I need your help.
I am using an ADE7753 IC in a design with a Voltage Transformer (VT) for voltage sensing and a Current Transformer for current.
The all system is being powered by the USB port from a PC through a JTAG interface.
The system is working perfectly except for two situations that i have recently found out:
1- When the PC is being powered by the battery:
- I connect the mains (230V 50Hz) and the system (ADE7753, MCU ... ) is OK.
- I disconnect the mains and reconnect, and the ADE7753 became down (No response). It recovers through a reset.
2- When the PC is working on mains:
- I connect the mains and the all system (MCU and ADE7753) became down. It recovers through a reset (disconect and connect the USB cable).
In the PCB design for the ADE7753 i use separate ground planes (AGND and DGND) and both are connected at one point though a ferrite bead. Both DVDD and AVDD are conected to 5V. The mid point of the VT is connected to AGND.
Thanks in advance for your support,