Will the same chip produced by different manufactures work differently

[wars0696]

Hi,

I've got a problem with a third of my communications units not working correctly. I've narrowed the problem down to one PCB (and have eliminated all the obvious faults), the only noticeable difference between the working and none working PCB is that the IC 73M550-IP on the working boards was manufactured by Silicon Systems and the same IC on the none working board was manufactured by TDK. Can the manufacturer really be the problem?

Many thanks.

 

[Nigel Goodwin]

The manufacturer could be the problerm, but normally only if you're using the chip outside it's design limits - for example using CMOS gates as oscillators, different manufacturers produce wildly different frequency, or won't oscillate at all.

 

[Pommie]

Can you swap two of the chips over to see if the problem moves with the chip. Often when boards have different chips they are from a different assembly house and may have a completely different problem.

Mike.

 

[wars0696]

Unfortunately it's a 40 leg IC soldered directly to the PCB so can't guarantee removing both ICs with destroying one or both. And don't have any spares as yet, so reluctant to do so.

 

[power58]

When I was At AT&T we had a board with an 8253 timer. After production began some boards would not boot up right. After much traceing With a Fluke ICE we found that a pin on the Intel 8253 was pos edge trigged and the NEC 8253 was neg edge trigged, the NEC chips caused the problems , but were the same part number and had same design specs. So yep could be a problem with different vendors.

 

[Diver300]

As Nigel said, if a chip is used outside it's parameters, it may not behave like a chip from another manufacturer.

I did some repairs on a circuit that used 556 dual timers. I think the design was poor in that the power was turned on and off to the 556 while the reset line stayed high.

I forget which manufacturer's 556 worked, but one did and one didn't under those conditions.

Some CMOS logic ICs quote very different power dissipation capacitances, depending on which manufacturer they come from.

 

[Mikebits]

Hi,

I've got a problem with a third of my communications units not working correctly. I've narrowed the problem down to one PCB (and have eliminated all the obvious faults), the only noticeable difference between the working and none working PCB is that the IC 73M550-IP on the working boards was manufactured by Silicon Systems and the same IC on the none working board was manufactured by TDK. Can the manufacturer really be the problem?

Many thanks.

Is this part a UART? I think I found a data sheet for substitute part.

UART, uart, UARTs, Serial Communication, Data Communication, Twist Semiconductor :: Products

http://www.twistsemi.com/downloads/TG16C550V1.5.pdf


If there is a problem between manufacturers then I would suspect your setup and hold times are marginal. You should verify your read write timing.

 

[Leftyretro]

Well I had a lot of experiance with TTL chips in the 70s and 80s. I would find sometimes that things like temperature margins, voltage margins, etc, could vary from IC manufacture to manufactue.

Normally you should expect them to be interchangable without problems, but sometimes problems would be seen. This was probably more a function of poor circuit design where they were pushing to a near limit of some IC spec.

Lefty