GS8522 adder circuit mysterious short circuit

PunkGibson

GS8522 adder circuit mysterious short circuit [Copy link]

When using GS8522 to test the circuit, it was found that LED2 was on after power-on, but LED1 was off.

The DC regulated power supply detected a short circuit, the positive input dropped from 5V to 0.08V, the -5V LED2 was on, and the +5V LED1 was off. At this time, the chip was hot when touched, indicating a short circuit. After that, I tried to solder only the first-level op amp and surrounding resistors, and the phenomenon was the same. When the circuit simulation used OPA2140 instead of GS8522, the simulation test results were normal.

What I don't understand is that the function of this circuit is an adder. The first stage is composed of two voltage followers (using the chip GS8522), and the second stage is a common adder (also using GS8522). For the first-stage voltage follower, GS8522 should be used instead of OPA2140. However, actual testing found that when only the first-stage voltage follower was soldered, the above short circuit phenomenon still occurred. After inspection, there was no problem with the soldering, but it seemed that the schematic diagram and PCB were also fine. I would like to ask what the possible reason could be?

呜呼哀哉

This OPA2140 is a dual op amp, the power pins are 8 positive and 4 negative, you got the power supply wrong. Is this expensive? Is it several dozen dollars?

beyond_笑谈

OPA2140 datasheet and pin diagram are as follows: pin8: +, pin 4: - (dual power supply) or 0V (single power supply)