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…

PCB Fabricator Comparison: Signals of a Reliable Factory 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 partly visible…

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…

Ordering PCBs With Gerber Files Only: What Else Matters Gerber files describe the copper, the solder mask, the silkscreen and the outline. They are the core of a fabrication order, and they deliberately say nothing about why the board was drawn the way it was. That silence is the source…

Design for Manufacturability Review: Before Production, Not After Most of the money lost in electronics manufacturing is lost in the gap between a design that passes a functional test and a design that can be built repeatedly. That gap is what a design for manufacturability review exists to close, and…