Abstract: In an embodiment, a method for shaping a PWM signal includes: receiving an input PWM signal; generating an output PWM signal based on the input PWM signal by: when the input PWM signal transitions with a first edge of the input PWM signal, transitioning the output PWM signal with a first edge of the output PWM signal; and when the input PWM signal transitions with a second edge before the first edge of the output PWM signal transitions, delaying a second edge of the output PWM signal based on the first edge of the output PWM signal.

Abstract: In an embodiment, a method for shaping a PWM signal includes: receiving an input PWM signal; generating an output PWM signal based on the input PWM signal by: when the input PWM signal transitions with a first edge of the input PWM signal, transitioning the output PWM signal with a first edge of the output PWM signal; and when the input PWM signal transitions with a second edge before the first edge of the output PWM signal transitions, delaying a second edge of the output PWM signal based on the first edge of the output PWM signal.

Abstract: A filtering circuit for filtering a pulse width modulated (PWM) signal includes a D flip-flop having an input terminal configured to be coupled to a logic high signal and having an output terminal coupled to an output terminal of the filtering circuit; and a circuit coupled between an input terminal of the filtering circuit and the D flip-flop, the circuit configured to, for a first pulse of the PWM signal having a duty cycle within a pre-determined range: generate a positive pulse at a clock terminal of the D flip-flop as a clock signal of the D flip-flop; and generate a negative pulse at a reset terminal of the D flip-flop as a reset signal of the D flip-flop, wherein a duration between a rising edge of the positive pulse and a falling edge of the negative pulse is equal to a duration of the first pulse of the PWM signal.

Abstract: A filtering circuit for filtering a pulse width modulated (PWM) signal includes a D flip-flop having an input terminal configured to be coupled to a logic high signal and having an output terminal coupled to an output terminal of the filtering circuit; and a circuit coupled between an input terminal of the filtering circuit and the D flip-flop, the circuit configured to, for a first pulse of the PWM signal having a duty cycle within a pre-determined range: generate a positive pulse at a clock terminal of the D flip-flop as a clock signal of the D flip-flop; and generate a negative pulse at a reset terminal of the D flip-flop as a reset signal of the D flip-flop, wherein a duration between a rising edge of the positive pulse and a falling edge of the negative pulse is equal to a duration of the first pulse of the PWM signal.

Abstract: A circuit includes a field effect transistor having a gate driven via a drive signal. The field effect transistor has a drain-source voltage drop indicative of the intensity of a current flowing in the current path through the field effect transistor. The circuit also includes a pair of sensing transistors that include a first sensing field effect transistor arranged with its drain and gate coupled with the drain and the gate of the field effect transistor, respectively, and a second sensing field effect transistor having a gate configured for receiving a replica of the drive signal. The second sensing field effect transistor is arranged with its current path in series with the current path of the first sensing field effect transistor. A sensing signal at a sensing node is indicative of the current intensity flowing in the current path of the field effect transistor.

Abstract: A filtering circuit for filtering a pulse width modulated (PWM) signal includes a D flip-flop having an input terminal configured to be coupled to a logic high signal and having an output terminal coupled to an output terminal of the filtering circuit; and a circuit coupled between an input terminal of the filtering circuit and the D flip-flop, the circuit configured to, for a first pulse of the PWM signal having a duty cycle within a pre-determined range: generate a positive pulse at a clock terminal of the D flip-flop as a clock signal of the D flip-flop; and generate a negative pulse at a reset terminal of the D flip-flop as a reset signal of the D flip-flop, wherein a duration between a rising edge of the positive pulse and a falling edge of the negative pulse is equal to a duration of the first pulse of the PWM signal.

Abstract: A circuit includes a field effect transistor having a gate driven via a drive signal. The field effect transistor has a drain-source voltage drop indicative of the intensity of a current flowing in the current path through the field effect transistor. The circuit also includes a pair of sensing transistors that include a first sensing field effect transistor arranged with its drain and gate coupled with the drain and the gate of the field effect transistor, respectively, and a second sensing field effect transistor having a gate configured for receiving a replica of the drive signal. The second sensing field effect transistor is arranged with its current path in series with the current path of the first sensing field effect transistor. A sensing signal at a sensing node is indicative of the current intensity flowing in the current path of the field effect transistor.

Abstract: A class-D amplifier includes a signal processing block. The signal processing block generates a first processed signal representing a difference between a first differential signal and a second differential signal, when a duty cycle of the first differential signal is greater than that of the second differential signal. The signal processing block generates the first processed signal representing a reference DC level, when the duty cycle of the first differential signal is less than that of the second differential signal. A second processed signal representing a difference between the second differential signal and the first differential signal is generated when the duty cycle of the second differential signal is greater than that of the first differential signal, and the second processed signal representing the reference DC level is generated when the duty cycle of the second differential signal is less than that of the first differential signal.

