Patent ID: 8618888
Filing Date: 2013-12-31
Classification: H03K,H03L

Abstract:
1. An apparatus comprising: a first circuit configured to generate an output signal oscillating at a frequency in response to a first control signal and a second control signal, wherein said first circuit comprises a ring oscillator circuit; and a second circuit configured to generate said second control signal at an output of an operational amplifier in response to (i) an input voltage received at a control input of said operational amplifier, (ii) a fixed voltage received at a first input of said operational amplifier, (iii) a swing voltage received at a second input of said operational amplifier and (iv) a power supply voltage, wherein said second circuit (i) generates (a) said second control signal and (b) said swing voltage in response to a replica delay cell configured to receive said first control signal, and (ii) adjusts an amplitude of said second control signal in response to said swing voltage.