Systems with ADC circuitry and associated methods

Systems with object detection capabilities may include a radio detection and ranging (RADAR) system. The RADAR system or other portions of the systems may include analog-to-digital converter circuitry. The analog-to-digital converter circuitry may be implemented as pipeline analog-to-digital converter circuitry having multiple stages. Each stage may include multiplying digital-to-analog converter circuitry having a sampling network and amplifier circuitry. The amplifier circuitry may be shared be shared between multiple stages. The amplifier circuitry may include cascodes for switching between different input pairs from corresponding sampling networks in corresponding stages. The amplifier circuitry may generate amplifier outputs for a first sampling network while the other sampling network performs sampling operations. This may minimize non-amplification time for the amplifier circuitry reduce power consumption in the converter circuitry. The amplifier circuitry may also include shorting switches that bring the amplifier output to a common mode voltage to more improve output slew characteristics.