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Frequency Control Devices

Frequency Control Devices are essential electronic components responsible for generating, selecting, and stabilizing specific frequencies in electronic circuits. They form the foundation of signal timing, synchronization, and filtering in modern electronic systems. Key product categories include: frequency filters, resonators and frequency discriminators.

 

Your Professional Frequency Control Devices Supplier
 

Suzhou Hangjing Elec & Tech Co., Ltd., founded in 2014, is a technology-driven small and medium-sized enterprise (SME) specializing in the full-spectrum R&D, design, production, and sales of quartz frequency control components. Rooted in a professional team and advanced manufacturing expertise, the company has developed a robust product portfolio encompassing quartz crystals, crystal oscillators, TCXO, VCXO, OCXO, crystal filters-ranging from foundational components to tailored systems.

 

 
First 123 Last
 
Why choose us

Superior Quality

A precision supply chain ensuring consistent product quality;An ultra-low failure rate validated by rigorous testing;High-quality materials and advanced technology make the product more reliable.

Service Advantages

A customer-centric service framework (covering pre-sales consultation to post-sales support) that prioritizes rapid response. 24-hour online service, timely and fast quotation for you.

Sales Market

Our Products has expanded into key international regions including Europe, Southeast Asia, the Americas, Oceania, and other major markets. This global network enables the company to provide full support to leading electronics manufacturers around the world, while maintaining a strong focus on high-quality products.

Our Certificate

All our products have passedGB/T 19001 - 2016/ISO 9001:2015 Quality Management System Standard, This demonstrates that they meet international standards for quality, safety, and performance.

 

 

微型 SMD 晶体滤波器 7050

 

Miniature SMD Crystal Filter 7050

An SMD (Surface Mount Device) crystal filter is a precision electronic component used to selectively pass or block specific frequency ranges in modern circuit design. These compact filters are widely used in telecommunications, audio systems, RF (Radio Frequency) applications, and digital signal processing to eliminate noise, suppress harmonics, and enhance signal clarity. Due to their small footprint and high reliability, SMD crystal filters are ideal for densely packed PCBs (Printed Circuit Boards) in smartphones, IoT devices, and wireless modules.

 

Frequency (MHz)

Model

No. of poles

Pass Bandwidth (KHz, min)

Stop Bandwidth (KHz, max)

Ripple (dB, max)

Insertion Loss (dB, max)

Guaranteed Attenuation (dB)

Terminating Impedance (ohms//pF)

Cc (pF)

21.400

21MQ7.5A

2

±3.75

±18

1.0

2.0

70

850/6.0

 

21MQ15A

2

±7.5

±25

0.5

1.5

70

1500/2.5

 

21MQ15B

4

±7.5

±25

1.0

3.0

70

1800/0.35

5.0

21MQ30A

2

±7.5

±50

1.5

2.0

60

2500/0

 

21.700

21.7MQ15A

2

±7.5

±28

1.0

2.0

70

1500/2.5

 

21.7MQ15B

4

±7.5

±25

1.0

3.0

70

1750/0.35

5.0

21.7MQ30A

2

±15

±50

1.5

2.0

50

2500/0

 

45.000

45MQ15A

2

±7.5

±25

1.0

2.0

70

650/3.5

 

45MQ15B

4

±7.5

±25

1.0

3.0

80

600/2.3

7.5

45MQ30A

2

±15

±60

1.0

2.0

70

1200/1.8

 

45MQ30B

4

±15

±40

1.0

3.0

70

1200/1.0

2.5

 

Features of Miniature SMD Crystal Filter 7050

 

 

High-Frequency Narrowband Filtering

This narrow-bandpass filter features a center frequency range of 21.4MHz to 45MHz (e.g., the Jingkexin CF series), a passband width of ±3.75kHz to ±15kHz, insertion loss as low as 1.0dB, and intra-band ripple ≤2.0dB.

 

High Selectivity

Leveraging the piezoelectric effect of the quartz crystal resonator, this filter achieves steep passband and stopband attenuation, guaranteeing attenuation of 18dB to over 60dB.

 

Environmental Adaptability

Compliant with RoHS and Pb-Free standards, it offers strong shock and vibration resistance (Moisture Sensitivity Level: LEVEL 1), and an operating temperature range of -40°C to +125°C (industrial grade).

 

 

 
 
Type of Miniature SMD Crystal Filter 7050
01.

Low Pass Filters

Designed to allow frequencies below a specific cutoff point to pass through while attenuating higher frequencies.

02.

High Pass Filters

These filters permit frequencies above a defined threshold to pass while blocking or reducing lower-frequency signals.

03.

Band Pass Filters

Allows only a designated frequency range (passband) to pass through, rejecting both lower and higher frequencies outside this window.

04.

Notch Filters (Band Stop)

Engineered to block a narrow range of frequencies while allowing all others to pass unaffected—ideal for eliminating specific interference sources.

 

Applications of Miniature SMD Crystal Filter 7050

 

Consumer Electronics
In smartphones, tablets, laptops, and wearable devices, SMD crystal filters ensure stable signal processing by minimizing electromagnetic interference and crosstalk between densely packed circuit components. As consumer devices support multiple wireless standards—such as Wi-Fi, Bluetooth, 4G/5G, and NFC—these filters help isolate specific frequency bands, reducing noise and improving data transmission reliability.