Abstract: Limiting clipping in an amplifier is accomplished in the feedback loop of a class D PWM amplifier that includes an integrator coupled to an input node and configured to generate an integrated input signal such that a comparator may then generate a PWM signal for driving an amplifier output stage based on a comparison to a triangle wave signal. To this end, the amplifier also includes a threshold signal generator for generating high and low voltage thresholds based on the triangle wave signal to be used to engage compensation circuits for limiting the overall amplification. Such compensation circuits may be bipolar junction transistors that are disposed in the feedback loop of the integrator. Thus, the overall bandwidth of the amplifier itself is not affected by adding a limiter circuit aimed at reducing clipping.

Abstract: A class-D amplifier includes a signal processing block. The signal processing block generates a first processed signal representing a difference between a first differential signal and a second differential signal, when a duty cycle of the first differential signal is greater than that of the second differential signal. The signal processing block generates the first processed signal representing a reference DC level, when the duty cycle of the first differential signal is less than that of the second differential signal. A second processed signal representing a difference between the second differential signal and the first differential signal is generated when the duty cycle of the second differential signal is greater than that of the first differential signal, and the second processed signal representing the reference DC level is generated when the duty cycle of the second differential signal is less than that of the first differential signal.

Abstract: Limiting clipping in an amplifier is accomplished in the feedback loop of a class D PWM amplifier that includes an integrator coupled to an input node and configured to generate an integrated input signal such that a comparator may then generate a PWM signal for driving an amplifier output stage based on a comparison to a triangle wave signal. To this end, the amplifier also includes a threshold signal generator for generating high and low voltage thresholds based on the triangle wave signal to be used to engage compensation circuits for limiting the overall amplification. Such compensation circuits may be bipolar junction transistors that are disposed in the feedback loop of the integrator. Thus, the overall bandwidth of the amplifier itself is not affected by adding a limiter circuit aimed at reducing clipping.

Abstract: An oscillator module includes a first MOS transistor and a capacitor. The capacitor is coupled between a gate and source of the first MOS transistor. The drain of the first MOS transistor receives a first bias current and generates an oscillating output signal. A switching circuit operates in response to the oscillating output signal to selective charge and discharge the capacitor. A current sourcing circuit is configured to generate the bias current. The current sourcing circuit includes a second MOS transistor which has an identical layout to the first MOS transistor and receives a second bias current. A resistor is coupled between a gate and source of the second MOS transistor. The current sourcing circuit further includes a current mirror having an input configured to receive a reference current passing through the resistor and generate the first and second bias currents.

Abstract: A circuit includes a first circuit module with a first input node, a second input node and an output node. The first circuit module receives an input signal at the first input node and generates an amplified signal at the output node. The circuit further includes a second circuit module coupled between the output node and a reference potential line. The second circuit selectively draws a current from the output node in response to a first control signal. The first control signal is generated in response to sensing a voltage fluctuation at a power supply node which supplies power to the first circuit module.

Abstract: An oscillator module includes a first MOS transistor and a capacitor. The capacitor is coupled between a gate and source of the first MOS transistor. The drain of the first MOS transistor receives a first bias current and generates an oscillating output signal. A switching circuit operates in response to the oscillating output signal to selective charge and discharge the capacitor. A current sourcing circuit is configured to generate the bias current. The current sourcing circuit includes a second MOS transistor which has an identical layout to the first MOS transistor and receives a second bias current. A resistor is coupled between a gate and source of the second MOS transistor. The current sourcing circuit further includes a current mirror having an input configured to receive a reference current passing through the resistor and generate the first and second bias currents.

Abstract: A circuit includes a first circuit module with a first input node, a second input node and an output node. The first circuit module receives an input signal at the first input node and generates an amplified signal at the output node. The circuit further includes a second circuit module coupled between the output node and a reference potential line. The second circuit selectively draws a current from the output node in response to a first control signal. The first control signal is generated in response to sensing a voltage fluctuation at a power supply node which supplies power to the first circuit module.

Abstract: A charge pump circuit includes a first power transistor selectively actuated by a first control signal to deliver relatively higher amounts of current to a capacitor and a second non-power transistor connected in parallel with the first power transistor and selectively actuated by a second control signal to deliver relatively lower amounts of current to the capacitor. The charge pump circuit includes a pumped voltage output that is sensed to generate a sensed voltage output. A comparison circuit compares the sensed voltage output to a threshold voltage. A logic circuit receives an output of the comparison circuit and enables the first power transistor and disables the second non-power transistor in a first mode of operation if the comparison is not satisfied. The logic circuit further disables the first power transistor and enables the second non-power transistor in a second mode of operation if the comparison is satisfied.

Abstract: A charge pump circuit includes a first power transistor selectively actuated by a first control signal to deliver relatively higher amounts of current to a capacitor and a second non-power transistor connected in parallel with the first power transistor and selectively actuated by a second control signal to deliver relatively lower amounts of current to the capacitor. The charge pump circuit includes a pumped voltage output that is sensed to generate a sensed voltage output. A comparison circuit compares the sensed voltage output to a threshold voltage. A logic circuit receives an output of the comparison circuit and enables the first power transistor and disables the second non-power transistor in a first mode of operation if the comparison is not satisfied. The logic circuit further disables the first power transistor and enables the second non-power transistor in a second mode of operation if the comparison is satisfied.