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AD9516-1 LVPECL clock generation

Question asked by mutual.jun on May 6, 2018
Latest reply on May 9, 2018 by mutual.jun

Hello,

I want to make DAC clock 500 MHz in AD9135-FMC-EBZ. The AD9135-FMC-EBZ has AD9516 clock generator. 

The OUT1 of AD9516 is connected to the clock pin of AD9135 in schematics.

According to the document that the input clock of AD9516 is 250 MHz from J1 connector and bypass it to the input of AD9135. The spi code for AD9516 is as follow.

How should I change it? 

 

------------------------------ code below -----------------------------

void Config_Clock(unsigned char slave_num)

{
   spiWrite (0x0000, 0xBD, slave_num); // Soft reset and Set SDO active
   spiWrite (0x0000, 0x99, slave_num); // Release reset and set SDO active
   spiWrite (0x01E1, 0x09, slave_num); // Power down VCO, bypass VCO divider and select CLK as source for channel divider
  // divider 0 is out 0/1, divider 1 is out2/3(not use), divider 2 is out4/5(not use)
   spiWrite (0x0192, 0x00, slave_num); // Connect OUT0 and OUT1 directly to divider 0
   spiWrite (0x0191, 0x80, slave_num); // Bypass divider 0

  // divier 3
   spiWrite (0x0199, 0x33, slave_num); // Set divider 3.1 for sysref to /8 = 250/8 = 31MHz (LMFC frequency)
   spiWrite (0x019C, 0x20, slave_num); // Bypass divider 3.2

  // divier 4
   spiWrite (0x01A1, 0x30, slave_num); // Bypass divider 4.1 & 4.2
   spiWrite (0x00F1, 0x0C, slave_num); // Set LVPECL for output 1 on, non inverting output, Vod=960mV
   spiWrite (0x0140, 0x42, slave_num); // Power on and set LVDS for output 6, non inverting output, driver current 3.5mA
   spiWrite (0x0141, 0x42, slave_num); // Power on and set LVDS for output 7, non inverting output, driver current 3.5mA
   spiWrite (0x0143, 0x42, slave_num); // Power on and set LVDS for output 9, non inverting output, driver current 3.5mA
   spiWrite (0x0232, 0x01, slave_num); // Update all register, self clearing
}

 

Best regards

Jun.

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