Wave Soldering Process Guide for Through Hole Boards Wave soldering remains the standard way to attach through hole components at volume, and the process has changed less than the surface mount line beside it. What decides the result is still the flux, the preheat, the wave and the way the…

LDO or Switching Regulator: Choosing for Noise and Efficiency The choice between a linear regulator and a switching regulator is usually presented as efficiency against noise. The real decision involves the drop out, the thermal path and where in the chain the conversion happens. The Fundamental Difference A linear regulator…

Buzzer Driver Circuit Design Guide A buzzer is a small load that is easy to drive badly. The two common types behave quite differently, one draws a current pulse with a large inductive kick and the other looks like a capacitor, and using the wrong drive circuit produces a quiet…

Flyback Converter Design: Feedback, Creepage and Layout An isolated supply breaks the ground connection between the input and the output, which allows a measurement to be made across a potential difference and allows a circuit to be referenced to a point that is not ground. What the Isolation Provides The…

E-Paper Display Driver Circuit Design An e-paper display holds its image without power, which makes it ideal for a battery powered label or a status panel. The trade is that the image is written with a high voltage waveform applied for a defined period, so the driver circuit is a…

Input Protection: Reverse Polarity, Surge and Overvoltage Anything connected to a product by a user is a potential source of damage to it. Input protection is the set of parts that stand between the outside world and the circuit, and it is frequently the set of parts that receives the…

Resin Plugging and Via in Pad: Process and Risks When a ball grid array is dense enough that the escapes cannot fit between the pads, the via has to move into the pad. That decision fixes the routing but changes the fabrication process, because an open hole under a solder…

Double Sided Aluminium Core Board Structure And Use An aluminium core board replaces the usual insulating laminate with a metal base, and a double sided version sandwiches that base between two copper layers. The arrangement solves a specific problem. Circuits that carry significant current generate heat that has to leave…

PCB Solder Mask Color: Meaning and Limits A green board, a blue board and a black board are the same board. The colour is the solder mask ink printed over the copper, and although the choice has real consequences for inspection and repair, it has almost none for the electrical…

Trace Width and Current: Sizing for Temperature Rise A trace carrying current dissipates heat, and the heat leaves through the laminate and the air. The temperature rise that results is the quantity that sets the trace width, and it depends on the environment as much as on the current. What…