AD9649 Chip configuration registers


I have a question AD9649 configuration registers.

1. What is mean stripes?

2.How to use couldn't be understood about a register of address 0x19-0x1C.

   If you know please teach me.

Best Regards


  • 0
    •  Analog Employees 
    on Jun 17, 2017 7:28 AM

    Hi HOD,

    I apologize for the late reply!

    1. “Stripes” refers to the quantity of transistor stacks or "stripes" that are enabled for a given drive strength setting. More “stripes” means that more drivers are driving in parallel and thus result in a greater drive strength. Please refer to the discussion on this topic found here: . This is for AD9251, which is the dual version of AD9649, but the same principle applies.
    2. Register 0x19 through Register 0x1C are for storing patterns of your choice, for outputting at the AD9649 output pins when "user input" is selected by Register 0x0D (see below).


    Write Register 0x19 = 0x0F (write 00001111 to Bits[7:0])

    Write Register 0x1A = 0xF0 (write 11110000 to Bits[7:0])

    Write Register 0x0D = 0x08 (select "user input" test mode)

    Write Register 0xFF = 0x01 (transfer bit to actualize the above SPI writes)

    Now 1111 0000 0000 11 will appear on the outputs.

    The last two 1s will be truncated because the AD9649 is a 14bit part (not 16bit).

    Again, I apologize for the late reply.