25V sampling switch for power management data converters in 0.35µm CMOS with DNMOS

Abstract

A new high-voltage bootstrapped sampling switch with input signal range exceeding 11 times its supply voltage is presented. Proposed switch occupies a silicon area of 250µm by 160µm in 0.35µm twin-well CMOS process with drain extended NMOS (DNMOS) capability. The switch safe input signal range is restricted only by the DNMOS drain terminal breakdown voltage, i.e. 50V . Implemented switch can reliably track and hold 20VPP signal on 15VDC at 1MS/s with 2.2V supply without forward biasing any parasitic diode. A designed switched capacitor attenuator utilizing proposed high voltage switch can process 20VPP differential input reliably.