Data Sheet

ADRF5473

THEORY OF OPERATION

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Rev. 0 | 15 of 17

PARALLEL MODE INTERFACE

The ADRF5473 has six digital control inputs, D0 (LSB) to D5

(MSB), to select the desired attenuation state in parallel mode, as

shown in Table 7. The parallel control interface is activated when

PS is set to low.

There are two modes of parallel operation: direct parallel and

latched parallel.

Direct Parallel Mode

To enable direct parallel mode, the LE pad must be kept high. The

attenuation state is changed by the control voltage inputs (D0 to

D5) directly. This mode is ideal for manual control of the attenuator.

Latched Parallel Mode

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

changing the control voltage inputs (D0 to D5) to set the attenuation

state. When the desired state is set, toggle LE high to transfer

the 6-bit data to the bypass switches of the attenuator array, and

then toggle LE low to latch the change into the device until the

next desired attenuation change (see Figure 27 and Table 2 for

additional information).

Figure 27. Latched Parallel Mode Timing Diagram