FAQ
Frequently Asked Questions
What certifications does VOOHU Electronics have?
VOOHU Electronics holds ISO9001:2015 international quality system certification, ISO 14001:2015 environmental certification, RoHS environmental certification, REACH certification and CE certification.
How can I quickly find the right product for my project?
On the VOOHU official websiteYou can quickly select online through product classification or parameter filtering (such as speed, packaging, operating temperature, current, etc.); you can also visit "Solutions" page to view recommended solutions that match your needs. If you need further support, you can contact the technical support team directly and provide application scenarios, and we will accurately recommend the best solution for you.
What are the advantages and limitations of capacitive ChipLAN?
Capacitive ChipLAN (capacitive chip network transformer) uses high-precision coupling capacitors to replace traditional magnetic ring coils to achieve signal isolation and impedance matching.
1. Core advantages: small size (can reach 1.6×0.8mm), supports ultra-high speed (10Gbps+), lower cost and does not require magnetic materials.
2. Limitations: Only transmitting AC signals results in limited DC balanced encoding, poor low-frequency response (usually >100kHz), weaker common-mode rejection ratio and surge protection capabilities than traditional transformers, and is sensitive to ESD.
3. Applicable scenarios: consumer electronics with extremely limited space (such as ultra-thin notebooks, mobile phone docking stations), high-speed short-distance interconnection (server backplanes, optical modules) and cost-sensitive IoT devices; not suitable for industrial sites, PoE power supply or long-distance outdoor scenarios that require strong isolation and anti-interference.
1. Core advantages: small size (can reach 1.6×0.8mm), supports ultra-high speed (10Gbps+), lower cost and does not require magnetic materials.
2. Limitations: Only transmitting AC signals results in limited DC balanced encoding, poor low-frequency response (usually >100kHz), weaker common-mode rejection ratio and surge protection capabilities than traditional transformers, and is sensitive to ESD.
3. Applicable scenarios: consumer electronics with extremely limited space (such as ultra-thin notebooks, mobile phone docking stations), high-speed short-distance interconnection (server backplanes, optical modules) and cost-sensitive IoT devices; not suitable for industrial sites, PoE power supply or long-distance outdoor scenarios that require strong isolation and anti-interference.
What is the difference between CHIP LAN and traditional transformers?
Capacitive ChipLAN uses capacitive coupling to achieve Ethernet isolation. Compared with the magnetic coupling solution of traditional magnetic transformers, the core difference is that the former transmits AC signals through high-voltage capacitors and has higher integration (can be implemented on a single chip), lower packaging height, better high-frequency characteristics and resistance to magnetic field interference, but cannot transmit DC (so it does not support PoE power supply); while the latter relies on inductive magnetic core coupling, which is larger and easily saturated due to the influence of magnetic fields, but it can simultaneously isolate DC power and is naturally compatible with PoE.
What should we pay attention to in the typical circuit design of capacitive ChipLAN?
① DC blocking capacitors (usually 0.1μF) are connected in series to the input and output to prevent DC bias from affecting the coupling accuracy; ② The signal line must be strictly controlled with 100Ω differential impedance, and the trace should be as short as possible and refer to the complete ground plane; ③ Add it on the side of ChipLAN close to the PHY Add a common mode choke to make up for its lack of CMRR; ④ Add ESD protection diodes (such as TLP series), because ChipLAN's own anti-static ability is weak; ⑤ Avoid use in situations where the isolation voltage exceeds 500V, otherwise there is a risk of breakdown.
Why is it recommended to add a common mode choke next to Chip LAN?
Capacitive Chip LAN has a weak common mode rejection ratio CMRR and poor resistance to common mode interference. Adding a common mode choke can make up for the EMC shortcomings, suppress common mode noise, and improve electrostatic and radiation immunity.
