Datasheet

EEPROM Write Sequence
bq77PL900
SLUS844B – JUNE 2008 – REVISED JANUARY 2009 ...................................................................................................................................................... www.ti.com
The bq77PL900 has integrated configuration EEPROM for OV, UV, OCD, and SCD thresholds and delays. The
appropriate configuration data is programmed to the configuration registers, and then 0xe2 is sent to the
EEPROM register to enable the programming supply voltage. By driving the EEPROM pin (set high and then
low), the data is written to the EEPROM.
When supplying BAT, care should be taken not to exceed VCn – VC(n + 1), (n = 1 to 10) > 5 V. If BAT and VC1
are connected onboard, it is recommended that all cell-balance FETs be ON where each input voltage is divided
with the internal cell-balance ON resistance.
The recommended voltage at BAT or PACK for EEPROM writing is 20 V. When supplying VBAT, care is needed
to ensure VBAT does not exceed the VCn – VC(n + 1), (n = 1 to 10) absolute maximum voltage. If BAT and VC1
are connected onboard, supplying 7.5 V is recommended to activate the bq77PL900 and turn ON all cell-balance
FETs.
Then increase the power supply up to 20 V. By this method, each input voltage is divided with the internal
cell-balance ON resistance.
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