Hello,
according to the NXP website LPC540 and LPC546 are pin compatible. I also checked the pin mapping.
I got the MCU professionally reworked from LPC540 to LPC546.
My PCB is not working properly anymore now.
1. I can not talk to the MCU any more. The IDE cannot discover a target.
2. The power nets seem to be damaged. I can measure VCC vs GND as 3.3V. Some other nets that are connected to the MCU are on 0.9V, which they were not before.
Test:
1. Visual inspection: No obvious shorted nets.
2. Electrical tests: An external power supply draws 40 mA, which seems to be correct for the PCB.
3. A multi-meter indicates that there is a short between GND and VCC pins of the MCU.
My main question is: Is LPC540 and LPC546 truly compatible? That is, can I just switch them out on a PCB?
Thanks,
Jana
