Datasheet

0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
0.6
1.8
V -Voltage-V
TS
NormalizedOUTCurrentandV -V
REG
60 Cto45 C
HOT TEMP
4.06V
Regulation
o o
I
OUT
V
OUT
0
0.2
0.4
0.8
1
1.2
1.4
1.6
For<45 C,4.2VRegulation
o
} HotFault
NoOperation
DuringCold
Fault
Cold
Fault
ICDisable}
0 C
o
< 48 C
o
60 C
o
10 C
o
100%ofProgrammed
Current
50%
Termination
Disable
bq24050
bq24052
bq24055
www.ti.com SLUS940B –SEPTEMBER 2009–REVISED JUNE 2012
ISET
An external resistor is used to Program the Output Current (50 to 800mA) and can be used as a current monitor.
R
ISET
= K
ISET
÷ I
OUT
(0)
Where:
I
OUT
is the desired fast charge current;
K
ISET
is a gain factor found in the electrical specification
For greater accuracy at lower currents, part of the sense FET is disabled to give better resolution. Figure 19
shows the transition from low current to higher current. Going from higher currents to low currents, there is
hysteresis and the transition occurs around 0.15A.
The ISET resistor is short protected and will detect a resistance lower than ≉340Ω. The detection requires at
least 80mA of output current. If a “short” is detected, then the IC will latch off and can only be reset by cycling the
power. The OUT current is internally clamped to a maximum current between 1.1A and 1.35A and is independent
of the ISET short detection circuitry, as shown in Figure 27. Also, see Figure 13 and Figure 14.
Figure 26. OPERATION OVER TS BIAS VOLTAGE
Copyright © 2009–2012, Texas Instruments Incorporated 21