Circuit Design

Voltage regulator protection circuit for reverse polarity, ESD, over-voltage, and noise What it does This circuit protects a voltage regulator against reverse polarity, electrostatic discharge (ESD), over-voltage conditions, and noise. Why it matters Circuit designers must consider both nominal and fault conditions when designing circuitry to ensure robust and reliable performance. Fault conditions for voltage regulator circuits include: Reverse polarity on VIN Positive ESD e

What it does Diodes clamp harmful inductive spikes when relays de-energize, protecting surrounding circuitry. How it works When relays de-energize, their coil (an inductive element) causes large voltage spikes at the relay-MOSFET junction. Diodes are used clamp this voltage spike to a safe level so it does not exceed the drain-source voltage rating (VDS) of the MOSFET, potentially damaging the device. Here's how it works. De-energized (initial state). When no voltage is prese

I recently designed a circuit using an ATtiny84A and found it difficult to locate information from Microchip Technology regarding connector pinouts, wiring diagrams, and connector part numbers for In-System Programming (ISP) via the Serial Peripheral Interface (SPI) using an Atmel-ICE programmer. This article presents a working circuit, design description, and bill of materials (BOM) for others to reference when creating their own ATtiny84A-based circuits to save time and gua

What it does This circuit converts a noisy switch input signal to a clean, debounced logic signal. How it works Assume the circuit has reached steady state, with C1 fully charged and TP1 at 0 volts. When S1 closes, its contacts momentarily bounce (before fully closing) causing paths A and B to alternatively charge and discharge capacitor C1 during the bounce period. Since R2 is much larger than R1, path A takes longer to charge C1 than it takes path B to discharge C1, essenti

General Instructions Use this parametric design guide to create a functional, and safe, resistor-capacitor (RC) snubber circuit for use with 120 VAC 60 Hz single-phase motors that are controlled by an upstream switching device. Who should use this design guide This design guide is meant for hobbyists, circuit designers, and engineers who are designing an RC snubber from scratch or analyzing an existing design. Use-case and circuit topology Use this design guide for RC snubber