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Vishay Intertechnology, Inc.

Vishay's "SMDY1 Series," the industry's first SMD Y1 CERAMICS CAPACITORS, delivers highly reliable EMI protection and insulation safety

Vishay Intertechnology, Inc.
Vishay Intertechnology, Inc.
  • Vishay Intertechnology, Inc.
  • NEXT Mobility
  • ICT and Industrial
  • Smart Factories and Robotics

As electronic devices such as EVs, smart meters, and industrial control equipment become increasingly densely packed, there is a demand for components that combine high reliability and safety in limited spaces. In particular, X1/Y1 class CERAMICS CAPACITORS, which provide insulation between POWER SUPPLIES lines and chassis and noise elimination, play an important role in both EMI (electromagnetic interference) countermeasures and electric shock prevention.
To meet these needs, Vishay has developed the SMDY1 series of Y1 CERAMICS disc CAPACITORS compatible with surface mount technology (SMD). While this is not the industry's first for industrial equipment, the SMDY1 Auto series for automotive applications, scheduled for mass production this year, is the industry's first.
This article explains the technical features of the SMDY1 series and explains its advantages and selection points through application examples in the automotive, industrial, and energy fields.

Technical Explanation | Differences and Roles of X1 and Y1 CAPACITORS

X1 and Y1 CAPACITORS belong to a category known as "safety CAPACITORS" designed for EMI FILTERS and safety purposes, and comply with the international standard IEC 60384-14. They are used to absorb and bypass noise and surges (overvoltage caused by lightning, etc.) that enter AC POWER SUPPLIES lines, preventing equipment malfunction and the risk of electric shock.

What is an X1 CAPACITORS?

X1 CAPACITORS are connected between the line (L) and neutral (N) of an AC POWER SUPPLIES and are used to eliminate differential mode noise. Their rated voltage is approximately 250 to 760 VAC, with a surge resistance of 2.5 to 4 kV. While the risk of electric shock is relatively low, they must be self-extinguishing to prevent fires.

What is a Y1 CAPACITORS?

Y1 CAPACITORS are connected between the line or neutral and earth (GND) to eliminate common mode noise and provide insulation protection. They have a rated voltage of 250 to 500 VAC and a surge resistance of 5 to 8 kV, and because there is a risk of electric shock, they require extremely high insulation performance and reliability.
The Y1 CAPACITORS is used in devices that require an earth connection, such as microwave ovens, televisions, and EV onboard chargers, and helps to minimize leakage current while dissipating noise.

Circuit layout example of X1, Y1 CAPACITORS

Product Overview | Features of the SMDY1 Series

Vishay's SMDY1 series is a CERAMICS disc-type EMI suppression safety CAPACITORS with an X1 rating of 760 VAC and a Y1 rating of 500 VAC / 1500 VDC. It supports capacitances up to 4700 pF and reduces board mounting area compared to conventional leaded CAPACITORS while maintaining high insulation performance and reliability.

ItemContent
Rated voltageX1: 760VAC Y1: 500VAC/1500VDC
Capacitance Range470 pF to 4700 pF (±20%)
Operating temperature range-55℃ to +125℃
Insulation resistance≥10 GΩ
Humidity resistance85°C / 85% RH / 1000 hours (Class IIB)
Implementation methodSurface mounting (reflow compatible)

The SMDY1 series is available in two sizes: C case (10 mm creep distance) and D case (14.5 mm creep distance), allowing for flexible selection according to the application.

  • C case
    W 8.6×L 14.80×T 4.0mm

  • D case
    W 14.6×L 19.2×T 4.0mm

Application circuit examples | Scenes where SMDY1 is useful

The SMDY1 series is ideal for applications that require high reliability, such as the following:

1. AC line FILTERS (EMI FILTERS)
Configuration: X1 (between L and N) + Y1 (between L and GND, N and GND)
Applications: AC ADAPTERS, SWITCHING POWER SUPPLIES, home appliances
Features: Simultaneous removal of differential mode and common mode noise, realizing stable POWER SUPPLIES supply

2. On-board charger (OBC)
*SMDY1 Auto for automotive applications will be released soon.
Configuration: Y1 is placed in the AC input section to ensure isolation from the chassis ground
Applications: OBC for EV/HEV/PHEV, e-compressor, in-vehicle AC/DC converter
Features: AEC-Q200 compliant, 85/85/1000h compatible, ideal for automotive environments

3. Solar INVERTERS
Configuration: X1/Y1 placed in AC output section
Applications: Power conditioners for solar power generation systems, hybrid INVERTERS
Features: High pressure and humidity resistance, suitable for outdoor installation

4. LED Lighting Driver
Configuration: X1/Y1 combined in the input FILTERS section
Applications: outdoor LED lighting, smart lighting, commercial lighting control
Features: SMD mounting saves space and is compatible with thin housings

5. Smart meters and IoT devices
Configuration: Y1 is placed at the AC POWER SUPPLIES input section to ensure isolation from the chassis ground
Applications: Smart electricity meters, IoT control devices, building automation
Features: Compact and highly reliable, ideal for smart devices

6. Industrial Control Devices and SMPS
Configuration: Noise FILTERS circuit combining X1/Y1
Applications: PLC, industrial AC/DC POWER SUPPLIES, motor drivers
Features: Stable operation even in high temperature and high humidity environments, effective for EMC measures

Summary

Vishay's SMDY1 series is an innovative SMD-compatible Y1 CERAMICS disc CAPACITORS that combines EMI countermeasures and insulation safety at a high level. *Although it is not the industry's first for industrial equipment, the SMDY1 Auto for automotive use is the industry's first product.
The series supports X1: 760VAC and Y1: 500VAC/1500VDC ratings, and offers stable performance even in harsh environments, including a high capacitance of up to 4700 pF, excellent humidity resistance (85°C / 85% RH / 1000 hours), and an AEC-Q200-compliant automotive-grade model.
The space-saving surface mounting and automated mounting capabilities significantly improve mountability and reliability in a wide range of applications, including EVs, smart meters, industrial equipment, lighting, and renewable energy.
In today's electronic device designs, which require high-density mounting and high reliability, the SMDY1 series is an ideal choice that combines safety and ease of mounting. Please consider introducing it as a next-generation EMI suppression component.

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