Problem with MAX038 Function Generator IC

Status
Not open for further replies.

Thread Starter

ericfellip

Joined May 10, 2013
10
Well, there is one detail left behind about my power supply, and I believe you will scream to me I shouldn't have done it (and I know I shouldn't :x ), but both my regulators are running without heatsinks, because it doesn't sell in electronics stores here in Brazil and I don't have enough money to buy a piece of aluminum and have someone cut it for me. Could the heatsinks be causing this instability?

I was prototyping a circuit entirely different from the MAX038 one, it was a audio power amplifier with the TDA2822M chip, and I put it to run with 4.5V on the +V rail (not using the -V one), and after I plug in the +V cable to the +V pin of the chip, the voltage dropped to about 3.2V. After seeing this I definitely believe now the problem is with my power supply, but I can't seem to get it (I'm having a hard time believing it can't run properly because of the heatsinks and the adjustment pin resistor, and I don't believe also that these circuits are pulling more than 1A of current, which would wreak havoc on my transformer).
 

Lestraveled

Joined May 19, 2014
1,946
The only time you NEED a heat sink is if the regulator runs hot, otherwise, a heat sink does not affect stability.
You can use almost anything made of metal as a heat sink.
 

Thread Starter

ericfellip

Joined May 10, 2013
10
Well, I went to school today and used the power supply we have on the labs, which can deliver pretty much any current the chip could possibly demand. What was happening was that the MAX038 is pulling 1,41A of current, almost 20 times what the datasheet said it would (about 80mA). It went on for about 10 seconds until that current was too high and it literally fried.

After that, my teacher reviewed the schematic I made based on the datasheet and according to him I wired everything correctly (I was starting to think I would have to quit Electronics...), so I left the other MAX038 chip I have with him so he can mess around with it a little.

I won't be messing with it anymore, so thanks for all of you who extended a hand to help a brother in need, really appreciate it! :)

Eric.
 

MrChips

Joined Oct 2, 2009
21,648
When I have some time I will try to duplicate your circuit and breadboard layout in order to figure out what went wrong.
 
Status
Not open for further replies.
Top