Data Sheet

ADRF5740

Rev. 0 | Page 11 of 13

PARALLEL MODE INTERFACE

There are two modes of parallel operation: direct parallel and

latched parallel.

Direct Parallel Mode

To enable direct parallel mode, keep the LE pin high. To change

the attenuation state, use the control voltage inputs (D2 to D5)

directly. Direct parallel mode is for manual control of the

attenuator.

Latched Parallel Mode

To enable latched parallel mode, keep the LE pin low when

changing the control voltage inputs (D2 to D5) to set the

attenuation state. The LE pin is level triggered. When the

desired attenuation state is set, toggle LE high to transfer the

data to the bypass switches of the attenuator array. Then, toggle

LE low to secure the change into the device until the next required

attenuation change.

D5 TO D2

LE

X

X

Figure 24. Latched Parallel Mode Timing Diagram