Programming LTC2636

Hi,

What variant of the LTC2636 are you using? (-12, -10, -8) You should be sending out 24 clock edges for a valid transaction. Can you send a scope shot of your CS, SCK, and SDI signals?

What voltage are you supplying on the REF pin? Can you confirm if that is the actual voltage on the pin?

Best regards,

Ian

I am actually sending out 32 bit clock the second word is 0, and it is confirmed on logic analyzer

Vref = 3 V

Thanks

Here is the first command, 0x70000000, 32 bit, I think I need to change it back to 24 bit

Hi,

32bits should be fine, but you need to follow Figure 3b on the datasheet. 
"To use the 32-bit width, 8 don’t-care bits must be transferred to the device first, followed by the 24-bit sequence described. Figure 3b shows the 32-bit sequence."

Thanks! 

Is there a way to tri-state the outputs? When I power it down, it seems to go to ground instead