Datasheet

bq27541-G1

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SLUSAL6C –NOVEMBER 2011–REVISED OCTOBER 2012

SYSTEM CONTROL FUNCTION

The bq27541-G1 provides system control functions which allows the fuel gauge to enter shutdown mode in order

to power-off with the assistance of external circuit or provides interrupt function to the system. Table 16 shows

the configurations for SE and HDQ pins.

Table 16. SE and HDQ Pin Function

COMMUNICATION

[INTSEL] SE PIN FUNCTION HDQ PIN FUNCTION

MODE

I2C Not Used

0 (default) Interrupt Mode

(1)

HDQ HDQ Mode

(2)

I2C Interrupt Mode

1 Shutdown Mode

HDQ HDQ Mode

(2)

(1) [SE_EN] bit in Pack Configuration can be enabled to use [SE] and [SHUTDWN] bits in

CONTROL_STATUS() function; The SE pin shutdown function is disabled.

(2) HDQ pin is used for communication and HDQ Host Interrupt Feature is available.

Shutdown Mode

In the shutdown mode, the SE pin is used to signal external circuit to power-off the fuel gauge. This feature is

useful to shutdown the fuel gauge in a deeply discharged battery to protect the battery. By default, the Shutdown

Mode is in normal state. By sending the SET_SHUTDOWN subcommand or setting the [SE_EN] bit in 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 SE pin to normal state. Table 17 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 bq27541-G1 SE pin will be high impedance at power on reset (POR), 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.

Product Folder Links: bq27541-G1