BQ24751B Datasheet, PDF (8/38 Pages) Texas Instruments – Host-Controlled Multi-Chemistry Battery Charger with Low Iq and System Power Selector

Not Recommended For New Designs
bq24751B
SLUS835A – JULY 2008 – REVISED MARCH 2009 .......................................................................................................................................................... www.ti.com
ELECTRICAL CHARACTERISTICS (continued)
7 V ≤ V_PVCC ≤ 24 V, 0°C < T_J < 125°C, typical values are at T_A = 25°C, with respect to AGND (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN TYP MAX UNIT
BAT SHORT (UNDERVOLTAGE) COMPARATOR
V_{BAT_SHORT_FALL}
V_{BAT_SHORT_HYS}
BAT short falling threshold
BAT short hysteresis
BAT short rising deglitch
BAT short falling deglitch
BATSHORT EXIT delay to turn on
BATFET and turn off ACFET
V_BAT falling
V_BAT rising
V_BAT > V_{BAT_SHORT}+V_{BAT_SHORT_HYS}
Detection delay
V_BAT < V_{BAT_SHORT}
LEARN=HIGH
2.755
2.9 3.045
250
1.5
1.5
600
V/cell
mV/cell
s
ms
BATSHORT ENTRY delay to turn off
BATFET and turn on ACFET
LEARN=HIGH
10
µs
CHARGE OVERCURRENT COMPARATOR
V_OC
OCP Floor
Charge overcurrent falling threshold
Minimum current Limit (SRP-SRN)
As percentage of I_{REG_CHG}
145%
50
mV
OCP Threshold
falling threshold
rising threshold
0.1xSRSET/VDAC falling
0.1xSRSET/VDAC rising
33.75
mV
42.5
mV
CHARGE UNDERCURRENT COMPARATOR (SYNCHRONOUS TO NON-SYNCHRONOUS TRANSITION)
V_{ISYNSET_FALL}
V_{ISYNSET_HYS}
Charge undercurrent falling threshold
Charge undercurrent rising hysteresis
Charge undercurrent, falling-current
deglitch
Charge undercurrent, rising-current
deglitch
Changing from synchronous to non-sysnchronous
V_{IREG_DPM} < V_ISYNSET
9.75 13 16.25
mV
8
mV
20
µs
640
INPUT OVERPOWER COMPARATOR (ACOP)
V_ACOC
ACOC Gain for initial ACOC current
limit limit (Percentage of programmed
VIREG_DPM)
Begins 700 ms after ACDET,
Input current limited to this threshold for fault
protection
150
%
V_{IREG_DPM}
V_{ACOC_CEILING}
Maximum ACOC input current limit
(V_ACP–V_ACN)max
ACOP Latch Blankout Time with ACOC
active
(begins 700 ms after ACDET)
Internally limited ceiling,
V_{ACOC_MAX} = (V_ACP–V_ACN)max
Begins 700 ms after ACDET
(does not allow ACOP latch-off, and no ACOP
source current)
100
mV
2
ms
V_ACOP
ACOP pin latch-off threshold voltage
(See ACOP in Terminal Functions
table)
1.95
2 2.05
V
K_ACOP
I_{ACOP_SINK}
Gain for ACOP Source Current when in
ACOC
ACOP Sink Current when not in ACOC
ACOP Latch is reset by going below
ACDET or UVLO
Current source on when in ACOC limit. Function of
voltage across power FET
I_{ACOP_SOURCE} = K_ACOP ×(V_PVCC -V_ACP)
Current sink on when not in ACOC
18
µA / V
5
µA
V_ACN-SHORT
ACN Short protection threshold latching ACN < 2.4 V, ACDET > 2.4 V
INPUT OVERVOLTAGE COMPARATOR (ACOV)
2.4
V
V_ACOV
AC Overvoltage rising threshold on
OVPSET
(See OVPSET in Table 1)
Measured on OVPSET
3.007 3.1 3.193
V
V_{ACOV_HYS}
AC Overvoltage rising deglitch
AC Overvoltage falling deglitch
1.3
ms
1.3
THERMAL SHUTDOWN COMPARATOR
T_SHUT
Thermal shutdown rising temperature
T_{SHUT_HYS}
Thermal shutdown hysteresis, falling
BATTERY SWITCH (BATDRV) DRIVER
Temperature Increasing
155
°C
20
°C
R_{DS(off)_BAT}
R_{DS(on)_BAT}
V_{/BATDRV_REG}
BATFET Turn-off resistance
BATFET Turn-on resistance
BATFET drive voltage
BATFET Power-up delay
V_ACN > 5 V
160
Ω
V_ACN > 5 V
3
kΩ
V_{/BATDRV_REG} = V_ACN – V_BATDRV when
V_ACN > 5 V and BATFET is on
6.5
V
Delay to turn off BATFET after adapter is detected
(after V_ACDET > 2.4 V)
518 700
908
ms
8
Submit Documentation Feedback
Product Folder Link(s) :bq24751B
Copyright © 2008–2009, Texas Instruments Incorporated