A single-power-supply 10-b video BiCMOS sample-and-hold IC

Abstract

A +5-V single-power-supply 10-b video BiCMOS sampleand-hold IC is described. Video speed, low power, and 10-b accuracy sample-and-hold operation has been achieved using a complementary connected buffer format sample switch. A high-speed p-n-p transistor used in the sample switch is formed by a combination of n-p-n and PMOS transistors. The sample-and-hold operation is accomplished by feeding back the hold capacitor voltage to the sample switch inputs, so that the inputs transfer symmetrically for the hold capacitor voltage at any input level. The sample-and-hold IC has been implemented in 1.2-pm BiCMOS technology and evaluated. The following results have been obtained 185-MHz 3-dB bandwidth at 22-pF hold capacitor, 63-dB signal-to-noise ratio at 8-MHz full-scale input, 20-11s acquisition time at 1-V step input, 15-11s switching settling time, and 0.1% linearity error. Power dissipation is 150 mW.