GΩ Resistor for AC-coupled Amplifier in Audio Application

AC-coupled amplifiers (ACCA) offer lower noise than traditional resistor feedback amplifiers, which benefits signal-to-noise ratio (SNR) for audio applications. Due to the DC isolation of the capacitor, a feedback resistor is needed to set the virtual ground of ACCA’s amplifier. However, an external feedback resistor raises system noise and...

Wide Dynamic-range Low-power current-mode Optical Sensor Readout

Optical sensor has been widely used in daily life. One of the important applications of optical sensors is the ambient light sensor installed in portable devices. The screen brightness of portable devices like smartphones is designed to be automatically adjusted based on the ambient environment. The ambient light detection is realized using...

High-Dynamic-Range, Low-Power Digital-Input Direct-PWM Class-D Amplifier

Class-D amplifiers are quickly becoming the standard in many audio applications. Their highly efficient behavior and wide power range make these amplifiers more suitable than traditional Class A/AB audio amplifiers. Battery-powered devices are a particularly interesting sub-field due to their special demand for extended battery duration and...

A Class-D amplifier architecture to compensate for the instability problem due to the LC filter variation

Class D audio amplifier is widely used in many electronic applications such as automobiles, laptops, and mobile phones. However, electromagnetic interference (EMI) generated by Class-D audio amplifiers frequently requires an external LC filter for suppression. The LC filter itself causes significant nonlinearity. Hence, feedback after LC is...

Chopper PWM-Based Class-D Amplifier

Class-D amplifiers are widely used in audio applications that require a high power efficiency. A high PSRR is beneficial when the power supply contains significant audio band content. Due to mismatches present in the feedback, these can dominate the PSRR of the class-D amplifier, provided the amplifier has sufficient loop gain. No literature has...

Single Electron Readout Circuit: SERCuit

Particle detection circuits are used for a wide range of applications from experimental physics to material testing and medical imaging. State-of-the-art imaging systems demand the detection of small amounts of charge with small time-resolution and limited power consumption, creating an implementation dead-end for the typical readout topology....

Ultra-Low Idle Power Class-D Amplifier

Class-D amplifiers are widely used in automotive audio systems because of their high efficiency. In modern car sound systems, multiple amplifiers are used to provide good audio effect. However, typical class-D amplifiers have a high idle-power, which can drain the battery quickly. To solve this problem, an ultra-low idle power class-D amplifier...

Galvanic Isolation Communication Link

Digital isolators are devices that connect one electrical system block to another over a galvanically isolating barrier. They allow electrical systems to communicate with each other even though they may operate at vastly different potentials. They also do the job of eliminating potentially damaging ground loops between the two systems. This...

A 2.1MHz PWM Based Class D Audio Amplifier

This work presents a fully differential Class D audio amplifier using 2.1MHz pulse-width modulation (PWM) frequency and 425kHz LC filter cut-off frequency to decrease the cost of off-chip components. Moreover, feedback after LC filter structure is used to attenuate LC filter nonlinearities.