current limiter chip

Sep 02, 2022 Last reply: 3 years ago 32 Replies

For that, a plain old 78L05 regulator will conduct, but limit at about 200 mA. That's 'a bit above'; in SOT89 package, TS78L05ACY limits at 100 mA, nominal.

I think you're right about PWM in the BCR430 part; the datasheet resistor description makes it clearly NOT a series sense resistor for the current. I saw the pass transistor, resistor programming, and error amplifier, and drew my conclusion too soon.

The data sheet is pitiful. As is common these days.

Ideally 5 volts in and out.

We could make a limiter with a shunt resistor, an opamp, and a p-fet, and some passives; it wouldn't thermal limit so we'd have to work around that. We prefer something with fewer parts.

We do have a digital solution for this case, but I'd generally like to find a current limiter part.

lørdag den 3. september 2022 kl. 23.51.15 UTC+2 skrev snipped-for-privacy@highlandsniptechnology.com:

USB power switch like RT9728A ?

You might try Torex for the app.

eg XC6193 is a pretty fancy rail switch/controller.

XC6299/6212 are controllable LDOs with enable, inrush and thermal limits, in smaller sot23-6 type bodies.

RL

Looks nice, 32 cents by the reel, probably 2nd sourced, but doesn't seem to be available.

søndag den 4. september 2022 kl. 19.33.48 UTC+2 skrev snipped-for-privacy@highlandsniptechnology.com:

maybe one of these then?

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There is a TI part with the same pinout and similar specs. Three sources maybe.

Thanks for the suggestions.

Diodes AP22652

Richtek RT9728A, RT9722

TI TPS25221

ON NCP380

seem to be basically identical current limiter chips. This family has fixed and adjustable current limit parts, and both continuous and on/off versions.

Microchip Mic2091 and MP5036 and MIC20x9 look close.

tirsdag den 6. september 2022 kl. 17.37.58 UTC+2 skrev snipped-for-privacy@highlandsniptechnology.com:

here's a few more

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Cool.

Most of these parts bottom out at about 400 mA on their graphs, but they might limit at little lower in real life. I'd prefer maybe 200 mA, but it needn't be a precise limit, so we could test some and see if they look OK.

Check pin compatibility . . .

RL

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