FPGA power supply problem

Thread Starter


Joined Feb 25, 2021
I designed an FPGA Spartan 6 circuit that its power supply is supplied using 1117 regulators.
This circuit has two power supplies, 3.3 and 1.2 V.
The circuit worked properly for several months, but after a while the regulators and the fpga itself became hot, and the power supply increased from 1.2 volts to 2.4 V.
When the voltage regulator is connected to fpga and 3.3 V is disconnected from the circuit, the voltage is exactly 1.2 , but when the 3.3 V regulator is connected to the circuit, the voltage of the 1.2 V regulator increases to 2.4V.
Does anyone know the reason for this problem?

Deleted member 115935

Joined Dec 31, 1969
whats the current they need to provide
what heat sinking have you on them ?
what bulk capacitance do yo have ?

how do you ensure power up sequence ?

Are any of the LDO "motor botting" , how much noise do you have on the lines.