Interface Ultra Violet EPROM

[king]

I want to interface an UV EPROM but in order to program it i have to give it negative pulses of -48V
(Vlow = -48 and Vhigh= 0V) and -40V (Vlow = -40 and Vhigh= 0V) ,so can anybody give me the idea that how to provide these negative pulses to EPROM in order to program it. I have also attached the datasheet of the IC please take a look and suggest me the idea to interface it.

Regards

King

[oldvan]

I'd lean toward EEPROM, but if I HAD to use EPROM, I'd buy a ready-made EPROM programmer.

Failing that, I'd use a -48V supply, a PIC to control the programming, and an opto isolator to switch the -48V on and off.

[king]

Do You have any schematic to switch 'ON' and 'OFF' -48V with the logic voltage of 5v and 0v.

[oldvan]

As I implied earlier, An opto isolator can remove all the hassles for switching -48V with logic output. 

I don't have a schematic at hand, but the bit of circuit at hand is ultra-simple.

Logic levels control the LED in the opto.  Don't forget a current limiting resistor.
The opto's output switches the -48V.
If more current is needed than the opto can supply, wrap a FET around its output.

[pickit2]

Why not use a more modern eprom, I last used MM1702 in about 1980-82
but if you want to use older eproms there is loads of info on the internet.
this is one for 2708, and details for power inverter.
http://www.6502.org/users/dallas/SYM/SYM%20Projects/2708%20EPROM%20Burner/Description.htm

Thinking on this why no use a GAL or PAL device

[king]

Actually these type of EPROM's are used in our Machines and electronic card is taking data from these EPROMs and we dont have any programmer to program it so we have to buy new card when the data or EPROM becomes faulty so thats why there is an urgent need of the Programmer and more help on this project will be highly appreciated.


And as far as 2702 concerned then it think the supply voltages of 1702 and 2702 are different because mm1702 requires as whole (+5v, -12v,-9V,-48V,-40V and +12v)many power supplies to program it and i am facing problem in negative voltages can anybody help me in solving these power supply votages issue because i need the power supply with the same Ground.

Regads

King

[pickit2]

ok. I understand what you want to do.
I would find a way to read a 1702 and program a 24-pin 2816/28C16, EEPROM
and build a mini plug to mount it in your pcb see link.

http://www.shout.net/~rieslabs/HomebrewSyntorPLPromAdapter.htm

NOTE: you only need A0 to A7 for 256x8 data, the rest can be tied low.

http://www.burnyourbonus.info/sci.electronics.design/thread1962.html

[oldvan]

For a negative supply:  Make a power supply, regulated 48V output.  Use an appropriate transformer.  
Connect the + terminal to GND and you have a -48V supply.  Regulate from there down to 40V.
Repeat the pattern for -12V, -9V.

I'd buy a ready-made EEPROM programmer.  Probably cheaper than total parts cost to build one.

Hint:  There's an important button that can easily increase one of these numbers...

It lets people who try to help you know that their effort is appreciated.

[king]

Hi!

This is hard to make own programmer so can anybody tell me from where i can buy the ready made programmer to program MM1702A EPROM's.

[pickit2]

I still think my post at #6 is still a valid option, you can read the MM1702A with just a power supply and a few switches, (or get your printer port to read it), then have a eeprom programmed with the code.

The MM1702A is an obsolete device, and as such none of the newer programmers have it in the list of devices.
Data Sheet http://www.jmargolin.com/patents/1702a.pdf

see here but 1702 is not there.
http://www.ebay.co.uk/itm/G540-USB-universal-programmer-EPROM-FLASH-MCU-GAL-PIC-/280627978750?pt=LH_DefaultDomain_0&hash=item4156bb21fe

[king]

Pickit2! your idea is really nice to use EEPROM other than 1702A after getting data, but stilll there is one problem that the EEPROM which i have to use in place of 1702A should have the same reading procedure as 1702A has i-e ( To read Data from 1702A EPROM)
1) apply constant voltages on VGG, Vcc , Vbb and CS pins
2) then give the address in TTL logic and receive data of corresponding address

but latest EEPROM use clock pulse either on /OE pin or /CS for the transition of data.
So how do we solve this problem

Posted on: July 27, 2011, 09:37:05 21:37 - Automerged
Can anybody has the idea to switch negative voltage(-48V) by TTL input. If Yes then please share it

[pickit2]

you need to look a static eeprom not the 8pin serial type.
this can be used on original board with a little work
http://pdf1.alldatasheet.com/datasheet-pdf/view/124195/MAXWELL/28C256T.html