• ADC
PACK
= [ADC
PACK
(reading n) + … + ADC
PACK
(reading 1)]/n
7. Calculate gain value:
16
2
PACK
PACK
V
PACK Gain
ADC
=
´
8. Write the new
PACK Gain
value to data flash.
9. Recheck voltage readings and if they are not accurate, repeat Steps 4 through 6.
10. Send 0x002D to
MACSubcmd()
to clear the
[CAL_EN]
flag if all calibration is complete.
11.4 Current Calibration
11.4.1 CC Offset Calibration
Note
Because of hardware improvements in this device,
CC Offset
Calibration is not necessary. Only run
the
CC Offset
Calibration procedure if offset current is observed.
1. Apply a known current of 0 mA, and ensure no current is flowing through the sense resistor connected
between the SRP and SRN pins.
2. If
ManufacturerStatus()[CAL_EN]
= 0, send 0x002D to
MACSubcmd()
to enable the [CAL_EN] flag.
3. Send 0xF082 to
MACSubcmd()
to enable raw cell voltage output on
MACData()
.
4. Poll
MACData()
until ZZ increments by 2 before reading data.
5. Obtain the ADC conversion readings of current from
MACData()
:
• ADC
CC
= AAaa of
MACData()
Is ADC
CC
< 0x8000? If yes, use ADC
CC
; otherwise, ADC
CC
= –(0xFFFF – AAaa + 0x0001).
6. Average several readings for higher accuracy. Poll
MACData()
until ZZ increments to indicate that updated
values are available:
• ADC
CC
= [ADC
CC
(reading n) + … + ADC
CC
(reading 1)]/n
7. Read
Coulomb Counter Offset Samples
from data flash.
Calibration
SLUUCO0 – APRIL 2022
BQ28Z610-R2
61
Copyright © 2022 Texas Instruments Incorporated
