Cover story
Rethinking programming/debug/ test connections for MCUs
T
here’s nothing particularly new about serial communication. Engineers have been using serial interfaces for decades, and they remain one of the simplest and most useful ways of communicating with an embedded system. What has changed, however, is the size of the target hardware. Processors have become smaller, boards have become denser and PCB real estate has become more valuable. Yet, many debug interfaces are still built around relatively large connectors and long cables that were designed years ago, when board space was less constrained. On today’s compact and often thin designs, the connector can be one of the largest and most awkward parts of the system. In addition, traditional USB-to-serial cables place the interface electronics at the host end of a relatively long instrumentation cable. While this approach has worked well for many years,
it brings clear compromises, especially when working with compact, densely populated designs. Neil Sherman, President of Tag-Connect, saw the problem as one of physical implementation rather than the serial interface itself. If the electronics could be moved closer to the target, the long instrumentation cable would no longer be a limiting factor. It was this thinking that led to the development of the
new Chip-in-Connector family by Tag-Connect, which utilises a USB-C adapter and conversion electronics inside the connector itself. A shortened signal path improves signal integrity and also allows for the use of a standard USB data cable, which is considerably less bulky.
“The main advantage to be gained with Chip-in-
Connectors is in getting the low-voltage, high-speed signals closer to the target without using a long, unshielded wire,” said Sherman. Bringing this idea to life proved more challenging than
expected. “It’s pretty hard to put electronics in a small connector,”
he explained. The challenge went beyond circuit design. Electronics had to fit inside an enclosure only slightly larger than the connector itself and also survive the overmoulding process. High pressure, thermal management, mechanical stresses and material selection all became equally important. “When we first tried to overmould our wires, we made expensive mould tooling and it just blew the wires inside
06 July/August 2026
www.electronicsworld.co.uk
our connectors apart,” recalls Sherman. “Maybe two or three wires out of six or ten remained. The other connections literally were blasted apart.” For a company whose expertise has long centred on moulding fine wires and connector assemblies, solving those manufacturing problems became a natural extension of existing processes. “Encapsulating thin wires is our business. We know how
to do that,” said Sherman. Even component selection became a packaging
exercise. Fitting the required circuitry into such a small volume demanded extremely small passive components and careful PCB layout. Features that might appear straightforward, such as indicator LEDs, required dedicated tooling to ensure they remained visible after overmoulding.
Figure 1: Chip-in- Connector TC2030- CIC-FTH232H “Noel” 5V variant. Each variant features a different Tag-Connect team member
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