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

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 250 mum by 160 mum in 0.35 mum 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. 50 V . Implemented switch can reliably track and hold 20 V
_PP
signal on 15 V
_DC
at 1 MS/s with 2.2 V supply without forward biasing any parasitic diode. A designed switched capacitor attenuator utilizing proposed high voltage switch can process 20 V
_PP
differential input reliably.