Datasheet

bq24270
bq24271
www.ti.com SLUSB10 –JUNE 2012
Battery and Supply Status Register (READ/WRITE)
Memory location: 01, Reset state: xxxx 0xxx
BIT NAME Read/Write FUNCTION
B7(MSB) NA Read Only NA
B6 NA Read Only NA
B5 USBSTAT1 Read Only 00-Normal
01-Supply OVP
01-Weak Source Connected (No Charging)
B4 USBSTAT0 Read Only
11- V
USB
< V
UVLO
0 – No OTG supply present. Use USB input as normal.
B3 OTG_LOCK Read/Write 1 – OTG supply present. Lockout USB input for charging.
(default 0)
B2 BATSTAT1 Read Only 00-Battery Present and Normal
01-Battery OVP
10-Battery Not Present
B1 BATSTAT0 Read Only
11- NA
0-Normal Operation
B0 (LSB) EN_NOBATOP Read/ Write 1-Enables No Battery Operation when termination is disabled
(default 0)
OTG_LOCK Bit (USB Lockout)
The OTG_LOCK bit is used to prevent any charging from USB. For systems using OTG supplies, it is not
desirable to charge from an OTG source. Doing so would mean draining the battery by allowing it to effectively
charge itself. Write a “1” to OTG_LOCK to lock out the USB input. Write a “0” to OTG_LOCK to return to normal
operation. The watchdog timer must be reset while in USB_LOCK to maintain the USB lockout state. This
prevents the USB input from being permanently locked out for cases where the host loses I
2
C communication
with OTG_LOCK set (i.e. discharged battery from OTG operation). See the Safety Timer and Watchdog Timer
section for more details.
EN_NOBATOP (No Battery Operation with Termination Disabled
The EN_NOBATOP bit is used to enable operation when termination is disabled and no battery is connected.
This is useful for cases where the PA is connected to the BAT pin and it desired to do a calibration in the factory.
For this application, the TE bit (Bit 2 in Register 0x02h) should be set to a “0” to disable termination and the
EN_NOBATOP should be set to a “1”. This feature should not be used during normal operation as it disables the
BATOVP and the reverse boost protection circuits.
Control Register (READ/WRITE)
Memory location: 02, Reset state: 1000 1100
BIT NAME Read/Write FUNCTION
Write: 1-Reset all registers to default values
B7(MSB) RESET Write only 0-No effect
Read: always get “1”
B6 IUSB_LIMIT_2 Read/Write 000-USB2.0 host with 100mA current limit
001-USB3.0 host with 150mA current limit
B5 IUSB_LIMIT_1 Read/Write
010 – USB2.0 host with 500mA current limit
011 – USB host/charger with 800mA current limit
100 – USB3.0 host with 900mA current limit
B4 IUSB_LIMIT _0 Read/Write
101 – USB host/charger with 1500mA current limit
110 -111 – NA (default 000(1))
1-Enable STAT output to show charge status,
B3 EN_STAT Read/Write 0-Disable STAT output for charge status. Fault interrupts are still show even
when EN_STAT = 0. (default 1)
1-Enable charge current termination, 0-Disable charge current termination
B2 TE Read/Write
(default 1)
1-Charger is disabled
B1 CE Read/Write
0-Charger enabled (default 0)
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