 

Industrial Equipment
In industrial automation, process control, and remote monitoring systems, SMD crystal filters are critical for maintaining reliable communication in harsh operating conditions. They are used in programmable logic controllers (PLCs), sensor networks, and telemetry systems that must function continuously despite exposure to temperature extremes, vibration, and electrical noise.

 

Medical Devices
SMD crystal filters play a vital role in medical electronics by enabling precise signal conditioning in diagnostic and patient monitoring equipment. In devices such as ECG machines, MRI systems, ultrasound scanners, and portable vital sign monitors, these filters separate weak biological signals from background noise and interference, which is essential for accurate diagnosis and real-time health tracking.

 

Aerospace and Defence
In aerospace and defence systems, where mission-critical operations depend on flawless communication and navigation, SMD crystal filters are indispensable. Used in avionics, satellite transponders, radar systems, and secure communication equipment, they maintain signal integrity under extreme environmental stress—including wide temperature swings, high vibration, and radiation exposure.

 

Telecommunications
SMD crystal filters are foundational in telecom infrastructure, where they are deployed in base stations, optical network units, microwave links, and core routers. By filtering out unwanted harmonics, adjacent channel interference, and spurious emissions, these components help maintain high signal clarity and spectral efficiency across cellular networks (4G LTE, 5G NR), fibre-optic systems, and satellite communications.

 

Emerging Applications
Beyond traditional sectors, SMD crystal filters are increasingly vital in cutting-edge technologies such as autonomous vehicles, smart cities, and quantum communication systems. Their ability to deliver stable, high-precision filtering supports the growing demand for reliable, low-latency wireless connectivity in interconnected environments.

 

 

How To Choose Miniature SMD Crystal Filter 7050

 

Frequency Range
The operating frequency range is the most fundamental parameter when selecting an SMD crystal filter. The filter must be designed to function efficiently within the target frequency band of your application. Crystal filters are manufactured to resonate at precise frequencies, typically ranging from a few kHz in audio and low-speed digital systems to several hundred MHz in high-frequency RF and wireless communication devices.

 

Filter Type and Application Suitability
The type of filter determines how it processes incoming signals and should be selected based on the desired signal conditioning outcome. Different filter topologies serve distinct roles in electronic systems.

 

Bandwidth and Selectivity
Bandwidth defines the range of frequencies that the filter allows to pass with minimal attenuation, typically measured between the -3 dB points. It directly impacts the filter’s ability to isolate desired signals from adjacent channels or noise sources.

 

Temperature Stability and Compensation
Temperature variations can significantly affect the resonant frequency of crystal filters due to the piezoelectric material’s inherent sensitivity to thermal changes. Ensuring temperature stability is crucial for reliable operation in environments with fluctuating conditions.

 

Insertion Loss and Signal Integrity
Insertion loss refers to the reduction in signal power that occurs when the filter is inserted into the signal path. It is typically expressed in decibels (dB) and should be minimized to preserve signal strength and system efficiency.

 

Mechanical Durability
As surface-mount components, SMD crystal filters are subjected to thermal stress during reflow soldering and mechanical stress during operation. Their physical robustness directly affects long-term reliability.

微型 SMD 晶体滤波器 7050

 

Operation and Maintenance

 

Environmental Adaptability

Temperature Range: Industrial-grade products typically support temperatures from -40°C to +125°C, but avoid thermal shock (e.g., direct exposure from -40°C to +85°C).

Humidity Control: Storage relative humidity must be ≤ 60%, otherwise oxidation of the internal electrodes may occur.

Electrostatic Discharge (ESD) Protection

Level: Most products meet HBM (Human Body Model) 2kV and CDM (Charged Device Model) 500V protection standards.

Operation: Wear an anti-static wrist strap on the production line, and the workbench ground resistance must be ≤ 1Ω.

Lifespan and Reliability

MTBF (Mean Time Between Failures): Typical value: ≥ 100,000 hours (accelerated aging test at 85°C/85% RH).

Derating: It is recommended that the operating current not exceed 80% of the rated value to extend the lifespan.

 

Certificates

 

 

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FAQ

 

Q: Whether the product can be customized logo?

A: For all the custom orders, we support custom logo.

Q: What about the delivery time?

A: For regular parts, it takes about 2-3 weeks for production, for custom orders or customized parts it may need 6-8 weeks.

Q: What is your shipping terms and shipping method?

A: We accept EXW, FOB, CFR, CIF, etc. You can choose the one which is the most convenient or cost effective for you. The shipment can be arranged by Fedex, DHL, TNT or by Air and LCL Sea shipment.

Q: How can we get samples from you?

A: Samples are available for your test. Some samples are free of charge for you ,just call contact our sales. The samples will be sent by Fedex,TNT or DHL.

Q: How can we become your distributor or sales agent in our country?

A: Welcome to be our distributor and just contact our sales for the distribution agreement and we will support you to win more orders.

We're professional frequency control devices manufacturers and suppliers in China, providing high quality customized products with low price. If you're going to wholesale discount frequency control devices, welcome to get quotation and free sample from our factory.