Ping Pong Buffer Design: The Handover Rules That Stop Tearing A ping pong buffer looks trivial on a block diagram: two memory banks, one being written while the other is read, and a swap at the end of every frame. In practice almost every failure in such a design happens…

Circuit Design Risks: The Ones Engineers Keep Hitting Most circuit designs do not fail because a formula was wrong. They fail because a margin was assumed rather than calculated, because two devices were expected to agree on a level that neither specified clearly, or because a part that was available…

Open Drain Signalling: How I2C Returns to High Without a Driver A logic bus where no device ever drives a high level sounds like a design error. Every participant can only pull the line low, and yet the line reliably returns to a valid high level, which is the basis…

Ground Path Inductance: Why a Common Ground Fails at High Frequency The complaint is familiar. All the grounds in the design are connected to one point, so they are at the same potential by definition, and the circuit behaves worse than a version with a continuous plane. Measurements show noise…

Reactive Load Reflection: Why the Waveform Changes Over Time A channel that behaved acceptably is modified by adding one small capacitor at the receiving end, or by changing to a larger package. The overshoot changes, a step appears in the waveform, and the settling time grows. The layout has not…

EMC Design at the Layout Stage: Fixing Problems Before the Chamber EMC failures are usually discovered in a test chamber, and they are almost always decided in the layout. By the time a product is being tested, the options are limited to adding components, wrapping tape and hoping, because the…

Design File Checks Before Release: A Pre-Delivery Checklist The most expensive mistake in electronic design is the one that leaves the desk. A footprint drawn from memory, a coordinate file regenerated before the last change, a silkscreen that hides a pin one marker: each of these costs a board respin…

Signals of a Reliable Factory in a PCB Fabricator Comparison Most quotations for the same board look similar, and the factories behind them are not. What separates a supplier that produces a predictable result from one that produces surprises is not visible in a price table, and it is only…

High Speed PCB Design Outsourcing: How to Judge a Project Team High speed projects fail in two ways. The first is technical: a design that does not meet its signal or power requirements. The second is organisational: a team that can meet them but does not have the capacity, the…

Circuit Design Partner for Production: Preparing a Requirements Brief A team that needs a circuit design partner usually already knows what the product should do. What it often lacks is a document that another company can design against, and that document is what determines whether the project runs on a…