Temperature-Induced Amplifier Zero-Point Drift | Generated by AI
C. Temperature effects on transistor parameters
In directly coupled multi-stage amplifier circuits, which pass both AC and DC signals without coupling capacitors, small changes in DC bias voltages get amplified across stages, leading to zero-point drift (unwanted output offset at zero input). While factors like power supply variations or component mismatches contribute, temperature changes primarily cause this drift. Transistor parameters such as base-emitter voltage (V_BE) and current gain (β) vary significantly with temperature—typically, V_BE drops by about 2 mV/°C—causing cumulative offsets in multi-stage setups. This makes thermal effects the dominant and hardest-to-mitigate issue.
How to Suppress Zero Drift in Direct-Coupled Amplifier Circuits
Lecture 5 - Amplifiers