US 6,556,160 B1 · Circuit for converting an analog signal to a PWM signal

Abstract

A circuit for converting an analog signal to a PWM signal samples an amplitude of the analog signal at first sampling rate and a second slower sampling rate, and produces corresponding first and second signals. A comparison signal defines a first state when the first signal is greater than the second signal, and otherwise defines a second opposite state. The PWM signal switches from a first signal level to a second signal level when the comparison signal switches from the first state to the second state only if the comparison signal thereafter remains in the second state for a specified delay period, and the PWM signal switches from the second signal level to the first signal level when the comparison signal switches from the second state to the first state only if the comparison signal thereafter remains in the first state for the delay period.

Claims22

Dependent claims

Circuitry for converting an analog signal to a PWM signal, the circuit comprising:

a first circuit configured to sample an amplitude of the analog signal at a first rate and produce a first signal corresponding thereto;
a second circuit configured to sample the amplitude of the analog signal at a second rate slower than said first rate and produce a second signal corresponding thereto;
a third circuit producing a third signal defining a first state when said first signal is greater than said second signal and otherwise defining a second opposite state;
and
a fourth circuit producing the PWM signal defining a pulse width as a function of a switching rate of said third signal between said first and second states.

2 more elements

Circuitry for converting an analog signal to a PWM signal, the circuit comprising:

a sampling circuit configured to sample an amplitude of the analog signal at two different rates and produce corresponding first and second signals;
a comparison circuit producing a comparison signal defining a first state when said first signal is greater than said second signal and otherwise defining a second opposite state;
and
a delay circuit producing the PWM signal as a function of said comparison signal and a control signal, the PWM signal switching from a first signal level to a second signal level when said comparison signal switches from said first state to said second state only if said comparison signal thereafter remains in said second state for a delay period defined by said control signal, and the PWM signal switching from said second signal level to said first signal level when said comparison signal switches from said second state to said first state only if said comparison signal thereafter remains in said first state for said delay period.

1 more element

Circuitry for converting an analog signal to a PWM signal, the circuit comprising:

a sampling circuit configured to sample an amplitude of the analog signal and produce a detection signal defining a first state upon detection of a peak in the amplitude of the analog signal, and defining a second opposite state upon detection of a valley in the amplitude of the analog signal;
and
a delay circuit producing the PWM signal as a function of said detection signal and a control signal, the PWM signal switching from a first signal level to a second signal level when said detection signal switches from said first state to said second state only if said detection signal thereafter remains in said second state for a delay period defined by said control signal, and the PWM signal switching from said second signal level to said first signal level when said detection signal switches from said second state to said first state only if said detection signal thereafter remains in said first state for said delay period.

Dependencies are inferred from the claim text.

Circuit for converting an analog signal to a PWM signal

Life of this patent

Circuit for converting an analog signal to a PWM signal

Life of this patent

Abstract

Claims22