BQ20Z90-V110 Datasheet, PDF (8/25 Pages) Texas Instruments – SBS 1.1-COMPLIANT GAS GAUGE ENABLED WITH IMPEDANCE TRACK TECHNOLOGY FOR USE WITH THE bq29330

bq20z90-V110
SLUS743 – NOVEMBER 2006
FEATURE SET
www.ti.com
Primary (1st Level) Safety Features
The bq20z90-V110 supports a wide range of battery and system protection features that can easily be
configured. The primary safety features include:
• Battery cell over/under voltage protection
• Battery pack over/under voltage protection
• 2 independent charge overcurrent protection
• 3 independent discharge overcurrent protection
• Short circuit protection
• Over temperature protection
• AFE Watchdog
• Host Watchdog
Secondary (2nd Level) Safety Features
The secondary safety features of the bq20z90-V110 can be used to indicate more serious faults via the SAFE
(pin 10) pin. This pin can be used to blow an in-line fuse to permanently disable the battery pack from charging
or discharging. The secondary safety features include:
• Safety over voltage
• Battery cell imbalance
• 2nd level protection IC input
• Safety over current
• Safety over temperature
• Open thermistor
• Charge FET and Zero-Volt Charge FET fault
• Discharge FET fault
• Fuse blow failure detection
• AFE Communication error
• AFE Verification error
• Internal flash data error
Charge Control Features
The bq20z90-V110 charge control features include:
• Report 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.
• Determine the chemical state of charge of each battery cell using Impedance Track™. Using cell balancing
algorithm, gradually decrease the differences in the cells' state of charge in a fully charged state. This
prevents high cells from overcharging, causing excessive degradation and also increases the usable pack
energy by preventing early charge termination.
• Support Pre-charging/Zero-volt charging
• Support Fast charging
• Support Pulse charging
• Support Charge Inhibit and Charge Suspend modes
• Report charging faults and also indicate charging status via charge and discharge alarms.
Gas Gauging
The bq20z90-V110 uses the Impedance Track™ Technology to measure and calculate the available charge in
battery cells. The achievable accuracy is better than 1% error over the lifetime of the battery and there is no full
charge-discharge learning cycle required.
8
Submit Documentation Feedback