BQ24742 Datasheet, PDF (22/35 Pages) Texas Instruments – Li-Ion or Li-Polymer Battery Charger with Low Iq and Accurate Trickle Charge

bq24741, bq24742
SLUS875B – MARCH 2009 – REVISED OCTOBER 2009
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Status Outputs ( EXTPWR , LPMOD , DPMDET Pin)
Three status outputs are available, and they all require external pull up resistors to pull the pins to system digital
rail for a high level.
EXTPWR open-drain output goes low under each of the three conditions:
1. ACDET is above 2.4 V
2. Adapter current is above 1.25 A using a 10mohm sense resistor (IADAPT voltage above 250 mV)
Internally, the AC current detect comparator looks between the output of the 20x adapter current amplifier and an
internal 250mV threshold. EXTPWR indicates a good adapter is connected because of valid voltage or current.
LPMOD output goes low when the input current is higher than the programmed threshold via LPREF pin.
Hysteresis is internally set to 6% of the programmed LPMOD threshold.
DPMDET open-drain output goes low when the DPM loop is active to reduce the battery charge current.
Table 4. Component List for Typical System Circuit of Figure 1
PART DESIGNATOR
Q1, Q2, Q3
Q4
D1, D2
R_AC
R_SR
L1
C1
C6, C7, C11, C12
C4, C10
C13
C2, C3, C8, C9, C13, C14, C15, C16
C5
R1
R2
R3, R4, R5, R15
R6
R7
R8
R9
R10
R11
R12
R13
R14
QTY
3
1
2
1
1
1
1
4
2
1
6
1
1
1
4
1
1
1
1
1
1
1
1
1
DESCRIPTION
P-channel MOSFET, -30V,-6A, SO-8, Vishay-Siliconix, Si4435
N-channel Dual-MOSFET, 30V, 7.5A, SO-8, Fairchild, FDS8978
Diode, Dual Schottky, 30V, 200mA, SOT23, Fairchild, BAT54C
Sense Resistor, 10mΩ, 1%, 1W, 2010, Vishay-Dale, WSL2010R0100F
Sense Resistor, 20mΩ, 1%, 1W, 2010, Vishay-Dale, WSL2010R0200F
Inductor, 10μH, 24.8mΩ Vishay-Dale, IHLP5050CE-01
Capacitor, Ceramic, 2.2μF, 35V, 20%, X5R, 1206, Panasonic, ECJ-3YB1E225M
Capacitor, Ceramic, 10μF, 35V, 20%, X5R, 1206, Panasonic, ECJ-3YB1E106M
Capacitor, Ceramic, 1μF, 25V, 10%, X7R, 2012, TDK, C2012X7R1E105K
Capacitor, Ceramic, 100nF, 25V, 10%, X7R, 0805, Kemet, C0805C104K5RACTU
Capacitor, Ceramic, 0.1μF, 50V, 10%, X7R, 0805, Kemet, C0805C104K5RACTU
Capacitor, Ceramic, 100pF, 25V, 10%, X7R, 0805, Kemet, C0805C101K5RACTU
Resistor, Chip, 464kΩ, 1/16W, 1%, 0402
Resistor, Chip, 66.5kΩ, 1/16W, 1%, 0402
Resistor, Chip, 10kΩ, 1/16W, 5%, 0402
Resistor, Chip, 97.6kΩ, 1/16W, 1%, 0402
Resistor, Chip, 73.2kΩ, 1/16W, 1%, 0402
Resistor, Chip, 26.7kΩ, 1/16W, 1%, 0402
Resistor, Chip, 60.4kΩ, 1/16W, 1%, 0402
Resistor, Chip, 40.2kΩ, 1/16W, 1%, 0402
Resistor, Chip, 2Ω, 1W, 5%, 2012
Resistor, Chip, 102kΩ, 1/16W, 1%, 0402
Resistor, Chip, 64.9kΩ, 1/16W, 1%, 0402
Resistor, Chip, 120kΩ, 1/16W, 1%, 0402
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