Author Topic: no quarz oscillator on MRDS1322  (Read 206 times)

Gianni Picconi

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no quarz oscillator on MRDS1322
« on: September 07, 2018, 06:36:14 pm »
Good evening I have a problem,
I bought 4 pieces of the MRDS1322 but on pins 2 and 3 I do not have the frequency of oscillation
thanks in advance for your cooperation
Gianni

Jan

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Re: no quarz oscillator on MRDS1322
« Reply #1 on: September 07, 2018, 08:05:02 pm »
Only high input impedance counter can be connected to these pins. Thus I would recommend to measure on pin 5 rather. There should be 57 kHz @ 5 Vpp.

Please post your schematic diagram or better a photo of the board.


Jan

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Re: no quarz oscillator on MRDS1322
« Reply #3 on: September 08, 2018, 12:12:05 pm »
The C1 and C2 must be placed.

The XTAL pins may be short-circuited by the XTAL case - place the XTAL a few mm above the board or use an insulation pad.

Minimum configuration for getting the oscillator working is:

Pin 1: +5V
Pin 2: XTAL + 22 pF capacitor to GND
Pin 3: XTAL + 22 pF capacitor to GND
Pin 4: +5V via a resistor
Pin 20: GND