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HMC365 outputs levels are PECL compatible ?

Question asked by baciccia on Jul 12, 2015
Latest reply on Jul 15, 2015 by MRichardson

Hello, I am working about a prescaler using an HMC365S8G followed by an ECL divider by 4 as high side of enclosed pdf schematic.

The questions are:

1)  If I use a differential output termination for the HMC365 the common mode DC voltage is the same for both output, then may I      eliminated the outputs capacitors ?

2)  From the HMC365 datasheet ( page 3 ) I see ' VLogic  Vcc-1.6V to Vcc-1.2V' , if this is the DC output level of the device it seem to be

     compatible with the input bias level of the ECL prescaler ( about Vcc-1.3V to Vcc- 1.4V), so may I eliminated the input bias circuits and

     directly connect to HMC365 outputs ?

The device output power (4-6 dBm corresponding to 1.00 -1.26 Vpp) is ok for the ECL divider inputs.

If these modifications are possible the schematic turn out as the bottom side of the enclosed pdf, more simple and more RF advantageous

(without the bias and DC blocking capacitor the 100Ohm termination can be put close to the ECL divider inputs).

I ask all this because prototyping at these frequencies is expensive both in time and money ( an 'ad hoc' pcb is need for each solution, not easy breadboard allowed !).

In advance thanks for any comments, best regards

Baciccia

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