BQ24735_17 Datasheet, PDF (32/46 Pages) Texas Instruments – 1- to 4-Cell Li+ Battery SMBus Charge Controller for Supporting Turbo Boost Mode With N-Channel Power MOSFET Selector

bq24735
SLUSAK9B – SEPTEMBER 2011 – REVISED APRIL 2015
www.ti.com
In normal operation, the low-side MOSFET current is from source to drain which generates a negative voltage
drop when it turns on. As a result, the overcurrent comparator cannot be triggered. When the high-side switch
short circuit or inductor short circuit occurs, the large current of the low-side MOSFET is from drain to source and
can trigger the low-side switch overcurrent comparator. bq24735 senses the low-side switch voltage drop through
the PHASE pin and the GND pin.
The high-side FET short is detected by monitoring the voltage drop between ACP and PHASE. As a result, it not
only monitors the high-side switch voltage drop, but also the adapter-sensing resistor voltage drop and PCB
trace voltage drop from the ACN terminal of R_AC to the charger high-side switch drain. Usually, there is a long
trance between input-sensing resistor and charger-converting input, a careful layout will minimize the trace effect.
Table 8. Component List for Typical System Circuit of Figure 16
PART DESIGNATOR
C1, C2, C3, C13, C14, C16
C4
C5, C6
C7
C8, C9, C10, C11
C15
C17
Ci
Csys
D1
D2
Q1, Q2, Q5
Q3, Q4
Q6
L1
R1
R2
R3, R4, R5
R6, R10, R11
R7
R8
R9
R12
R13
R14
R15
RAC, RSR
Ri
U1
U2
QTY
6
1
2
1
4
1
1
1
1
1
1
3
2
1
1
1
1
3
3
1
1
1
1
1
1
1
2
1
1
1
DESCRIPTION
Capacitor, Ceramic, 0.1 µF, 25 V, 10%, X7R, 0603
Capacitor, Ceramic, 100 pF, 25 V, 10%, X7R, 0603
Capacitor, Ceramic, 1 µF, 25 V, 10%, X7R, 0603
Capacitor, Ceramic, 0.047 µF, 25 V, 10%, X7R, 0603
Capacitor, Ceramic, 10 µF, 25 V, 10%, X7R, 1206
Capacitor, Ceramic, 0.01 µF, 25 V, 10%, X7R, 0603
Capacitor, Ceramic, 2200 pF, 25 V, 10%, X7R, 0603
Capacitor, Ceramic, 2.2 µF, 25 V, 10%, X7R, 1210
Capacitor, Electrolytic, 220 µF, 25 V
Diode, Schottky, 30 V, 200 mA, SOT-23, Fairchild, BAT54
Diode, Dual Schottky, 30 V, 200 mA, SOT-23, Fairchild, BAT54C
N-channel MOSFET, 30 V, 12.5 A, SO-8, Fairchild, FDS6680A
N-channel MOSFET, 30 V, 12 A, PowerPAK 1212-8, Vishay Siliconix, SiS412DN
N-channel MOSFET, 50 V, 0.2 A, SOT-323, Diodes, BSS138W
Inductor, SMT, 4.7 µH, 5.5 A, Vishay Dale, IHLP2525CZER4R7M01
Resistor, Chip, 430 kΩ, 1/10 W, 1%, 0603
Resistor, Chip, 66.5 kΩ, 1/10 W, 1%, 0603
Resistor, Chip, 10 kΩ, 1/10 W, 1%, 0603
Resistor, Chip, 4.02 kΩ, 1/10 W, 1%, 0603
Resistor, Chip, 316 kΩ, 1/10 W, 1%, 0603
Resistor, Chip, 100 kΩ, 1/10 W, 1%, 0603
Resistor, Chip, 10 Ω, 1/4 W, 1%, 1206
Resistor, Chip, 1.00 MΩ, 1/10 W, 1%, 0603
Resistor, Chip, 3.01 MΩ, 1/10 W, 1%, 0603
Resistor, Chip, 10 Ω, 1/10 W, 5%, 0603
Resistor, Chip, 7.5 Ω, 1/10 W, 5%, 0603
Resistor, Chip, 0.01 Ω, 1/2 W, 1%, 1206
Resistor, Chip, 2 Ω, 1/2 W, 1%, 1210
Charger controller, 20-pin VQFN, TI, bq24735RGR
Dual digital transistor, 40 V, 30 mA, SC-74, Rohm, IMD2A
32
Submit Documentation Feedback
Product Folder Links: bq24735
Copyright © 2011–2015, Texas Instruments Incorporated