Patent ID: 8791682
Filing Date: 2014-07-29
Classification: H03F

Abstract:
1. An apparatus comprising: a pass element comprising an input, an output and a control input, said pass element being configured to be operable in a first mode, with a first signal on said control input, for substantially passing a voltage from said input to said output and to be operable in a second mode, with a second signal on said control input, for substantially blocking the voltage on said input from passing to said output; a differential amplifier comprising a non-inverting input coupled to said input, an inverting input coupled to said output, an amplifier output coupled to said control input and a bias current connection, said differential amplifier being configured to be operable in a first mode, with a bias current supplied to said bias current connection, for supplying said first signal along with a closed feedback loop from said output where an amount of noise on said input is rejected and to be operable in a second mode for supplying said second signal in absence of said bias current; and a current source comprising a current source output coupled to said bias current connection and an enable input, said current source being configured to be operable in a first mode, with an enable signal present on said enable input, for supplying said bias current and to be operable in a second mode, in absence of said enable signal, for disabling said supplying of said bias current.