ICD3 weird behavior

[hello188]

Hi. I am trying to connect ICD to my target board which has 3.3V power supply connected to PIC18F23K22.

When I tried to get my ICD3 to recognize the MCU using the on-board power supply(not from ICD3), it didn't recognize and gave target Device ID 0000 error.

However, when I tried using ICD3 to supply power, it worked, only when I set the power supply to 3.0V or lower. and did not work when I raise it to 3.3V, it doesn't work again.

Any idea??

Thanks

[Ttelmah]

Have you updated the firmware on the ICD3?. There is a patch needed to run properly with the 18F23K22.
What is your on board PSU (voltage, and current rating)?. These chips produce some nasty spikes when they start, which can cause supplies to oscillate, and boot to fail.
Is this the F23, or the LF23?.
What is your clock?. Frequency, and internal/external etc.

Best Wishes

[hello188]

My firmware for ICD3 is up-to-date, as I updated it using the latest version of MPLAB IDE.

my PSU is able to supply 150mA with load regulation of 65mV and line regulation of 30mV.

The part is F23, not LF23.
The frequency is 14.7456MHz using external oscillator.

I just assembled the second unit, and it works fine.

I don't know what could be wrong with the first one.

On both board, the MCU works fine as I programmed.

Thanks

[Ttelmah]

I'd begin to be suspicious of just a faulty chip.

However the nastiness of the supply wake-up could be the problem. Some of the chips produce nSec spikes drawing tens of mA, during the actual start-up, and the spikes are so narrow, they can make some sources have problems at this point (several really good HF capacitors right by the chip pins help).
This was why I asked about the clock, since on one chip I had, this stopped the crystal oscillator starting reliably at some voltages. With an external oscillator this shouldn't be a problem.

Best Wishes