Feedforward Compensation of the Amplifier Output Stage for Improved Stability with Capacitive Loads
نویسنده
چکیده
The stability margin of an audio power amplifier is reduced by a pole in the loopgain transfer function caused by shunt capacitance in the loudspeaker load. The problem is most severe in amplifiers with output stages that have a high output impedance before feedback. Because MOSFET devices can have an output impedance that is much higher than BJT devices, amplifiers with WFlT output stages are particularly susceptible to l&d induced oscillations. A feedforward frequency compensation technique is described which bypasses the pole in the output stage caused by the load capacitance for improved stability of the amplifier.
منابع مشابه
A Low-Voltage, Low-Power, Two-Stage Amplifier for Switched-Capacitor Applications in 90 nm CMOS Process
Abstract- A novel low-voltage two-stage operational amplifier employing resistive biasing is presented. This amplifier implements neutralization and correction common mode stability in second stage while employs capacitive dc level shifter and coupling between two stages. The structure reduces the power consumption and increases output voltage swing. The compensation is performed by simple mill...
متن کاملSingle Miller Compensation with Split Output and Current Amplifier (SMSOC) Use in Three Stage Amplifiers to Driving Ultra Large Capacitive Loads
In this paper, there is a combined approach which is used to compensate three stage amplifiers with ultra large capacitive loads and low power, using current mirror amplifier with split output is to decrease the occupied level of compensation capacitor that causes to lessen the occupied level of chip –area for using compensation capacitor and getting resulted in the light of better slew rate (S...
متن کاملHybrid cascode feedforward compensation for nano-scale low-power ultra-area-efficient three-stage amplifiers
A modified frequency compensation technique is proposed for low-power area-efficient three-stage amplifiers driving medium to large capacitive loads. Coined hybrid cascode feedforward compensation (HCFC), the total compensation capacitor is divided and shared between two internal high-speed feedback loops instead of only one loop as is common in prior art. Detailed analysis of this technique sh...
متن کاملSingle Miller Capacitor Feedforward Frequency Compensation on Three Stage Amplifier for Large Capacitive Load
This paper presents the analysis of single Miller capacitor feedforward compensation scheme which is used in threestage CMOS operational amplifiers. single Miller compensation capacitor in three-stage amplifiers can significantly reduce the total capacitor value, and therefore, the overall area of the amplifiers without influencing their stability. Feed forward technique is effectively combined...
متن کاملAdvances in RNMC Technique with Dual-Active Current and Voltage Buffer for High-Load Three- Stage Amplifiers
— This paper presents a novel compensation technique for low voltage low power three-stage amplifier driving large capacitive loads. The frequency bandwidth of this amplifier is improved due to usage of dual-active buffers in the efficient compensation network while a feed forward transconductance helps to enhance output large signal response. The paper provides a design procedure by developing...
متن کامل