signal processing asp and dsp

Signals may be processed using analog techniques (analog signal processing, or
ASP), digital techniques (digital signal processing, or DSP), or a combination of
analog and digital techniques (mixed signal processing, or MSP). In some cases, the
choice of techniques is clear; in others, there is no clear cut choice, and second-order
considerations may be used to make the final decision.
With respect to DSP, the factor that distinguishes it from traditional computer
analysis of data is its speed and efficiency in performing sophisticated digital
processing functions such as filtering, FFT analysis, and data compression in real
The term mixed signal processing implies that both analog and digital processing is
done as part of the system. The system may be implemented in the form of a printed
circuit board, hybrid microcircuit, or a single integrated circuit chip. In the context
of this broad definition, ADCs and DACs are considered to be mixed signal
processors, since both analog and digital functions are implemented in each. Recent
advances in Very Large Scale Integration (VLSI) processing technology allow
complex digital processing as well as analog processing to be performed on the same
chip. The very nature of DSP itself implies that these functions can be performed in
Re: signal processing asp and dsp

It is impossible to process
real-world analog signals using purely digital techniques, since all sensors
(microphones, thermocouples, strain gages, microphones, piezoelectric crystals, disk
drive heads, etc.) are analog sensors. Therefore, some sort of signal conditioning
circuitry is required in order to prepare the sensor output for further signal
processing, whether it be analog or digital. Signal conditioning circuits are, in
reality, analog signal processors, performing such functions as multiplication (gain),
isolation (instrumentation amplifiers and isolation amplifiers), detection in the
presence of noise (high common-mode instrumentation amplifiers, line drivers, and
line receivers), dynamic range compression (log amps, LOGDACs, and
programmable gain amplifiers), and filtering (both passive and active).