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Frequently Asked Questions



About our Company



Ceramic Capacitors



High Frequency Devices



Inductors



Low Temperature Cofired Ceramics (LTCC)



Multilayer Devices



Resistive/Thermistors



Resonators






About our Company

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Can I purchase product or request samples directly from the website?
Murata Americas does not offer the ability to request samples or purchase products directly from our website at this time. Our sales channel network of authorized Distributors and Sales Representatives can assist with either of these requests as well as obtaining quotations and checking product inventory.

Does Murata Americas or Murata Mfg. Co. manufacture fax machines?
No... All Murata Fax machines are made by Muratec. Muratec originally chose the same name as Murata only to change to their current name at a later date. Our company is the original Murata, a worldwide manufacturer of discrete components and semiconductor devices. Even though Muratec has since changed their name, it was not before a number of fax machines had been distributed in the marketplace under the name Murata. The Muratec link is www.muratec.com.

Does Murata show every part number they make in their catalogs or on the web page?
No... Murata (and other suppliers) have various stages of product development and design reviews prior to releasing a product to mass production. Also, many products (such as microwave filters, VCO's, Sensors, etc...) are very custom in nature to meet specific needs of the customers' design. For these reasons, it is not always possible or practical to show all possible part numbers in catalogs or on our web page.

Here is a general rule to follow when you cannot find an exact product or part number in one of our catalogs or on our web page. If your specification and need is similar to an existing part number or product offered by Murata, then define your need to one of Murata's authorized Distributors or Sales Representatives, or send us your technical question. It is always best to refer to one of our existing products or specifications and then show the different specification you require and ask us to review and consider if we can supply to meet your need. Often, you might be surprised to find that we already have an existing part number or near future planned release of a newly created design that could meet your needs. If not, we will then consider the potential for us to design a new product to meet your need. If we cannot meet your need, then we will tell you clearly the best or closest option in our product portfolio for you to consider.

How do I find out about employment opportunities at Murata?
Murata Americas posts specific positions available within our company in our Employment Opportunities section

When did Murata start using Global Part Numbers?
The New Global Part Numbers went into effect June, 2001.


Ceramic Capacitors

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How are EIA temperature codes defined and what do they mean?
EIA (Electronic Industry Alliance) has established a 3-character code which describe the capacitance versus temperature performance for capacitors. For high dielectric constant types (EIA Class II and III), the first two digits designate the operating temperature range. The third digit designates the capacitance change over the operating temperature range. The following describes the coding system used:
EIA Temperature Codes

What is a X capacitor?
This is used to define safety approved capacitors where failure in the circuit will not lead to electrical shock. For example, a capacitor connected between the AC power lines to reduce normal mode noise in a circuit. (UL and CSA refer to this application as "Across-the-line noise").
X Capacitor

What is a Y capacitor?
This is used to describe safety approved capacitors whose failure in a circuit will present danger of electrical shock. For example, a capacitor connected between the AC power line and the ground conductor in a circuit to reduce common mode noise. (UL and CSA refer to this a "Line-by-pass noise"). The capacitance is limited up to 4700pF so leakage current can be controlled.

Y Capacitor


High Frequency Devices

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How does Murata specify Insertion Loss and Ripple for their high frequency dielectric filters?
For many of Murata's high frequency filters, be it ceramic block, SAW, or multilayer ceramic, Murata specifies I.L. over the specified pass band relative to 0dB reference level. This differs from many engineer's description of I.L. which is typically thought of as being the minimum loss point in the filter's response curve. Murata's specified maximum I.L. typically occurs at the end of the specified pass band width. Murata then specifies ripple as the difference between the maximum and minimum I.L. points. An example of this I.L. and ripple can be seen in the following graph which shows an 836 MHz center frequency filter that has a pass band range of 824 to 849 MHz.

Insertion Loss and Ripple

What VCO frequencies are available?
Please refer to the Murata PDF Catalog Library or look in our products section. If you cannot locate the required frequencies, please submit a technical question to our Engineering Help Desk with the desired size, center frequency, specific application, and estimated annual usage.

