Auxiliary Adc Slew Multiplexer; Blinking Led - Analog Devices AN-951 Application Note

AN-951

AUXILIARY ADC SLEW MULTIPLEXER

An analog input voltage can also be used to select between
sources (see Figure 31). In this example, an input voltage is
broken down into five equally-sized zones, each associated
with a different tone generator.
By multiplying the auxiliary ADC input signal by 5 in 28.0
format (implemented here as a DC input entry cell), the full
scale of the input is mapped to five index values: 0, 1, 2, 3, and
4 in 28.0 format, which are appropriate input values for the
multiplexer. The multiplexer cell uses this index to output the
appropriate sine tone.
The cell names as they appear in the software and the number
of each used in this example are as follows: ADC Input (1), DC
Input Entry (1), Multiply (1), Tone (lookup/sine) (5), Index
Selectable Slewing Mux (1), T Connection (1), and Output (2).

BLINKING LED

In the example shown in Figure 32, a square wave generator is
used to drive an output LED. Output GPIO pins turn off when
their associated register is equal to zero and turn on when equal
to any other value. By taking a square wave with a minimum
value of −1
result is a waveform with a minimum value of 0
value of 2
to that of the square wave generator (3 Hz in this example).
The cell names as they appear in the software and the number
of each used in this example are as follows: DC Input Entry (1),
Signal Add (1), Square Wave (1), and GPIO Output (1).
Figure 31. Auxiliary ADC Slew Multiplexer Signal Flow
Figure 32. Square Wave LED Driver Signal Flow
Rev. A | Page 14 of 20
Application Note
and a maximum of 1 , then adding 1
5.23 5.23
. This causes the LED to blink at a frequency equal
5.23
, the
5.23
, and maximum
5.23