WM2617
First,
0d01 1111 1111 11xx
Production Data
is written (bit D15 on the left, D0 on the right) to the serial interface. This loads the full-scale code
into the double buffer but does not change the latch B contents and the DAC B output voltage.
The latch A contents and the DAC A output are also unaffected by this write operation.
Changing from fast to slow to fast mode changes the supply current which can glitch the outputs,
and so D14 (designated by d in the above data word) should be set to maintain the speed mode
set by the previous write.
Next,
1d0X 1000 0000 00xx
is written (bit D15 on the left, D0 on the right) to the serial interface. Bit D14 can be zero to select
slow mode or one to select fast mode. The X in bit D12 can be zero or one (don’t care). This
writes the mid-scale code (100000000000) to latch A and also copies the full-scale code from the
double buffer to latch B. Both DAC outputs thus begin to rise after the second write.
WOLFSON MICROELECTRONICS LTD
PD Rev 1.1 October 2000
9
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
