kinjalgp said:
ADG411 is a precision analog switch with on resistance below 35 Ohms which is comparable to relay's contact resistance of 10-15 Ohms.
Switching speed of 411 is 175nS and relay comes no where near it (20-30mS).
I have seen IC programmers which use ADG411 for Vpp and Vcc switching.
Well, I don't want to go overboard promoting relays, because I admit that other options may work for our OP, and I don't want to get into a pissing contest with kinjalgp, but I hate to see questionable information go unchallenged:
1. Most electromechanical relays have contact resistance in the 100 milliohm range. The one I suggested has 100 milliohms MAX contact resistance. I would like to see a spec sheet on a relay with 10 ohms contact resistance.
2. 35 ohms is probably fine for Vpp (programming voltage on an EPROM), but if I were building a general purpose IC tester, I wouldn't want that much resistance in series with either power pin - certainly not in the ground lead.
3. Most small relays switch much faster than 20ms. The one I suggested,
**broken link removed**, has 5ms maximum switcing time plus 5ms max bounce time. Typical times are much faster. Switching time really isn't important for this application anyway. The relays apply power to the appropriate pins, and they stay on until the test is over. The time to insert and remove the IC is going to dominate, unless the tester is in an automated setup.
Ron