BQ26501_16 Datasheet, PDF (23/33 Pages) Texas Instruments – HANDHELD APPLICATIONS

Not Recommended For New Designs
bq26501
ą
SLUS586B − OCTOBER 2003 − REVISED MARCH 2004
APPLICATION INFORMATION
Hibernate Mode
The device enters hibernate mode when V_CC drops below V_(POR) and there is a voltage source connected to
the RBI pin. V_CC must be raised above V_(POR) in order to exit the hibernate mode. This mode retains RAM
integrity and allows retention of remaining capacity, learned LMD, and the CI flag.
PROGRAMMING THE EEPROM
The bq26501 has 10 bytes of EEPROM that are used for firmware control and application data (see the Register
Descriptions section for more information). Programming the EEPROM through the HDQ pin should take place
during pack manufacturing, as a 21-V pulse is needed on the GPIO pin. The programming mode must be
enabled prior to writing any values to the EEPROM locations. The programming mode is enabled by writing to
the EE_EN register (address 0x6E) with data 0xDD. Once the programming mode is enabled, the desired data
can be written to the appropriate address. Figure 6 shows the method for programming all locations.
Host enables EEPROM programming
mode / write data 0xDD to address 0x6E
Host writes data addresses
0x76 to 0x7F
Host reads data
address to be programmed
V(PROG) pulse applied to
GPIO pin for t(PROG)
Host increments
address and reads
No
Programmed
0x7F?
Yes
Write data 0x00 to address 0x6E
Figure 6. EEPROM Programming Flow Chart
It is not required that addresses 0x76 − 0x7F be programmed at the same time or in any particular order. The
programming method illustrated in Figure 6 can be used to program any of the bytes as long as the sequence
of enable, write, read, apply programming pulse, and disable is followed.
www.ti.com
23