If the 741's output is connected to PSOC pin, and the 741 is working
off power supplies +/- 5 to +/- 12 or +/-15, th en good chance PSOC has
been damaged. The PSOC can only handle ~ its Vdd + .5 to Vss - .5
What board are you using ?
I use the CY8CKIT-030 PSoC3 DEVELOPMENT Kit
What can I do? Contact to after-sale service. Thank you very much
You can do a simple test program on the pin to see if its still
working, if PSOC can still run a program.
Or use a subcontractor to replace PSOC on board. If you search
youtube.com there are several videos where people have successfully
soldered SMD with toaster ovens / heat guns.
Or contact local FAE / Cypress Regional sales manager to see if they
have any contacts for board repair.
Note you would have to establish what other components might have
been damaged, like regulators, etc, by troubleshooting schematic to
see if other power domains OK.
ps:I use the GPIO as a output pin and attach it to 741.I use a independent power to supply electricity for 741，but I forget to common ground PSoC's GND and power‘s GND. It can be a problem to damage the board？
Was the 741 output pin attached to the PSOC ? Or the PSOC pin
attached to an input of the 741 thru a R ?
A schematic of connections would help.
The PSOC pin attached to an input of the 741 .
Without a schematic of connections hard to help you.
But consider taking a DSO scope, and look at startup transients
on pin from 741 connected to PSOC. Set DSO to one shot trigger,
trigger level close to ground, and look at the input as well as the
741 power rails. What you are looking for is a transient at 741 input
that would violate PSOC input levels.
Not all 741's are same internal design, in terms of CMOS or Bipolar,
and internal protection circuits. Additionally parasitic structures.