BQ27546-G1 Datasheet, PDF (18/38 Pages) Texas Instruments – nullSingle-Cell Li-Ion Battery Fuel Gauge

bq27546-G1
SLUSC53A – MAY 2015 – REVISED DECEMBER 2015
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Device Functional Modes (continued)
9.4.2 System Control Function
The fuel gauge provides system control functions that allow the fuel gauge to enter SHUTDOWN mode in order
to power-off with the assistance of an external circuit or provide interrupt function to the system. Table 2 shows
the configurations for SE and HDQ pins.
Table 2. SE and HDQ Pin Functions
[INTSEL]
0 (default)
1
COMMUNICATION
MODE
I²C
HDQ
I²C
HDQ
SE PIN FUNCTION
Interrupt Mode ⁽¹⁾
Shutdown Mode
HDQ PIN FUNCTION
Not Used
HDQ Mode⁽²⁾
Interrupt Mode
HDQ Mode⁽²⁾
(1) The [SE_EN] bit in Pack Configuration can be enabled to use the [SE] and [SHUTDWN] bits in the
CONTROL_STATUS() function. The SE pin shutdown function is disabled.
(2) The HDQ pin is used for communication and the HDQ Host Interrupt Feature is available.
9.4.2.1 SHUTDOWN Mode
In SHUTDOWN mode, the SE pin is used to signal the external circuit to power-off the fuel gauge. This feature is
useful to shut down the fuel gauge in a deeply discharged battery to protect the battery. By default, SHUTDOWN
mode is in NORMAL state. By sending the SET_SHUTDOWN subcommand or setting the [SE_EN] bit in the
Pack Configuration register, the [SHUTDWN] bit is set and enables the shutdown feature. When this feature is
enabled and [INTSEL] is set, the SE pin can be in NORMAL state or SHUTDOWN state. The SHUTDOWN state
can be entered in HIBERNATE mode (only if HIBERNATE mode is enabled due to low cell voltage). All other
power modes will default the SE pin to NORMAL state. Table 3 shows the SE pin state in NORMAL or
SHUTDOWN mode. The CLEAR_SHUTDOWN subcommand or clearing [SE_EN] bit in the Pack Configuration
register can be used to disable SHUTDOWN mode.
The SE pin will be high impedance at power-on reset (POR), and the [SE_POL] does not affect the state of SE
pin at POR. Also, [SE_PU] configuration changes will only take effect after POR. In addition, the [INTSEL] only
controls the behavior of the SE pin; it does not affect the function of [SE] and [SHUTDWN] bits.
Table 3. SE Pin State
[SE_PU]
0
0
1
1
[SE_POL]
0
1
0
1
SHUTDOWN Mode
[INTSEL] = 1 and
([SE_EN] or [SHUTDOWN] = 1)
NORMAL State
SHUTDOWN State
High Impedance
0
0
High Impedance
1
0
0
1
9.4.2.2 INTERRUPT Mode
By using the INTERRUPT mode, the system can be interrupted based on detected fault conditions, as specified
in Table 6. The SE or HDQ pin can be selected as the interrupt pin by configuring the [INTSEL] bit based on . In
addition, the pin polarity and pullup (SE pin only) can be configured according to the system's needs, as
described in Table 4 or Table 5.
[SE_PU]
0
0
1
1
Table 4. SE Pin in Interrupt Mode ([INTSEL] = 0)
[INTPOL]
0
1
0
1
INTERRUPT CLEAR
High Impedance
0
1
0
INTERRUPT SET
0
High Impedance
0
1
18
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