Circuit Design and Analysis
What is a Capacitor? A capacitor is an electronic component that stores electric charge. It consists of two conductors separated by an insulator known as a dielectric. When voltage is applied across the conductors, electric fields develop across the dielectric, causing positive charge to collect on one conductor and negative charge on the other. Key…
Purpose of Pull-up Resistors in Digital Circuits Pull-up resistors serve the key function of establishing a defined voltage level for input signals to digital logic gates and microcontroller pins when external circuit drivers are in a high-impedance state. They pull the voltage of floating signal lines up from an unstable middle-level state to a reliable…
Why Capacitors Behave Counterintuitively Capacitors demonstrate various behaviors that seem to defy intuition. For example, the relationship between a capacitor’s voltage and its stored electric charge does not follow a linear trend. Instead, as more charge accumulates on the plates of a discharged capacitor, the voltage increases exponentially towards the supply level. Additionally, though current…
Choosing the Right I2C Pull-up Resistor Values The inter-integrated circuit (I2C) protocol relies on pull-up resistors connected to the serial data (SDA) and serial clock (SCL) lines to maintain the bus voltage levels. Weak pull-up resistors can cause issues with slow rise times, noise susceptibility, and clock stretching that disrupt I2C communication. Choosing appropriate resistor…
Why Decoupling Capacitors are Critical Decoupling capacitors perform several vital functions in electronic circuits. Firstly, they prevent noise and fluctuations on power supply lines that provide current to integrated circuits (ICs) and other components. The decoupling capacitors act as a local energy storage reservoir, supplying transient currents when needed while also filtering high frequency noise…
Defining Class AB Amplification Class AB amplification refers to amplifier circuits designed to operate in the region between pure class A and pure class B operation. In contrast to class A amplifiers that conduct during the entire waveform cycle, or class B amplifiers that conduct for half the waveform cycle, class AB amplifiers conduct for…
Preventing Damage from Back-EMF Inductive loads like relays and solenoids generate back electromotive force (back-EMF) when switched off. This back-EMF can produce high voltage spikes that can damage microcontroller input pins. To prevent this, clamping diodes are used to shunt the back-EMF to the power supply rails. The clamping diodes conduct when the spike exceeds…
Parasitic inductance is the unwanted inductance that exists in all electronic components and PCB traces. This inductance works against the decoupling capacitors, causing impedance peaks that lead to power supply noise. Minimizing this parasitic inductance is critical for ensuring clean power delivery to integrated circuits. Excessive parasitic inductance causes problems like signal integrity issues, increased…
Common LED Drive Circuit Pitfalls Designing robust and reliable LED drive circuits requires attention to detail in order to avoid common pitfalls. Improperly designed circuits can lead to issues like thermal runaway, flicker, dropouts, and startup failures which degrade performance and reliability over time. By carefully considering component selection, thermal management, feedback control, power supply…
Selecting the Right Voltage Regulator Voltage regulators are integral components in power supply circuits that provide stable voltage rails to power sensitive analog and digital integrated circuits. Choosing the right voltage regulator ensures the regulator can provide the required current, maintains voltage regulation in the face of input voltage fluctuations and load changes, and avoids…
