BQ20Z80-V102 Datasheet, PDF (9/24 Pages) Texas Instruments – SBS 1.1-COMPLIANT GAS GAUGE ENABLED WITH IMPEDANCE TRACK-TM TECHNOLOGY FOR USE WITH THE bq29312A

bq20z80-V102
www.ti.com
SLUS681A – NOVEMBER 2005 – REVISED MARCH 2006
FEATURE SET (continued)
LED Display
The bq20z80 can drive 3-, 4-, or 5- segment LED display for remaining capacity indication.
LifeTime Data Logging Features
The bq20z80 offers a lifetime data logging array, where all important measurements are stored for warranty and
analysis purposes. The data monitored includes:
• Lifetime maximum temperature
• Lifetime minimum temperature
• Lifetime maximum battery cell voltage
• Lifetime minimum battery cell voltage
• Lifetime maximum battery pack voltage
• Lifetime minimum battery pack voltage
• Lifetime maximum charge current
• Lifetime maximum discharge current
• Lifetime maximum charge power
• Lifetime maximum discharge power
• Lifetime maximum average discharge current
• Lifetime maximum average discharge power
• Lifetime average temperature
Authentication
The bq20z80 supports authentication by the host using SHA-1.
Power Modes
The bq20z80 supports 3 different power modes to reduce power consumption:
• In Normal Mode, the bq20z80 performs measurements, calculations, protection decicions, data update in 1
second intervals. Between these intervals, the bq20z80 is in a reduced power stage.
• In Sleep Mode, the bq20z80 performs measurements, calculations, protection decicions, data update in
adjustable time intervals. Between these intervals, the bq20z80 is in a reduced power stage.
• In Shutdown Mode the bq20z80 is completety disabled.
CONFIGURATION
Oscillator Function
The oscillator of the bq20z80 can be set up for internal or external operation. On power up, the bq20z80
automatically attempts to start the internal oscillator. If a 100-kΩ resistor is not connected to ROSC (pin 33), then
it attempts to start the oscillator using an external 32.768-kHz crystal.
NOTE:
Install either the 100-kΩ ROSC resistor or the 12-pF, 32.768-kHz crystal. Do not
install both.
The performance of the internal oscillator depends on the tolerance of the 100-kΩ resistor between RSOC (pin
33) and VSSA (pin 34). Choose a resistor with a tolerance of ±0.1%, and 50-ppm or better temperature drift.
Place this resistor as close as possible to the bq20z80. If a 12-pF crystal is used, place it as close as possible to
the XCK1 (pin 34) and XCK2 (pin 33) pins. If not properly implemented, the PCB layout in this area can degrade
oscillator performance.
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