16
1
2
1
2
{[
]
} /
2
CELL
CELL
CELL
CELL
V
V
Cell Gain
N
ADC
ADC
=
+
´
where N = number of cells.
8. Write the new
Cell Gain
value to data flash.
9. Recheck the voltage reading and if it is not accurate, repeat Steps 5 and 6.
10. Send 0x002D to
MACSubcmd()
to clear the
[CAL_EN]
flag if all calibration is complete.
11.2 VC2 (BAT) Voltage Calibration
VC
VSS
V
VC
2
2
This device does not have a BAT terminal and therefore the VC2 input is the BAT terminal:
1. Apply known voltages in mV to the voltage input:
• V
BAT
between VC2 terminal and VSS terminal
2. If
ManufacturerStatus()[CAL_EN]
= 0, send 0x002D to
MACSubcmd()
to enable the
[CAL_EN]
flag.
3. Send 0xF081 or 0xF082 to
MACSubcmd()
to enable raw cell voltage output on
MACData()
.
4. Poll
MACData()
until the 8-bit counter value increments by 2 before reading data.
5. Read ADC conversion readings of cell stack voltage from
MACData()
:
• ADC
BAT
= LLll of
MACData()
6. Average several readings for higher accuracy. Poll
MACData()
until ZZ increments to indicate that updated
values are available:
• ADC
BAT
= [ADC
BAT
(reading n) + … + ADC
BAT
(reading 1)]/n
7. Calculate gain value:
16
2
BAT
BAT
V
BAT Gain
ADC
=
´
8. Write the new
BAT Gain
value to data flash.
9. Recheck the 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.
11.3 PACK Voltage Calibration
VSS
PACK
V
PACK
1. Apply known voltages in mV to the voltage input:
• V
PACK
between PACK terminal and VSS terminal
2. If
ManufacturerStatus()[CAL_EN]
= 0, send 0x002D to
MACSubcmd()
to enable the
[CAL_EN]
flag.
3. Send 0xF081 or 0xF082 to
MACSubcmd()
to enable raw cell voltage output on
MACData()
.
4. Poll
MACData()
until the 8-bit counter value increments by 2 before reading data.
5. Read ADC conversion readings of pack voltage from
MACData()
:
• ADC
PACK
= KKkk of
MACData()
6. Average several readings for higher accuracy. Poll
MACData()
until ZZ increments to indicate that updated
values are available:
Calibration
60
BQ28Z610-R2
Copyright © 2022 Texas Instruments Incorporated