PCB Design ServicesSchematics, Layout and Design for Manufacturing

• Companies with a new product that needs taking from schematic to production files: main controller, power and peripherals settled, then straight into prototyping.

• Clients revising an existing board: swapping components, fixing signal problems, reducing size or cost.

• Clients whose high-speed or mixed-signal boards are hard: a fast main controller, high-precision analog sensing, and routing that cannot rely on luck.

PCB design delivers not a drawing but a complete file package ready for production. The RK3128 mainboard project is the standard example: GERBER files, silkscreen, pick-and-place coordinates and stencil files, updated in step with each revision. Schematic, layout and production files all pass through the same team, with no hand-off to different people or tools in between, so versions never drift out of sync.

The hard parts of the RK3128 mainboard were high-speed signal integrity, power integrity, and managing iteration across board revisions. Layout and routing were refined over several revisions, an LCD driver board was adapted to different screens, and a debugging log recorded each revision's problems and fixes. On an SoC mainboard like this, the design centres on the power tree and timing-critical signals: if the supply is unstable or a key bus is routed badly, no amount of software tuning will recover it.

The challenge on the USB Type-C development board was replacing the Type-C MUX reliably without losing signal integrity. The work covered selecting an alternative MUX device, designing both dual-port and single-port boards, and verifying against the reference design. Type-C high-speed lanes are sensitive to the MUX, trace length and via placement, so a replacement is not done when the board powers up - it has to be verified to show no loss of performance. The project is also a direct example of component-substitution work, whether for cost-down or an out-of-stock part.

The human body posture sensor is a typical small mixed-signal board. A BLE MCU processes data from three inertial sensors - MPU6050, SC7A20 and STK8321 - a dedicated audio processor handles noise reduction and keyword spotting, a ring buffer manages real-time data, BLE connects to the phone, RFID handles identification, and a WeChat mini program provides remote control and data display. The challenge was integrating several sensors and audio processing for use in sport while keeping power low and response real-time. With digital, analog, RF and audio on one board, keeping each region from disturbing the others is the core of the layout.

High-speed design succeeds or fails on two things: power integrity and signal integrity. Can the power distribution network hold the voltage through load steps, and are the critical traces impedance-controlled, length-matched and referenced to a solid plane? The RK3128 mainboard was iterated across revisions along exactly these two lines. Honestly, a first revision of a high-speed board is rarely perfect, so multi-revision iteration and per-revision debugging logs are part of the process. We do not promise it will pass first time; we promise that every revision records what changed and why.

The core tension on a mixed-signal board is that digital switching noise couples into analog sampling and eats the sensor's effective bits. The posture sensor board is partitioned: sensor analog, audio processing, digital control and BLE RF regions each get their own placement and return paths, and sensitive analog signals never run parallel to high-speed digital lines. ADC and DAC boards follow the same rule - sampling accuracy ultimately comes down to layout, not the chip's datasheet.

PCB design is naturally a multi-revision process. The RK3128 mainboard went through several rounds of layout and routing refinement, with each revision's problems and fixes entered in a debugging log. That log pays off at hand-over: whoever receives the board knows why each jumper exists and what each revision corrected. Iterating without records just leaves the old problems for the next revision to rediscover.

PCB design is done in KiCad. We do not depend on paid EDA software, and GERBER and production files are not tied to a particular toolchain, so any fab can work from them. Whether the source files for schematic and layout are delivered, and how they are licensed, is agreed per project in the contract - this page makes no blanket commitment.

Whoever drew the board debugs its firmware. At XTELL one team writes the firmware, the app and the backend. When a peripheral misbehaves we check the schematic and put a scope on the signal to decide whether it is a layout problem or a driver problem, and change the next revision of the board if needed. The RK3128 mainboard converged quickly across revisions because design and debugging were in the same hands - across companies, every revision costs another round of emails.

Clients' products routinely need FCC or CE certification, and XTELL supports the certification work. The PCB decisions with the biggest effect on certification are made at layout: RF routing and antenna keep-out, power filtering and ground plane integrity. Thinking about certification after layout is fixed costs far more in revisions than getting it right from the start. Certificates are issued by accredited test labs; our job is to make the design pass first time.

Fabrication, assembly, DFM checks and iteration after the design is finished fall under the PCB prototyping and trial production service - this page gets the design right, that one gets the board built. The two connect without a gap: production files come out of this page's work, and trial-production problems flow back here for revision. You can engage for design only, or for design through trial production, as agreed per project in the contract.

XTELL (Shenzhen XTELL Future Technology) was founded in Shenzhen in 2016. Over the ten years since, it has delivered more than 100 projects, with clients predominantly western B2B companies. Its work covers every layer from circuit board to cloud: PCB design, FPGA, embedded firmware, Linux BSP, device interfaces, mobile apps, backends and IoT platforms.