BQ34210-Q1 Datasheet, PDF (10/19 Pages) Texas Instruments – Automotive 1-Series Cell System-Side CEDV Fuel Gauge for Rarely Discharged Batteries

bq34210-Q1
SLUSCG1 – AUGUST 2017
www.ti.com
Feature Description (continued)
7.3.7 Gas Gauging
The bq34210-Q1 device features the Compensated End-of-Discharge Voltage (CEDV) gauging algorithm. This
algorithm uses the accumulated measured quantities for charge and discharge in addition to estimating self-
discharge of the battery. Registers including Remaining Capacity, Design Capacity, Full Charge Capacity, and
Discharge Count Register (DCR) are used in this algorithm.
7.3.8 Battery Condition Warnings
Battery status indications are stored in registers and are used by the device to take action and provide warnings.
Examples of indicator parameters are state-of-charge low detection, overtemperature-in-charge, and battery
voltage high/low.
7.3.9 Configuration Update
CONFIG UPDATE mode is used when updating the configuration data of the fuel gauge. Gauging is disabled
during this mode. This is required when a new battery is inserted.
7.3.10 End-Of-Service Determination
The bq34210-Q1 device incorporates the End-of-Service (EOS) Determination function to calculate the end of
useful service of the battery and to provide alerts based on this detection. Learning phases are used to gather
information about the present state of the battery through its cell resistance.
7.3.11 Battery Level Threshold
The Battery Level Threshold (BLT) feature indicates when the SOC of a battery pack has depleted to a certain
value stored in a register. The thresholds can be set for the charge and discharge conditions.
7.3.12 Communications
7.3.12.1 I²C Interface
The slave-only fuel gauge supports the standard I²C read, incremental read, quick read, one-byte write, and
incremental write functions. The 7-bit device address (ADDR) is the most significant 7 bits of the hex address
and is fixed as 1010101. The first 8 bits of the I²C protocol are, therefore, 0xAA or 0xAB for write or read,
respectively.
7.3.12.2 I²C Time Out
The I²C engine releases SDA and SCL if the I²C bus is held low for 2 seconds. If the fuel gauge is holding the
lines, releasing them frees them for the master to drive the lines. If an external condition is holding either of the
lines low, the I²C engine enters the low-power SLEEP mode.
7.3.12.3 I²C Command Waiting Time
To ensure proper operation at 400 kHz, a t_(BUF) ≥ 66 μs bus-free waiting time must be inserted between all
packets addressed to the fuel gauge. In addition, if the SCL clock frequency (f_SCL) is > 100 kHz, use individual 1-
byte write commands for proper data flow control.
7.3.12.4 I²C Clock Stretching
A clock stretch can occur during all modes of fuel gauge operation. In SLEEP mode, a short ≤ 100-µs clock
stretch occurs on all I²C traffic as the device must wake up to process the packet. In the other modes
(INITIALIZATION, NORMAL), a ≤ 4-ms clock stretching period may occur within packets addressed for the fuel
gauge as the I²C interface performs normal data flow control.
7.3.13 Additional Data Memory Parameter Descriptions
The calibration method requires a correction due to offset errors, using a number of samples to get a statistical
average for the golden image.
10
Submit Documentation Feedback
Product Folder Links: bq34210-Q1
Copyright © 2017, Texas Instruments Incorporated