Negative-Feedback-Circuit Arrangements TRIZ Cases

A parallel resonator with one operational amplifier enables high-order CTDS ADC transfer characteristics while cutting circuit size and power.

Sequentially powering an auxiliary stage before the main amplifier suppresses startup transients and avoids click and pop noise.

A differential detector and comparator calibrate the AM path in an EDGE polar transmitter, improving efficiency without diode drift.

Low-rate output sampling identifies PA nonlinearity for adaptive predistortion, cutting spectral regrowth without high-rate hardware.

A feedback filter and buffer make the receiver input-selective, rejecting strong interferers early to improve sensitivity and noise figure.

A two-stage capacitive amplifier lowers MEMS microphone output impedance to reduce attenuation, reject EMI, and improve noise performance.

Multiple analog feedback loops with integrators and PWM suppress Class-D amplifier noise, distortion, and supply-induced output errors at low power.

A parallel input stage with capacitive coupling suppresses negative feedback at high frequencies, raising peaking gain while limiting distortion.

Capacitive cross-coupling and AC coupling cut total capacitance, chip area, and power while preserving loop gain and stability in multipath op-amps.

A self-coupled step-up transformer boosts feedback gain to widen input matching bandwidth while suppressing out-band interference and preserving linearity.

Selective DAC activation matches DC offset compensation to amplifier gain, cutting unnecessary noise in low-gain stages.

Shared DC current paths and a common coupling point let a three-stage transistor circuit keep gain high under low-voltage supply.

A capacitive feedback impedance matched to amplifier input impedance limits loop phase shift, preventing oscillation and preserving gain.

Coordinated feedback impedance, compensation impedance, and current control keep amplifier bandwidth stable as gain changes while lowering power use.

Varying the phase of constant-width pulses spreads RF interference while preserving regular sampling and low output distortion in a switching amplifier.

Selective Class AB and switchmode stage operation cuts quiescent loss, while interleaved switching reduces ripple current and preserves audio quality.

A supply-dependent clock and PWM correction loop stabilize D-class amplifier output without regulators, cutting power loss, size, and weight.

A 3-level quantizer controls rail switching only at defined signal states, cutting amplifier power use while preserving sigma-delta audio quality.

A frequency-dependent feedback and bias network suppresses antenna mismatch oscillations while keeping the amplifier stable and integrable.

Dual DPD correction and feedback improve drive-stage linearity, letting high-efficiency power amplifiers cut distortion without heavy power back-off.

A feedback comparator loop holds Class-D switching frequency nearly fixed, cutting EMI while keeping the audio amplifier control circuit simple.

Strictly capacitive attenuation in a DMM front end avoids parasitic RC effects, flattening frequency response while reducing noise and input loading.

Series feedback resistance and capacitance stabilize input impedance across frequency, keeping wideband gain flat without raising noise figure.

Voltage and current feedback let a switching amplifier hold rated power across changing loudspeaker impedance and frequency conditions.

An out-of-plane feedback bridge shortens RF amplifier feedback paths, reducing impedance transformation and instability with standard transistor packages.

A 3-level quantizer drives H-bridge rail switching only at defined output levels to lower audio noise and power use in portable amplifiers.

DFT-based feedback isolates a target frequency component and adjusts amplifier gain to keep its output level stable in multi-tone signals.

A feedback subtractor and filter cancel spurious signal components, improving receiver sensitivity while avoiding large high-Q passive filters.

A replica feedback loop adjusts degeneration resistance with FET switching to keep high-rate transimpedance amplifiers linear and stable.

A switched bias path lowers feedback resistance during enable, cutting amplifier settling time and guard time in radio receivers.

A tri-level, filterless PWM amplifier uses feedback integration to cut power use while preserving audio fidelity in handheld devices.

A transformer feedback path and phase compensation network keep a low noise amplifier wideband, stable, and linear at high frequencies.

Dynamic feedback and DC current adjustment let an RF amplifier preserve low noise on weak signals and resist intermodulation on strong ones.

A switch briefly couples complementary amplifier nodes to cut capacitor feedback after input transitions, boosting ADC slew rate and response.

Variable DC sources along the feedback line correct photodiode bias drift, preserving amplifier dynamic range and linearity.

A driver stage supplies charging current above the input current to speed capacitive amplifier startup while preserving bandwidth limiting and noise reduction.

Four same-direction windings on one core let class-D amplifiers switch between single-end and BTL modes while still blocking common mode noise.

A series resistor and feedback capacitor tune phase margin under varying load capacitance, improving op-amp settling without added complex stages.

A compensating feedback loop linearizes AGC-to-output power control in switcher PA modules, easing calibration and improving battery life.

A shared PWM gain path and half-period inverted differential pulses cancel equal-phase noise at the load in a class D amplifier.

A thermal sensor trims digital input gain during peak heating, protecting output switches without abrupt audio shutdown.

A segmented series and R-2R resistor network expands input range, lowers output swing needs, and reduces parasitic layout complexity.

Digital current sensing lets Class-G amplifiers reverse pull-up and pull-down drive for reactive loads, avoiding waveform discontinuities.

Selectable amplifier cells create discrete gain steps that reduce noise and distortion while preserving dynamic range and stable bandwidth.

Switchable resistors and a calibration circuit tune amplifier gain for process variations, preserving output headroom and avoiding saturation.

Phase detection and delay comparison lock class D amplifier dead-time, limiting distortion and preventing transistor overheating.

A variable threshold tied to gain control lets ALC circuits compress loud signals without clipping while preserving more natural audio dynamics.

Active bias circuitry senses and regulates Darlington pair current, avoiding resistor power loss and preserving low-voltage amplifier operation.

A feedback input-output stage cuts noise and input loading while preserving gain, linearity, and low power in compact amplifiers.

Progressive multi-stage gate driving keeps the MOSFET on until current polarity changes, cutting reverse recovery EMI and voltage overshoot.