Need Help Identifying '45A 9081' Marked TSSOP EEPROM

[Mechatrommer]

probably TSSOP, cant measure too small and congested. its serial EEPROM thats affirmative from the service manual (named only as IC7 ) google returns unexpected results.
btw: its my canon flash 550EX unit thats giving faulty flash power output (full discharge at minimum 1/128 power setting). there are many areas to suspect, one of it is, faulty or erased EEPROM content, is it possible after about 5 years of service? thanks.

[amyk]

I've seen this part number (9081) before somewhere... although I can't remember exactly where

Part number suggests Rohm (they have a BR9080 but it's a different interface) - the AK6440BH and the like have the same "SCI bus" interface (something like SPI but a Japanese variant) so maybe you could figure out the rest from there. Put a logic analyser on the signals and see what you get.

[mikeselectricstuff]

Pinout looks like fairly standard 93xx SPI style - probably worth trying to read as one of those. 

[fluxcapacitor]

My guess its a  ASAHI KASEI AK93C45A

[amyk]

My guess its a  ASAHI KASEI AK93C45A

Doesn't have a RESET pin.

If the OP is looking at the same schematic as I am, this particular EEPROM has a pinout like this:

Code: [Select]

 *---------+
1|/CS   VCC|8
2|/SK    NC|7
3|DI  RESET|6
4|DO    GND|5
 +---------+

[fluxcapacitor]

My guess its a  ASAHI KASEI AK93C45A

Doesn't have a RESET pin.

If the OP is looking at the same schematic as I am, this particular EEPROM has a pinout like this:

Code: [Select]

 *---------+
1|/CS   VCC|8
2|/SK    NC|7
3|DI  RESET|6
4|DO    GND|5
 +---------+

But pin 6 and 7 aren`t connected ? I couldn`t find the schematic ,the only one i could find was for the 580EX ,i assumed wrongly that it would have a similar layout and eprom .I did look at the pinouts on plenty of datasheets but on all of them pins 5-8 were different. Any chance you can upload your schematic .
My mistake amyk ,i didnt read your answer correctly .I found the 550EX schematic though.

[amyk]

Oops... looks like we both made the same mistake - I assumed the 580EX would have the same EEPROM. But RESET pin is tied to ground so not used anyway.

In that case, I'd agree with 93Cxx.