公开(公告)号：US10651868B2

公开(公告)日：2020-05-12

申请号：US16233581

申请日：2018-12-27

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： Sri Ram Gupta

IPC: H03M1/50 ,  H03K3/03 ,  H03K5/24 ,  H03K3/012 ,  H03K7/08 ,  H03K19/21

Abstract: This application relates to modulators for providing time-encoded signals and in particular PWM signals. A modulator (200) has a first controlled oscillator (201P) configured to receive a first oscillator driving signal and output a first oscillation signal (S1). An accumulator (204) is configured to provide an accumulator value (VAL) based on a number of pulses of the first oscillation signal and a hysteretic comparator (205) alternates between first and second output states based on a hysteretic comparison of the accumulator value with a defined reference (REF). The first oscillator driving signal is based on a combination of an input signal and a feedback signal derived from an output of the hysteretic comparator. A second controlled oscillator (201N) may be configured to receive a second oscillator driving signal and output a second oscillation signal (S2) and the accumulator may provide the accumulator value based on a difference in the number of pulses of the first oscillation signal and the second oscillation signal.

公开(公告)号：US10171101B1

公开(公告)日：2019-01-01

申请号：US15882347

申请日：2018-01-29

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： Sri Ram Gupta

IPC: H03K3/03 ,  H03K5/24 ,  H03M1/50 ,  H03K19/21 ,  H03K3/012

Abstract: This application relates to modulators for providing time-encoded signals and in particular PWM signals. A modulator (200) has a first controlled oscillator (201P) configured to receive a first oscillator driving signal and output a first oscillation signal (S1). An accumulator (204) is configured to provide an accumulator value (VAL) based on a number of pulses of the first oscillation signal and a hysteretic comparator (205) alternates between first and second output states based on a hysteretic comparison of the accumulator value with a defined reference (REF). The first oscillator driving signal is based on a combination of an input signal and a feedback signal derived from an output of the hysteretic comparator. A second controlled oscillator (201N) may be configured to receive a second oscillator driving signal and output a second oscillation signal (S2) and the accumulator may provide the accumulator value based on a difference in the number of pulses of the first oscillation signal and the second oscillation signal.