公开(公告)号：US10298247B1

公开(公告)日：2019-05-21

申请号：US15919985

申请日：2018-03-13

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： Louis Frew ,  Kapil Sharma ,  David Paul Singleton ,  Andrew James Howlett

IPC: H03K7/08 ,  H03M1/06

Abstract: This application relates to analog-to-digital converter (ADC) circuitry (200). A time-encoding modulator (TEM 201) has a comparator (104) and a loop filter (105) configured to generate a pulse-width-modulated (PWM) signal (SPWM) in response to an input signal (SIN) and a feedback signal (SFB). A controlled oscillator, such as a VCO (202) receives the PWM signal and generates an output oscillation signal (SOSC) with a frequency that varies based on a drive signal at a drive node (109), e.g. a drive node of a ring oscillator (107). The controlled oscillator (202) comprises at least one control switch (112) controlled by a switch control signal (S1) generated from the received PWM signal so as to control the drive strength of the drive signal applied to the drive node (109). The feedback signal (SFB) for the TEM (201) is derived from the controlled oscillator (202) so as to include any timing error between the PWM signal and the switch control signal (S1) applied to said control switch.

公开(公告)号：US10254776B1

公开(公告)日：2019-04-09

申请号：US15851147

申请日：2017-12-21

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： David Paul Singleton ,  Kapil Sharma

IPC: G05F1/573 ,  H03M1/18 ,  G05F1/445

Abstract: This application relates to methods and apparatus for voltage regulation. Embodiments relate to signal processing circuit (300) having a first and second processing path with respective first and second inputs (INP and INN). The first and second processing paths have respective first and second virtual earth nodes (108P and 108N) at the input to a differential integrator (106). A differential feedback path is configured to apply a feedback signal to each of the first and second virtual earth nodes so as to minimize any voltage difference between them. A regulator (301) is operable to monitor a voltage at one of the virtual earth nodes (108P) against a reference voltage (VREF) and to generate a regulation signal to maintain the voltage at said monitored one of the first and second virtual earth nodes to be equal to the reference voltage. The regulation signal is applied to both of the first and second virtual earth nodes.