How much current for writing to data EEPROM?

Enhanced mid-range devices. PIC12F1xxx and PIC16F1xxx

How much current for writing to data EEPROM?

Postby tunelabguy » Sat Dec 13, 2014 5:20 am

I am looking for the spec on the max. current drawn during a write to data EEPROM. The reason is I need to design a power supply cap to keep the Vcc up for the time required to write to EEPROM when the power starts going down. I will get an interrupt as soon as the +12v supply drops to +11v. My PIC16F1823 will be powered from a 5-volt regulator from this falling 11v. The regulator will work down to +6v. I think I want to use a 47 uF cap on the +12v. The PIC is running at the internal 31kHz. When the interrupt hits, I can turn off all other current drains immediately. So the only remaining current drain is the PIC itself, and I want to write out 1 byte to data EEPROM before the power dies. That is 5 msec. max. The drop from +11v to +6v over 5 msec. can supply about 47 ma. That sounds like plenty for a PIC running at 31kHz, but that doesn't take into account the extra current required to do the data EEPROM write, hence my query. I did see the spec for programming the program EEPROM where it takes 5 ma. typical on Vdd during program writes, so I suspect data EEPROM writes are similar, but I did not see that spec.
User avatar
tunelabguy
Verified identity
 
Posts: 29
Joined: Sun Jul 20, 2014 9:41 pm
PIC experience: Professional 5+ years with MCHP products

Re: How much current for writing to data EEPROM?

Postby jtemples » Sat Dec 13, 2014 7:06 pm

I've never seen that specifed in any PIC data sheet. But if you look at Microchip's standalone EEPROMs (which you might assume are similar to what's in a PIC), 3 mA seems to be typical.
jtemples
Verified identity
 
Posts: 163
Joined: Sun May 25, 2014 2:23 am
Location: The 805
PIC experience: Professional 5+ years with MCHP products


Return to 14-Bit Core (enhanced)

Who is online

Users browsing this forum: No registered users and 1 guest