16V8 and other SPLD - power consumption
16V8 and other SPLD - power consumption
(OP)
Hi,
I will probably need to replace a bunch of CMOS (74HCTxx) with Lattice (or Altera) PLDs. But it seems to be a problem with current consumption. I can have devices that guzzle up to 100 mA and it does not look like the current goes down much when the clock is taken down.
And what about the Altera "turbo" thing? Is it needed to keep speed up? And what will the power consumption be if turbo is turned off - and what will the delay be like?
I really need some input here. What makes are there? What selection criteria are there? Pitfalls?
I will probably need to replace a bunch of CMOS (74HCTxx) with Lattice (or Altera) PLDs. But it seems to be a problem with current consumption. I can have devices that guzzle up to 100 mA and it does not look like the current goes down much when the clock is taken down.
And what about the Altera "turbo" thing? Is it needed to keep speed up? And what will the power consumption be if turbo is turned off - and what will the delay be like?
I really need some input here. What makes are there? What selection criteria are there? Pitfalls?





RE: 16V8 and other SPLD - power consumption
Cypress has some devices that appear to be relatively low power:
http:
Xilinx has some PLDs, with some that are relatively low power:
http
but, obviously, it depends on what total capacity you need.
some brute-force searching:
http://www
TTFN
RE: 16V8 and other SPLD - power consumption
RE: 16V8 and other SPLD - power consumption
Just a thought.
RE: 16V8 and other SPLD - power consumption
The problem is that the signals arrive randomly and there is no way of telling beforehand. I studied the Altera turbo feature a bit more and switching it off reduces current - but also speed. And I need 10 to 12 ns/gate or better. I do not need a complex device - only something like the 16V8 - but I need low power. The device is battery powered and uses less than 5 mA in its present form. Putting a 100 mA device in is not very attractive.
I was thinking that someone knew about low-power and fast PLDs, perhaps?
RE: 16V8 and other SPLD - power consumption
If the former, then it might be easier on the power to hybridize the circuitry.
TTFN
RE: 16V8 and other SPLD - power consumption
RE: 16V8 and other SPLD - power consumption
TTFN
RE: 16V8 and other SPLD - power consumption
One thing you have to take care about: most of these devices (xilinx and other brands as well) do not readily interface with 5-volt logic. Some of them require series resistors, some don't, and even if some are tolerant to 5-volts, they still have a DC path to the 3.3V rail, making it harder to get 5 volts of output even with a pullup resistor.
RE: 16V8 and other SPLD - power consumption
They claim a max of 35 mA standby current
TTFN
RE: 16V8 and other SPLD - power consumption
The running current is due to the charging & discharging
of the capacitances -- this is proportional with frequency
and depends on process and geometry
<nbucska@pcperipherals DOT com> subj: eng-tips
read FAQ240-1032
RE: 16V8 and other SPLD - power consumption
The datasheet reports ICC "Standby Current" at 35 mA. Standby, by definition, is a static condition.
TTFN