Order Number LMT, LMT, LMT, LM78M05CT, LM78M12CT or LM78M15CT . be kept below +˚C in order to meet data sheet specifica-. LM78M05CT – Fixed Linear Voltage Regulator, , 3-Terminal, Positive, 10V. Add to compare. Image is for Technical Datasheet: LM78M05CT Datasheet. LM78M05CT datasheet, LM78M05CT pdf, LM78M05CT data sheet, datasheet, data sheet, pdf, Fairchild Semiconductor, 3-Terminal A Positive Voltage.

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However, I usually put a blocking Schottky diode in series with the output. Jul 9 ’17 at The has an emitter follower on the datashret stage, so you have probably let the smoke out. The programming failed, and the target device has a “electronic” smell not present before. For example, your ICSP setup has a ground to earth through the computer if it’s a desktop or many notebook computers.

Desoldered the regulator, all pin combinations with polarity measure within tolerance of a new one and it doesn’t smell. Review of my first ever PCB design for a watering control robot. Also the relay smells funny. At this stage I think my move would be to replace thecheck any diodes for short circuits, power the board from a current-limited PSU and try again measuring the current draw and all supply voltages first!

LM78M05CT Datasheet PDF

Spehro Pefhany k 4 When I next plugged in the DC cord I got a spark from the ground terminal and there is a black residue from it on the solder mask of the DC plug and immediately unplugged the DC cord. But those protections can’t save the chip if it’s abused by putting 10V on the output with input grounded or 50V on the input.


It seems rather unlikely to me that this is the cause. They’re all pretty similar. Post as a guest Name. Jul 10 ’17 at 7: Is it possible the Fairchild LM has a different realisation as the linked data sheet mentions no such shunt diode nor any break down voltages? So my questions are: Home Questions Tags Users Unanswered.

I’ll have to see how if that affects the rest of my circuit. Hence I assumed it wasn’t necessary with their implementation. Also they mention short circuit protection.

The output voltage has to be greater than the reverse breakdown of the B-E junctions in the regulator to cause damage, and 5V is not. For ICSP, you can add the diode but realize your programmer will have to power whatever is on the back side, or you can select the target’s vdd on some programmers.

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For now I think I’ll jurryrig a shunt lm78m05cg on the pins as the board is already made.

LM78M05CT Datasheet(PDF) – National Semiconductor (TI)

By clicking “Post Your Answer”, you acknowledge that you have read our updated terms of serviceprivacy policy and cookie policyand that your continued use of the website is subject to these policies. There also has to be significant current flowing back both conditions are necessary for damage to occur.

I’ve seen some versions of the regulator data sheets where the application notes recommend a diode from Vout to Vin in order to protect the device from burning out if the output voltage goes higher than the input.

I’m not sure how you damaged your target. Email Required, but never shown. Further I measure in situ only R or so between the Vout and GND pins on the regulator both ways which is much less than what I would have expected.

LM78M05CT Datasheet

Bad news – You probably need the diode. That can cause issues if your circuit also has a ground to earth somewhere, and very serious issues if the two are not nominally at the same potential. Is my regulator shot?

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