Abstract:
A Schmitt trigger circuit having an input coupled to a current summing junction. A trickle current source generates a trickle current applied to the current summing junction. A bandgap current source generates a bandgap current applied to the current summing junction (wherein the bandgap current is fixed when a supply voltage exceeds a threshold). A variable current source generates a variable current applied to the current summing junction (wherein the variable current varies dependent on the supply voltage). At the current summing junction, the variable current is offset against the trickle and bandgap currents with respect to generating a voltage that is sensed at the Schmitt trigger circuit input.
Abstract:
A circuit can be used in a speaker system. The circuit includes an amplifier with an output configured to be coupled to a speaker. An offset comparator has an input coupled the output of the amplifier and is configured to provide an offset control signal. A digital circuit has a first input coupled to an output of the offset comparator, a second input configured to receive an amplifier control signal, a third input configured to receive a play control signal, and an output configured to provide a forced mute signal that can be used to control the amplifier.
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:
A proximity detector device may include a first interconnect layer including a first dielectric layer, and first electrically conductive traces carried thereby, an IC layer above the first interconnect layer and having an image sensor IC, and a light source IC laterally spaced from the image sensor IC. The proximity detector device may include a second interconnect layer above the IC layer and having a second dielectric layer, and second electrically conductive traces carried thereby. The second interconnect layer may have first and second openings therein respectively aligned with the image sensor IC and the light source IC. Each of the image sensor IC and the light source IC may be coupled to the first and second electrically conductive traces. The proximity detector device may include a lens assembly above the second interconnect layer and having first and second lenses respectively aligned with the first and second openings.
Abstract:
An electronic device disclosed herein includes a current comparator to generate an output current based upon a difference between a current flowing in an output branch and a current flowing in an input branch. A pair of transistors is coupled to an output of the current comparator. A first amplifier has inputs coupled to the pair of transistors and to a reference voltage, the first amplifier being configured to subtract the reference voltage from a voltage across the pair of transistors and output a difference voltage. A second amplifier has inputs coupled to the difference voltage and to the reference voltage, the second amplifier being configured to subtract the difference voltage from the reference voltage and output a pulse skipping mode reference signal.
Abstract:
Current flowing through an inductor in response to a pulse width modulation (PWM) control signal is sensed to generate a sensed current. The sensed current is processed over one or more PWM cycles of the PWM control signal to generate an output signal indicative of average inductor current. This processing may include charging and discharging a capacitor at different rates dependent on the sense current, with the detection of capacitor discharge triggering a sampling of a voltage dependent on the sensed current that is indicative of average inductor current. The processing may include using the sensed to current to generate a first charge voltage associated with minimum inductor current and a second charge voltage associated with maximum inductor current, and then averaging the first and second charge voltages to generate an output signal indicative of average inductor current.
Abstract:
A charge pump circuit is coupled between a positive supply node and a ground node. The charge pump circuit operates in response to clock signals output from a clock generator to produce a negative voltage at a negative voltage output node. A soft-start circuit for the charge pump circuit includes a comparison circuit configured to compare a varying intermediate voltage sensed between a rising supply voltage and the negative voltage to a ramp voltage during a start-up period of the charge pump circuit. The clock generator is selectively enabled to generate the clock signals in response to the comparison to provide for pulse-skipping.
Abstract:
A Schmitt trigger circuit having an input coupled to a current summing junction. A trickle current source generates a trickle current applied to the current summing junction. A bandgap current source generates a bandgap current applied to the current summing junction (wherein the bandgap current is fixed when a supply voltage exceeds a threshold). A variable current source generates a variable current applied to the current summing junction (wherein the variable current varies dependent on the supply voltage). At the current summing junction, the variable current is offset against the trickle and bandgap currents with respect to generating a voltage that is sensed at the Schmitt trigger circuit input.
Abstract:
A class D amplifier receives and amplifies a differential analog signal which is then differentially integrated. Two pulse width modulators generate pulse signals corresponding to the differentially integrated analog signal and two power units generate output pulse signals. The outputs the power units are coupled to input terminals of integrators via a resistor feedback network. An analog output unit converts the pulse signals to an output analog signal. The differential integration circuitry implements a soft transition between mute/un-mute. In mute, the integrator output is fixed. During the soft transition, the PWM outputs change slowly from a fixed 50% duty cycle to a final value to ensure that no pop noise is present in the output as a result of mode change.
Abstract:
An electronic device disclosed herein includes a current comparator to generate an output current based upon a difference between a current flowing in an output branch and a current flowing in an input branch. A pair of transistors is coupled to an output of the current comparator. A first amplifier has inputs coupled to the pair of transistors and to a reference voltage, the first amplifier being configured to subtract the reference voltage from a voltage across the pair of transistors and output a difference voltage. A second amplifier has inputs coupled to the difference voltage and to the reference voltage, the second amplifier being configured to subtract the difference voltage from the reference voltage and output a pulse skipping mode reference signal.