6

AN314REV1

AN314

5. SELECTING AN AMPLIFIER

If an amplifier is needed to change the full-scale range or to buffer the inputs and it is placed between the MUX and

the ADC, one of the most critical parameters will be settling time. However, as mentioned above, if the amplifier is

placed before the MUX (one on each input of the MUX where needed) this requirement is greatly relaxed. In this-

case, signal-to-noise, distortion, DC offset, and stability over temperature become the primary selection criteria for

most applications. Each application will determine which parameters are most critical so it becomes difficult to spec-

ify an op-amp and circuit configuration that will work in all situations. The CS3003 and CS3004 operational ampli-

fiers will be suitable for many applications due to their excellent DC performance, moderate bandwidth, and low

noise.

6. OPTIMIZED CIRCUITS FOR MULTIPLEXING CS556X/7X/8X ADCs

The following are examples of circuits that optimize the performance of the CS556x/7x/8x family of high-throughput

ADCs for a number of general-purpose applications. Each circuit is followed by a brief circuit description with the

key selection criteria noted.