BQ24195 Datasheet, PDF (17/41 Pages) Texas Instruments – I2C Controlled 2.5A / 4.5A Single Cell USB/Adapter Charger With 5.1V at 1A / 5.1V at 2.1A Synchronous Boost Operation

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bq24195
bq24195L
SLUSB97 – OCTOBER 2012
Vender / Part / Revision Status Register REG0A
BIT
DESCRIPTION
Bit 7
Reserved
0 - Reserved
Bit 6
Reserved
0 - Reserved
Device Configuration
Bit 5
PN[2]
100
Bit 4
PN[1]
Bit 3
PN[0]
Bit 2
TS_PROFILE
0 - Cold/Hot window
Bit 1
DEV_REG[0]
11
Bit 0
DEV_REG[1]
DETAILED DESCRIPTION
The bq24195L, bq24195 is an I²C controlled power path management device and a single cell Li-Ion battery
charger. It integrates the input reverse-blocking FET (RBFET, Q1), high-side switching FET (HSFET, Q2), low-
side switching FET (LSFET, Q3), and BATFET (Q4) between system and battery. The device also integrates the
bootstrap diode for the high-side gate drive.
Device Power Up
Power-On-Reset (POR)
The internal bias circuits are powered from the higher voltage of VBUS and BAT. When VBUS or VBAT rises
above UVLOZ, the sleep comparator, battery depletion comparator and BATFET driver are active. I²C interface
is ready for communication and all the registers are reset to default value. The host can access all the registers
after POR.
Power Up from Battery without DC Source
If only battery is present and the voltage is above depletion threshold (V_{BAT_DEPL}), the BATFET turns on and
connects battery to system. The REGN LDO stays off to minimize the quiescent current. The low R_DSON in
BATFET and the low quiescent current on BAT minimize the conduction loss and maximize the battery run time.
The device always monitors the discharge current through BATFET. When the system is overloaded or shorted,
the device will immediately turn off BATFET and keep BATFET off until the input source plugs in again.
BATFET Turn Off
The BATFET can be forced off by the host through I²C REG07[5]. This bit allows the user to independently turn
off the BATFET when the battery condition becomes abnormal during charging. When BATFET is off, there is no
path to charge or discharge the battery.
When battery is not attached, the BATFET should be turned off by setting REG07[5] to 1 to disable charging and
supplement mode.
Shipping Mode
When end equipment is assembled, the system is connected to battery through BATFET. There will be a small
leakage current to discharge the battery even when the system is powered off. In order to extend the battery life
during shipping and storage, the device can turn off BATFET so that the system voltage is zero to minimize the
leakage.
In order to keep BATFET off during shipping mode, the host has to disable the watchdog timer (REG05[5:4]=00)
and disable BATFET (REG07[5]=1) at the same time.
Once the BATFET is disabled, the BATFET can be turned on by plugging in adapter.
Copyright © 2012, Texas Instruments Incorporated
Product Folder Links: bq24195 bq24195L
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