BQ2010 datasheet(13/26 Pages) TI2

13 / 26 page

The bq2010 calculates the available charge as a function

of NAC, temperature, and a full reference, either LMD

or PFC. The results of the calculation are available via

the display port or the gas gauge field of the TMPGG

in 1

16 increments from 0 to

16.

The gas gauge display and the gas gauge portion of the

TMPGG register are adjusted for cold temperature de-

pendencies. A piece-wise correction is performed as fol-

lows:

The adjustment between > 0°C and -20°C < T < 0°C has

a 10°C hysteresis.

Nominal Available Charge Registers

(NACH/NACL)

The read/write NACH high-byte register (address=03h)

and the read-only NACL low-byte register (address=17h)

are the main gas gauging register for the bq2010. The

NAC registers are incremented during charge actions

and decremented during discharge and self-discharge

actions. The correction factors for charge/discharge effi-

ciency are applied automatically to NAC.

On reset, if PROG6 = Z or low, NACH and NACL are

cleared to 0; if PROG6 = high, NACH = PFC and NACL

= 0. When the bq2010 detects a valid charge, NACL resets

to 0. Writing to the NAC registers affects the available

charge counts and, therefore, affects the bq2010 gas gauge

operation. Do not write the NAC registers to a value greater

than LMD.

Battery Identification Register (BATID)

The read/write BATID register (address=04h) is avail-

able for use by the system to determine the type of bat-

tery pack. The BATID contents are retained as long as

VCC is greater than 2V. The contents of BATID have no

effect on the operation of the bq2010. There is no de-

fault setting for this register.

Last Measured Discharge Register (LMD)

LMD is a read/write register (address=05h) that the

bq2010 uses as a measured full reference. The bq2010

adjusts LMD based on the measured discharge capacity

of the battery from full to empty.

In this way the

bq2010 updates the capacity of the battery. LMD is set

to PFC during a bq2010 reset.

Secondary Status Flags Register (FLGS2)

The read-only FLGS2 register (address=06h) contains

the secondary bq2010 flags.

The charge rate flag (CR) is used to denote the fast

charge regime.

Fast charge is assumed whenever a

charge action is initiated. The CR flag remains asserted

if the charge rate does not fall below 2 counts/sec.

The CR values are:

Where CR is:

When charge rate falls below 2 counts/sec

When charge rate is above 2 counts/sec

The fast charge regime efficiency factors are used when

CR = 1. When CR = 0, the trickle charge efficiency fac-

tors are used. The time to change CR varies due to the

user-selectable count rates.

The discharge rate flags, DR2–0, are bits 6–4.

They are used to determine the current discharge re-

gime as follows:

The overload flag (OVLD) is asserted when a discharge

overload is detected, VSR < -250mV. OVLD remains as-

serted as long as the condition persists and is cleared

0.5 seconds after VSR > -250mV. The overload condition

is used to stop sampling of the battery terminal character-

istics for end-of-discharge determination. Sampling is re-

enabled 0.5 secs after the overload condition is removed.

FLGS2 Bits

3210

DR2

DR1

DR0

DR2

DR1

DR0

VSR (V)

VSR > -150mV

VSR < -150mV

Temperature

Available Capacity Calculation

> 0°C

NAC / “Full Reference”

-20°C < T < 0°C

0.75 * NAC / “Full Reference”

< -20°C

0.5 * NAC / “Full Reference”

TMPGG Gas Gauge Bits

GG3

GG2

GG1

GG0

FLGS2 Bits

OVLD

bq2010

BQ2010 Datasheet(PDF) 13 Page - Texas Instruments

BQ2010 Datasheet(HTML) 13 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

Datasheet Download

Link URL