Temperature
12
SLUUBD3D – September 2015 – Revised September 2018
Copyright © 2015–2018, Texas Instruments Incorporated
Basic Measurement System
To support large battery configurations where the battery voltage can exceed 32767 mV, the data should
be scaled as the gauge's internal data processing is done in a signed integer range (–32768 to 32767) to
ensure accurate reporting through the SMBus. The data reported is scaled based on the setting of the
SpecificationInfo()
command. The cell voltages are not scaled.
2.4
Temperature
The bq78350-R1 receives temperature information from external or internal temperature sensors in the
bq769x0 AFE. Depending on the number of series cells supported, the AFE will provide one, two, or three
external thermistor measurements. The value of temperature is reported through
Temperature()
and can
be configured in DA Configuration.
2.4.1 FET Temperature Measurement
The bq78350-R1 can be configured to report FET temperature, which can be available through
DAStatus2()
. If multiple temperature sensors are selected for FET temperature, then either the average or
highest is used based on the setting of
[FTEMP]
in
[DA Configuration]
.
The selection of temperature sensor as cell temperature protection or FET temperature protection can be
made through the
Temperature Mode
register.
2.4.2 Temperature Enable
This register enables/disables the available temperature sensor options.
Class
Subclass
Name
Format
Size in
Bytes
Min
Max
Default
Unit
Settings
Configuration
Temperature
Enable
hex
1
0x00
0xFF
0x09
—
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Low Byte
RSVD
RSVD
RSVD
RSVD
SOURCE
TS3
TS2
TS1
RSVD (Bits 7–4)
: Reserved
SOURCE (Bit 3)
: Configure the use of Internal or External temperature sensors for all AFE ports
0 = Use internal temperature sensor(s)
1 = Use external temperature sensor(s)
TS3 (Bit 2)
: Enable/disable companion AFE temperature sensor TS3, if available
0 = Disable TS3 temperature sensor
1 = Enable TS3 temperature sensor
TS2 (Bit 1)
: Enable/disable companion AFE temperature sensor TS2, if available
0 = Disable TS2 temperature sensor
1 = Enable TS2 temperature sensor
TS1 (Bit 0)
: Enable/disable companion AFE temperature sensor TS1
0 = Disable TS1 temperature sensor
1 = Enable TS1 temperature sensor
2.4.3 Temperature Mode Configuration
Each available external temperature sensor can be configured to be used for the cell temperature or FET
temperature features.