ULN2003 - Confirming Vce(sat) and Ii over Temperature

languer

Other Parts Discussed in Thread: ULN2003A, TPL7407L, SN65472-EP, SN75477, SN75472, DRV8803

We have an application where we will use the ULN2003A to drive a fairly resistive output from +28V to GND. The input voltage will be 0 to +3.3V.

I want to confirm that I am correctly reading the datasheet and that for a load (sink) current of approximately 20mA (50mA max), each output will have a maximum Vce(sat) of approximately +1.2V over the operating temperature range (-40C to +105C); with +1V being a typical value (over temp).

I also want to confirm that each input will have a maximum input current of approximately 1.2mA over the operating temperature range (-40C to +105C); with 700uA being a typical value (over temp).

Thanks in advanced.

over 10 years ago

0 Ron Michallick over 10 years ago

TI__Guru**** 165316 points

Langue,

28V resistive load is good. Connect 28V supply to COM pin.

Max VCE will be less than 1.2V, typical around 0.9V

Input current is correct.

0 languer over 10 years ago in reply to Ron Michallick

Prodigy 100 points

Thank you Ronald. I have one more question. Would the TPL7407L be a good alternate to the ULN2003A? It seems to be pin-for-pin. Saturation voltage seems lower (at about 0.320V), and input current seems also lower (at about 10uA); output leakage current also seems lower. Any thoughts on the TPl7407L?

0 Ron Michallick over 10 years ago in reply to languer

TI__Guru**** 165316 points

Langue,

The TPL7407 will dissipate less power and draw less current on the input.

This performance improvement comes at a small cost increase.

Either device will work with the inputs and load specified.

0 languer over 10 years ago in reply to Ron Michallick

Prodigy 100 points

Ronald,
I need to ask you another question. The application we have requires a lower "ground" voltage than what is offered by the ULN2003A (0.9 Vce_sat). The TPL7407L seems to satisfy this (0.3 Vol). But on our system the output (and COM) voltage could increase from the nominal +28V to +32V (which the TPL7407L device seems to be able to handle), and could also see a surge of +48V for 100ms (which I can't tell if theTPL7407L can handle). Do you know what the surge capability of the TPL7407L is (will it tolerate the +48V for 100ms)? Do you know of other low-side drivers which have similar input and output characteristics to the TPL7407L, but with higher output voltage capability (something like 50-60V); these could be in different form factor and/or offer other channel capacity?

Again, thanks in advanced for your help.

0 Ron Michallick over 10 years ago in reply to languer

TI__Guru**** 165316 points

Langue,

48V for 100mS will be risky for TPL7407L. There is not much margin above the absolute maximum in the data sheet.

0 Ron Michallick over 10 years ago in reply to Ron Michallick

TI__Guru**** 165316 points

Langue,

We have devices in power logic that have NMOS outputs and high voltage.

www.ti.com/.../parametricsearch.tsp;familyId=356&uiTemplateId=NODE_STRY_PGE_T#p267max=50;50

Copy and paste the link into your browser. e2e doesn't work well with link with a semi colon in it.

0 languer over 10 years ago in reply to Ron Michallick

Prodigy 100 points

I looked at what is available and found the following are probably best candidates: SN65472-EP, SN75472, and SN75477. I gather the 472 and 477 only come in commercial temperature versions. Would you say the SN65472-EP then the most likely candidate?

Following is a summary of our requirements:
Package: SMT
Temperature: -40C to +85C
Breakdown/Surge Capability: >= +50V (comes from +38V/1sec and +47V/100msec)
Output working Voltage: >= +40V
Output Sink Current: >= 50mA
Vol (or Vce_sat): <= +0.5V

Again, thanks for your help.

0 Ron Michallick over 10 years ago in reply to languer

TI__Guru**** 165316 points

Langue,

The SN65472-EP will surely do the job. It has plenty of drive and temperature range. High ICC and low channel count are the only down sides I see.

0 languer over 10 years ago in reply to Ron Michallick

Prodigy 100 points

Ronald, thanks for your reply. I have another question (hopefully the last).

We have another group which have started the process to replace existing driver (one A2557KLB) with a DRV8803. It would seem this should work good (4-channels, low "ground" voltage, high surge voltage and working voltage, industrial temp). We will further review this part, but it looks like upon initial look this may be our initial candidate, with the SN65472-EP a possible alternate (in case the DRV8803 does not pan out). Any issues you may see with this approach?

0 Ron Michallick over 10 years ago in reply to languer

TI__Guru**** 165316 points

Langue,

This question deserves it's own forum post.
Please start a new thread with DRV8803 and SN65472-EP in the title.

0 languer over 10 years ago in reply to Ron Michallick

Prodigy 100 points

Will do. Thanks again.

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ULN2003 - Confirming Vce(sat) and Ii over Temperature