BQ40Z50-R2 Datasheet, PDF (24/51 Pages) Texas Instruments – 1-Series, 2-Series, 3-Series, and 4-Series Li-Ion Battery Pack Manager

bq40z50-R2
SLUSCS4 – JUNE 2017
Feature Description (continued)
• Second Level Protector Permanent Failure
• Instruction Flash Checksum Permanent Failure
• Open Cell Connection Permanent Failure
• Data Flash Permanent Failure
• Open Thermistor Permanent Failure
www.ti.com
8.3.3 Charge Control Features
The bq40z50-R2 charge control features include:
• Supports JEITA temperature ranges. Reports charging voltage and charging current according to the active
temperature range
• Handles more complex charging profiles. Allows for splitting the standard temperature range into two sub-
ranges and allows for varying the charging current according to the cell voltage
• Reports the appropriate charging current needed for constant current charging and the appropriate charging
voltage needed for constant voltage charging to a smart charger using SMBus broadcasts
• Reduces the charge difference of the battery cells in a fully charged state of the battery pack gradually using
a voltage-based cell balancing algorithm during charging. A voltage threshold can be set up for cell balancing
to be active. This prevents fully charged cells from overcharging and causing excessive degradation and also
increases the usable pack energy by preventing premature charge termination.
• Supports pre-charging/zero-volt charging
• Supports charge inhibit and charge suspend if battery pack temperature is out of temperature range
• Reports charging fault and also indicates charge status via charge and discharge alarms
8.3.4 Gas Gauging
The bq40z50-R2 uses the Impedance Track algorithm to measure and calculate the available capacity in battery
cells. The bq40z50-R2 accumulates a measure of charge and discharge currents and compensates the charge
current measurement for the temperature and state-of-charge of the battery. The bq40z50-R2 estimates self-
discharge of the battery and also adjusts the self-discharge estimation based on temperature. The device also
has TURBO Mode 2.0 support, which enables the bq40z50-R2 to provide the necessary data for the MCU to
determine what level of peak power consumption can be applied without causing a system reset or transient
battery voltage level spike to trigger termination flags. See the bq40z50-R2 Technical Reference Manual
(SLUUBK0) for further details.
8.3.5 Configuration
8.3.5.1 Oscillator Function
The bq40z50-R2 fully integrates the system oscillators and does not require any external components to support
this feature.
8.3.5.2 System Present Operation
The bq40z50-R2 checks the PRES pin periodically (1 s). If PRES input is pulled to ground by the external
system, the bq40z50-R2 detects this as system present.
8.3.5.3 Emergency Shutdown
For battery maintenance, the emergency shutdown feature enables a push button action connecting the
SHUTDN pin to shut down an embedded battery pack system before removing the battery. A high-to-low
transition of the SHUTDN pin signals the bq40z50-R2 to turn off the CHG and DSG FETs, disconnecting the
power from the system to safely remove the battery pack. The CHG and DSG FETs can be turned on again by
another high-to-low transition detected by the SHUTDN pin or when a data flash configurable timeout is reached.
8.3.5.4 1-Series, 2-Series, 3-Series, or 4-Series Cell Configuration
In a 1-series cell configuration, VC4 is shorted to VC, VC2, and VC1. In a 2-series cell configuration, VC4 is
shorted to VC3 and VC2. In a 3-series cell configuration, VC4 is shorted to VC3.
24
Submit Documentation Feedback
Product Folder Links: bq40z50-R2
Copyright © 2017, Texas Instruments Incorporated