General Purpose Low Level Ignition Drive

[Dan]

Testing of the TC4427A and MC34152 (replacement for MC33152) commences this coming Tuesday (my time).

My plan is to use a decade box to place various amounts of resistive load on the output pins of the above devices, whilst maintaining fixed supply voltage. Then repeat, using the same loads, with different levels of supply voltage (5V, 12V, 14.4V, etc).

I will be measuring IC supply voltage, IC current draw, each channel's output voltage and current.

Any other thoughts on the above? is there anything else I should test to support/discredit these devices?

EDIT: I am planning to keep an eye on IC temperature but not by a measurable means. Should I be measuring the IC temperature though? maybe with a small t/c or rtd that I could mount on top of the IC under test?

NOTE: Both IC's will be the DIP8 packaged devices, purely to make my life easier in terms of testing. If either/both of these devices pass and are found to be acceptable, the SMD variant would possibly be the package used in my design/s.

[Fred]

Great to hear!

Load values you're planning to use? I'm thinking:

10, 47, 100, 330 in reverse order (lightest first)

10 will probably get it hot, but 50 might be OK, and 100 should be OK, which is what we need, so fingers crossed :-)

Are you planning to load both channels at the same time? Or test twice with one channel and then both?

(13:31:58) Fred: do you have an IR gun?
(13:32:03) Fred: if not, just touch
(13:32:06) Fred: warm = fine
(13:32:13) Fred: can't hold finger on = not

I'm using the DIP8 MC33152 to drive an LED that's fed with 12V at the moment, though it's only 17.4mA. It's working swimmingly, though.

I think 5/12/15ish are fine; no need for other voltages?

Fred.

[Dan]

Agreed, using commonly available resistor values, 330ohm, 100ohm, 47ohm and 10ohm are a good choice.

Supply values of 5V, 12V and 15V should be good enough too.

I don't own an IR gun, but I can borrow one for a few days from work, so no big deal there. I will see if we have some contact temperature measuring devices at work also though, as if I can get something that I can place on the IC under test and leave it there for the duration that that particular IC is being tested for, it would be close to ideal.

I will tabulate my findings and report back once I have the abovementioned data.

[Fred]

[TonyS]

My plan is to use a decade box to place various amounts of resistive load on the output pins of the above devices ...,

Any other thoughts on the above? is there anything else I should test to support/discredit these devices?

Hi Dan,

I don't know what the power dissipation specs for your "decade box" are, but the small ones we had used 0.25W resistors and there were quite a few boxes laying around that were damaged because of over-dissipation.

Also, what on/off timings were you planning to use? (x)ms on /(x)ms / off, continuous for (x) seconds, ...?

Thanks,
Huff

[Dan]

Decade box is rated to either 5W or 10W (I can't remember exactly) so it is more than adequate for the task at hand.

Wasn't planning on using on/off timing, just a constant high on the channel's input, observe/record behavior of the corresponding output, then repeat for the other channel and then finally repeat with both channel's on at once.

[Dan]

But if I did inject a square wave, it would be 50% duty cycle. Not sure what frequency would be best though. But I don't think potential time-shift, etc are problems we are focusing on with this testing regime. It is more the ability of the IC's under test to drive various loads and behave accordingly (hopefully).

[Fred]

On is fine, worst case is dizzy use with 80%+ duty, so 100% is good to test for IMO.

I don't think you need to do both channels one by one do you? Just one, then both?

[DaWaN]

Testing of the MC34152 ondifferent levels of supply voltage (5V, 12V, 14.4V, etc).

I do not want to be rude but....do you know the MC34152 features a undervoltage lockout at 5.8V?

[Fred]

Testing of the MC34152 ondifferent levels of supply voltage (5V, 12V, 14.4V, etc).

I do not want to be rude but....do you know the MC34152 features a undervoltage lockout at 5.8V?

We don't call that rude, here; we call it helpful! Thanks, good spotting. That makes it unsuitable for logic level duties, only ignitor duties. Still worth testing, though. That behaviour should show up pretty obviously :-)