The difference between different Lattice CPLD? Which to use?

[chicken_feet]

Hi all,

Would like to ask on the significant differences on the ispMach 4000V/B/C and ispMachZ and ispMach 4A5 series...

All I could gather from the spec is that -

isp Mach 4000 series - runs at 1.8V to 3.3V, Low static current

isp Mach Z series - runs only at 1.8V and lowest current consumption

isp Mach 4A5 - the only one that runs in 5V, highest pin to pin delay


I need to use CPLD in my system and does not critical requirement for the speed of the CPLD. Power consumption is also not an issue, so which one should I use? I have on board 5V and 3.3V power supply but all accompanying IC are based on 5V CMOS.

Is it a common practice to use a 3.3V CPLD in a 5V system? What is the max current sinking and sourcing of the CPLD i/o pin with a Vcc supply of 3.3V? Can it be use to drive a LED?

Also, if I were to use the 4A5 Series with a Vcc of 5V, the spec mention that the IO will still runs base on a Vcc of 3.3V. Does this means then it's IO output will be 3.3V when high and 0V when low? Will this be a source of problem when interfacing with other 5V CMOS ic?

Which of the series are cheaper for the same volume? I am looking at either the Mach 4000 or Mach 4A5 series. Thanks and have a good day.

chicken_feet

 

[puviarasu]

hi you r concentrating on a single manufacturer this you can get better answer from their tech support team itself. Here some would have used some series of cpld's not all as there are n number of manufacturers and devices.

 

[lucbra]

Re: The difference between different Lattice CPLD? Which to

I have some experience with Lattice CPLD's, so here is my answer:
If you have a 5V system, the only option is to use the M4A5's. This is a single voltage part, but the outputs drive only 3.3V. However this is usually no problem as most of the devices have an input tolerance below this 3.3V.
If you can use 3.3V as system power, then I can recommend the Mach4000 series. Very low cost, easy to use and robust.
On top the software is free.

Regards
L