
sample or hold mode, or the switch to hold mode may occur automatically when a
conversion is started.
Microprocessor Interfacing
Output Coding
The examples used so far have been based on binary codes, where each bit in the
result represents a voltage value and the sum of these voltages in the output word
is the analog input voltage value. Some ADCs produce 2’s complement outputs,
where a negative voltage is represented by a negative 2’s complement value. A
few ADCs output values in BCD. Obviously this requires more bits for a given
range; a 12-bit binary output can represent values from 0 to 4095, but a 12-bit
BCD output can only represent values from ...