{"id":2501,"date":"2024-07-01T11:43:00","date_gmt":"2024-07-01T03:43:00","guid":{"rendered":"https:\/\/www.jingpengpcb.com\/?p=2501"},"modified":"2026-10-02T19:42:35","modified_gmt":"2026-10-02T11:42:35","slug":"high-precision-adc-circuit-board-layout-and-wiring-case-study","status":"publish","type":"post","link":"https:\/\/www.jingpengpcb.com\/en\/blog\/high-precision-adc-circuit-board-layout-and-wiring-case-study\/","title":{"rendered":"Case Studies on Layout and Routing of High-Precision ADC Circuit Boards"},"content":{"rendered":"

When designing high-performance data acquisition systems, engineers must carefully select components such as high-precision ADCs and the necessary analog front-end conditioning circuits. However, if the importance of PCB layout and routing is overlooked during the design process, the final performance may fall short of expectations.<\/p>\n

\"DFM<\/p>\n

This article will discuss the key considerations for PCB layout and routing when designing a high-performance ADC.<\/p>\n

In modern electronic systems, the analog-to-digital converter (ADC) is one of the key components responsible for converting analog signals into digital signals. To achieve a high-performance data acquisition system, the performance of the ADC is critical. However, the performance of an ADC depends not only on its own specifications but is also closely related to the PCB layout and routing. The following section outlines some key PCB layout and routing considerations to ensure optimal ADC performance.<\/p>\n

Key Point 1: The Importance of Reference Paths<\/h2>\n

The reference voltage of an ADC is one of the key factors affecting its performance. In traditional successive approximation register (SAR) ADC architectures, the reference voltage is sampled during each conversion; therefore, the stability of the reference voltage is critical to avoiding linear errors and missing-code errors. The path of the reference voltage is called the reference path, and it is the most critical part of the ADC layout and routing.<\/p>\n

Key Point 2: Using a Bypass Capacitor (CREF)<\/h2>\n

To provide instantaneous charging along the reference voltage path, high-quality bypass capacitors (CREF) are required. These capacitors act as charge storage devices, providing instantaneous charging during high-frequency transient currents. For optimal performance, the CREF should be placed as close as possible to the reference pin and connected to it using a short, low-inductance connection. This helps maintain low overall impedance and a constant impedance at high frequencies.<\/p>\n

Key Point 3: Separation of Analog and Digital Circuits<\/h2>\n

When laying out and routing a PCB, the board should be divided into analog and digital sections. This helps keep sensitive inputs and reference signals away from noise sources, thereby improving ADC performance. By dividing the board and arranging the layouts of the analog and digital sections appropriately, interference can be reduced and better signal integrity can be achieved.<\/p>\n

Key Point 4: Reducing Path Inductance<\/h2>\n

To minimize inductance in the reference voltage path, you should avoid placing vias between the reference pin and the bypass capacitor whenever possible. This ensures the stability of the reference signal and minimizes the impact of inductance on performance. Additionally, for ADCs that use an external reference source, you should also minimize inductance in the reference signal path.<\/p>\n

When designing high-performance data acquisition systems, PCB layout and routing are among the key factors in ensuring that the ADC performs as expected. By properly routing reference paths, using bypass capacitors, separating the analog and digital sections, and minimizing path inductance, engineers can maximize ADC performance. Therefore, special attention should be paid to these key points during the design process to ensure that the final data acquisition system delivers outstanding performance.<\/p>\n

\n

Frequently Asked Questions (FAQs)<\/h2>\n

1. Why is the reference voltage so important for an ADC?<\/h3>\n

The reference voltage of an ADC directly affects its performance, particularly its resolution and accuracy. An unstable reference voltage can cause linear errors and missing-code errors.<\/p>\n

2. Why use a bypass capacitor (CREF)?<\/h3>\n

Bypass capacitors are used to provide instantaneous charging along the reference voltage path to ensure the stability of the reference voltage. This is critical for high-performance ADCs.<\/p>\n

3. Why should the layouts of the analog and digital sections be separated?<\/h3>\n

A layout that separates the analog and digital sections helps reduce interference, improve ADC performance, and ensure signal integrity.<\/p>\n

4. Why is it necessary to reduce the path inductance?<\/h3>\n

Reducing the path inductance can improve the stability of the reference signal, minimize the impact of inductance on performance, and thereby enhance the performance of the ADC.<\/p>\n

5. How do you determine the appropriate value and type of a bypass capacitor?<\/h3>\n

The value and type of the bypass capacitor should be selected based on the ADC's requirements and the specific design conditions; simulation and testing are typically required to determine the optimal choice.<\/p>","protected":false},"excerpt":{"rendered":"

\u5728\u8bbe\u8ba1\u9ad8\u6027\u80fd\u6570\u636e\u91c7\u96c6\u7cfb\u7edf\u65f6\uff0c\u5de5\u7a0b\u5e08\u9700\u8981\u7cbe\u5fc3\u9009\u62e9\u9ad8\u7cbe\u5ea6ADC\u4ee5\u53ca\u6240\u9700\u7684\u6a21\u62df\u524d\u7aef\u8c03\u8282\u7535\u8def\u7b49\u7ec4\u4ef6\u3002\u4f46\u5728\u8bbe\u8ba1\u7684\u8fc7\u7a0b\u4e2d\uff0c […]<\/p>\n","protected":false},"author":1,"featured_media":8865,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"slim_seo":{"title":"Case Studies on Layout and Routing of High-Precision ADC Circuit Boards","description":"How should a PCB for a high-precision ADC be laid out? This article explains four key factors that affect sampling accuracy, ranging from the reference voltage path, the CREF bypass capacitor, analog-to-digital isolation, to loop inductance control."},"_slim_seo_primary_term_category":0,"_slim_seo_primary_term_post_tag":0,"footnotes":""},"categories":[26],"tags":[286],"class_list":["post-2501","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","tag-286"],"_links":{"self":[{"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/posts\/2501","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/comments?post=2501"}],"version-history":[{"count":1,"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/posts\/2501\/revisions"}],"predecessor-version":[{"id":19260,"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/posts\/2501\/revisions\/19260"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/media\/8865"}],"wp:attachment":[{"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/media?parent=2501"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/categories?post=2501"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.jingpengpcb.com\/en\/wp-json\/wp\/v2\/tags?post=2501"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}