Abstract: Closed loop voltage clamp circuits and related methods are disclosed that can be used in a variety of applications including USB (Universal Serial Bus) Type-C connections. The voltage clamp embodiments operate to clamp a voltage on a circuit node. A driver stage is coupled between the circuit node and ground. A pass circuit stage is coupled between the circuit node and ground, has a control node coupled to the output of the driver stage, and is configured to control the voltage on the circuit node. The feedback amplifier stage is coupled between the circuit node and ground and has an output node coupled to the input node of the driver stage. The driver stage, the pass circuit stage, and the feedback amplifier stage operate as a closed loop circuit without reference voltage and supply voltage connections.

Abstract: In an example embodiment, an apparatus includes: a first sampling capacitor to switchably couple between an input analog voltage, a reference voltage (VREF) and a ground voltage; a second sampling capacitor to switchably couple between the reference voltage and the ground voltage; and a comparator having a first input terminal to couple to the first sampling capacitor and a second input terminal to couple to the second sampling capacitor. The comparator may be configured to compare a voltage level at the second input terminal to a sum voltage based at least in part on the input analog voltage to generate at least one bit of a digital output.