Battery monitoring functions

AN3064

8/15

Doc ID 16263 Rev 1

The counter code is an unsigned 16-bit binary number.

wraps to 0 and continues counting. Both the accumulator and the counter can be reset with

the GG_RST bit.

The CG_EOC bit in the REG_CTRL register can be used to check that at least one new

current measurement has been done and accumulated since the last reading of the

REG_CTRL register.

2.3

Battery current reading

The last measured value of the current is available in the REG_CURRENT locations (two

bytes) and is updated at each conversion.

The current code is a 14-bit binary number using the two’s complement binary format. Bit 13

is the sign bit and bits 0 to 12 are the data bits. The LSB value (bit 0) is 11.77 µV.h,

irrespective of the current conversion resolution. However, bit 0 is always zero in 12- and 13-

bit resolution modes, and bit 1 is always zero in 12-bit resolution mode. To convert the

current data into mA, the external resistance Rsense must be taken into account.

current (mA) = current_code* 11.77 / Rsense (m

Ω)

Table 3.

REG_COUNTER_LOW. address 4 (04h)

Name

Pos.

Type

Power-

up

Description

DATA[7..0]

[7..0]

R

00

Conversion counter data.

Table 4.

REG_COUNTER_HIGH. address 5 (05h)

Name

Pos.

Type

Power-up

Description

DATA[15..8]

[7..0]

R

00

Conversion counter data

Table 5.

REG_CURRENT_LOW. address 6 (06h)

Name

Pos.

Type

Power-up

Description

DATA[7..0]

[7..0]

R

00

Battery current data

Table 6.

REG_CURRENT_HIGH. address 7 (07h)

Name

Pos.

Type

Power-up

Description

DATA[13..8]

[5..0]

R

00

Battery current data

DATA[15, 14]

[7,6]

R

0

Unused