy
-2
Battery depleted detection
deglitch time
V_(BAT) falling
Battery not depleted detection
deglitch time
V_(BAT) rising
AC ADAPTER DETECT COMPARATOR (ACDET)
V_(ACD)
AC adapter detect threshold
V_(ACDET) rising, When adapter detected, VREF5 is enabled, and
REGN regulates to 6 V
1.176
V_(ACDH)
AC adapter detect hysteresis
AC adapter detected deglitch
time
V_(ACDET) falling
V_(ACDET) rising
AC adapter not detected
deglitch time
V_(ACDET) falling
AC ADAPTER (ACP) - BATTERY (BAT) COMPARATOR
V_(ACP-BAT)
ACP voltage above BAT voltage
threshold
V_(ACP) falling with respect to V_(BAT)
V_(ACP-
BAT)HYS
Hysteresis
V_(ACP-BAT) falling below
threshold deglitch time
V_(ACP-BAT) rising with respect to V_(BAT)
V_(ACP) falling with respect to V_(BAT)
V_(ACP-BAT) rising above
thresholddeglitch time
V_(ACP-BAT) rising with respect to V_(BAT)
SYSTEM (SYS) - BATTERY (BAT) COMPARATOR
V_(SYS-BAT)
System voltage above pack
voltage at V_(VS,BAT) > V_(SYS)
V_(SYS-BAT)HYS Hysteresis
V_(SYS-BAT) falling below
threshold deglitch time
V_(SYS) falling with respect to V_(BAT)
V_(SYS-BAT) rising with respect to V_(BAT)
V_(SYS) falling with respect to V_(BAT)
V_(SYS-BAT) rising above
thresholddeglitch time
V_(SYS-BAT) rising with respect to V_(BAT)
BATTERY SHORTED COMPARATOR
V_(BATSHORT) Battery shorted threshold⁽¹⁾
V_{(SHRT_HYS))} Hysteresis
Battery shorted deglitch time
V_(BAT) falling,
Programmed V_(BAT) = 9V
V_(BAT) falling,
Programmed V_(BAT) = 12-14.4V
V_(BAT) falling,
Programmed V_(BAT) = 16-19.2V
V_(BAT) rising
V_(BAT) rising/falling
3.230
4.845
6.460
TYP MAX UNIT
5
V
VREF5
V
VCC
V
0.2 µA
2.9 V/cell
2%
1
s
1
s
1.2 1.224
V
15
mV
8
ms
1
µs
250
300 mV
50
mV
16
µs
8
ms
250
300 mV
50
mV
1
µs
8
ms
3.4 3.570
V
5.1 5.355
V
6.8 7.140
V
200
mV/cell
1
s
(1) For the bq24721: When BAT falls below the V_(BATSHORT) threshold, the charger continues regulating at the programmed current down to
zero volts on BAT; then after 1 second deglitch time, the charge current automatically changes to 1/8 the programmed charge current.
The charge current automatically changes from 1/8 the programmed charge current to the full programmed charge current when BAT
voltage rises above (V_(BATSHORT) + 200 mV hysteresis), after 1 second deglitch time.
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