FS5908

Rev. 1.2

13/22

And the temperature accuracy of the chip that influenced by the power is shown as below table:

Pav

Influenced Temp. (Δ )

℃

1mW

0.125

5mW

0.625

10mW

1.125

20mW

1.750

13.3 Standby Mode (shutdown=Reg1<0>)

To setup Shutdown bit of control register will enter the Stand-by Mode. In stand-by mode, the standard current

consumption of FS5908 will be lower than 100uA. In interrupt mode, if ALARM enters stand-by mode in action

status, then the action status of ALARM will be clear, but if it enters stand-by mode when in comparison mode,

ALARM will keep the status of before entering. In stand-by mode, all circuits are close except I2C circuit.

13.4 Power Off (CS)

When set CS to 0, then the chip is close, and the current consumption is lower than 5μA.

When set CS to 1 (voltage is VDD), then the chip is enabled, and all status will be default operations. Please

see below diagram for the description of default status.

Take the chip as Watchdog (independent temperature sensor).

SCL: connect to ground

SDA: floating

CS: connect to VDD

A0:

connect to ground or VDD

Please see the diagram on page 3: Application I

13.5 set_arm_cnt (Reg 1<4:3>)

Inside the chip, every record of measuring temperature will be updated per 1/4 second. When the measuring

temperature reaches the warning temperature, the inner warning counter will increase counting, and only when

the value of the warning counter is equal to the setup times in set_arm_cnt, ALARM pin will send out the

warning signal. During the process, any record of measuring temperature that not reach the warning

temperature will make the system clear the warning counter to be 0 so that the proper setup for set_arm_cnt

can avoid noise or interfere making ALARM to act error.

set_arm_cnt<1:0>

Necessary compare output times to make ALARM output change

00

1 (Default)

01

2

10

4

11

8

13.6 Low Battery Detection (setlowbat=Reg1<7>)

setlowbat

0

1

=1

=1

Rog0<14>=lowbat

@VDD

Ρ2.4V

@VDD

Ρ2.2V