Circuit Design and Analysis
Charging and Discharging a Capacitor A capacitor is an electrical component that stores electric charge. It consists of two conducting plates separated by an insulating dielectric material. When a voltage source connects across the capacitor plates, an electric field develops across the dielectric, causing positive charge to collect on one plate and negative charge to…
Importance of Proper Drive Levels The drive level, defined as the signal power delivered to the crystal from the sustaining amplifier, is a critical parameter in crystal oscillator design. Improper drive levels can lead to degraded frequency stability, increased phase noise, clock jitter, and even oscillator failure or damage to the crystal. With modern components…
In semiconductor devices like diodes and transistors, charge carriers such as electrons and holes diffuse through the device structure. The average length that these carriers diffuse before recombining is a key parameter known as the diffusion length. When designing diode circuits like back-to-back diodes, understanding how diffusion length impacts device performance is critical. What is…
The Need for Multiple Capacitor Values Power supply decoupling is critical for ensuring stable operation of integrated circuits across a wide frequency spectrum. Using capacitors is the most common method for decoupling power rails. However, no single capacitor value provides optimal decoupling across all frequencies due to variances in capacitor impedance over frequency. Lower value…
Understanding Power Loss in Voltage Dividers A voltage divider circuit contains multiple resistors connected in series that generate an output voltage (Vout) that is a fraction of the input voltage (Vin). Power loss occurs in these circuits due to the inherent resistance (R) of the resistors. Using key terms like power (P), voltage (V), current…
Defining Capacitance and its Relation to AC and DC A capacitor is a passive electronic component that stores electrical energy in an electric field. Capacitance is a measure of a capacitor’s ability to store an electric charge for a given electric potential or voltage across its terminals. Capacitors allow alternating current (AC) signals to pass…
What is the Barkhausen Criteria? The Barkhausen criteria are a set of mathematical conditions that need to be met for a circuit to produce sustained oscillations. Specifically, for oscillations to occur in an electronic circuit, the Barkhausen criteria state that the loop gain around the amplifying device must be equal to unity and the phase…
Understanding Amplifier Instability Bipolar junction transistor (BJT) amplifiers can often suffer from instability issues that lead to undesired oscillations and noise in the output. This instability originates from the high levels of gain produced by BJT configurations coupled with the frequency-dependent feedback present in practical amplifier circuits. More specifically, the reverse transmission of signals from…
Using Voltage Level Translators What are voltage level translators and why are they needed Voltage level translators are integrated circuits designed to safely bridge signals between microcontroller circuits operating at different logic voltage levels. They function by shifting the high and low signal thresholds to match the destination device. Level translators prevent damage by eliminating…
Minimizing Heat Generation When designing high-power bipolar junction transistor (BJT) audio output stages, managing the thermal dissipation is critical to ensure reliable operation. Excessive junction temperatures can lead to thermal runaway, clipping, distortion, and potentially permanent damage to the output transistors. Various circuit optimization techniques can help minimize heat generation: Reducing Power Dissipation Through Circuit…
