Other Parts Discussed in Thread: LMZM23601
Following is a supply circuit for an Interface Board.
Input: 24 Volt DC
Output: 3.3Volt
Minimum Iout : 90 ma
Maximum Iout : 1000 ma
I connected the board to the bench supply set for 13 volts. The current showed 44ma. Output measured 3.3volt.
Connected to 24 volt supply and output measured 3.3 Volt.
The board has the following interfaces:
Typical (ma) | Max (ma) | |
STM32F765ZG | 95 | 258 |
LAN | 50 | 70 |
USB | 35 | 40 |
ESP 32 Wifi | 300 | 500 |
Programmed the board STM32F7 and powered the board. It worked fine.
Connected USB connector to PC. It was recognized.
Disconnected the power.
Made some changes to code. Reconnected the power and tried to program it and no connection.
Checked the supply voltage. No supply voltage and all power components are burning to touch.
At this stage, only USB and STM32F7 is active.
Connected the bench supply back, and it looks like Vin and Vout of U2 is shorted.
Checked with Ohm meter between Vin and Vout of U2 and it reads zero ohms.
Connected the supply passed Q1 (bypassing Q1) the same.
Connected the supply passed L2 (bypassing filter) the same.
Below is schematic and board layout.