Zero-voltage switching in switched current circuits

Traditionally the accuracy of switched-current circuits has been much lower than that of switched-capacitor circuits. To address this problem, an accurate high-speed switched-current sample-and-hold technique based on zero-voltage switching is presented. The technique significantly reduces the signal dependent charge injection, leading to improved sampling accuracy. To demonstrate the proposed technique, a sample-and-hold has been implemented using a 1.2 μm CMOS process. The circuit is expected to achieve 14 bit linearity at sampling rates exceeding 50 M Samples/sec. While dissipating only 3.5 mW from a nominal 3.3 V supply