Will Murata consider custom design requests for SAW filters?
Due to the overwhelming demand for Murata SAW devices, Murata is concentrating its design efforts to filters used in the major wireless markets such as digital cellular, etc. However, if you have an opportunity that would exceed an annual use of more than 100,000 pieces in an emerging or established application, please provide your detail requirements to a Murata representative or authorized distributor. Your request, and the market it applies to, will be reviewed by Murata and a decision made as to whether we already have a similar design to meet your needs or a custom design can be developed.


Inductors

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What are the EIA case sizes offered by Murata for surface mount inductors?
The Electronic Industry Association (EIA) has established case size standards for chip inductors within the market. Murata offers many of the different case sizes for varying applications. The following shows the conversion from the EIA standard to the Murata product series: (Please reference Global PN notice / meaning below)

EIA Case Sizes

In an effort to unify and shorten part numbers on a global basis, Murata Electronics has implemented a new part numbering system (Global Part Number or GPN). While Murata is changing the part numbers, the performance and specifications of the components will remain the same. The global unification project began in June 2001. Since there are several hundreds of thousands of part numbers on hand, this new system requires a great deal of preparatory work and coordination with Murata's overseas facilities. Please keep in mind that not all Murata’s customers have converted to the new Global Part Number. Until everyone converts to the Global Part Numbering system please reference previous part number structure as well as Global Part Numbering structure.

What are the three manufacturing technologies of Chip Inductors.
Murata has three technologies of manufacturing chip inductors: Monolithic, Thin Film, and Wire Wound. The reason for offering three technologies is design flexibility. Each construction technology has unique features that provide a wide range of characteristics suitable for various applications.

Monolithic Inductors consist of an integrated multilayered process that is available with a ferrite or ceramic structure. The ferrite structure is suited for lower frequency applications and the ceramic structure is designed to meet the demands of higher frequency circuits. Both structures are available in small case sizes and are cost effective.

Thin Film inductors are manufactured using a photolithography process on a ceramic / glass substrate, which produces a highly accurate coil pattern. The process achieves tight tolerance, compact size, and minimizes stray capacitance making these inductors ideal for high frequency circuits.

Wire Wound inductors consist of copper wire wound on a ferrite or alumina bobbin. As with the monolithic structure, the ferrite bobbin is suited for lower frequency applications, while the alumina is suited for high frequency applications. As this technology utilizes an actual wire for winding, the Q value is high and the DC resistance is lower enabling higher rated current.

Manufacturing Technologies of Chip Inductors


Low Temperature Cofired Ceramics (LTCC)

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What is LTCC?
A multilayer ceramic material and process that allows the cofiring of multiple substrate layers with printed thick film electrodes at temperatures of approximately 1000 Deg. C. This process combined with qualified design proficiency is utilized to create several innovative products. These products are a result of LTCC's ability to provide tight tolerance geometry and pattern manipulation to yield high levels of passive component integration and highly integrated module designs.

Some Murata LTCC Product Examples introduced over past 10 years:
-LC Filters
-Baluns
-Couplers
-Chip Antenna
-RF Diode Switches
-Highly Integrated Module (RF&Microwave Receive / Transmit Modules)

The Basic Process:

Low Temperature Cofired Ceramic (LTCC)


Multilayer Devices

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What is a delayline?
A delayline provides a constant time differential without distortion between the input and the output of the device.
The time difference between In-put signal and Out-put signal is the delay time.

Delayline

Computer and digital signal designers need to control the timing of signals between processing points. Delay lines provide adjustment to signal speeds by creating a delay between two points on the circuit board.

Delayline Functions:
-Signal propagation with delay time
-Temporary memory of Pulse and Analog signal
-Temporary accumulation of energy
-Conversion and Coding of signal wave-form

Murata provides an electromagnetic and passive delayline. Murata LDH series delay gets long delay time and matches up uses at high frequency in the small SMD package by utilizing our advanced ceramic and multilayer design technologies.

Application of delayline - Equipment that utilize delay lines:
-Computer ( PC, Server, Work Station )
-Game machine
-Factory Automation machine ( Touch Panel, Controller )
-Plain Paper Copier ( Digital machine )
-Digital Camera
-Video Camera
-LCD ( Driving circuit )
-Laser Printer
-Car navigation
-Collision prevention radar
-Wireless LAN
-Fiber Optics
-Microwave communication machine
-Wireless Base Station ( Cellular, Disaster prevention wireless )
-Telephone Switch / Exchanger
-Measuring Equipment ( Oscilloscope, Synthesizer, IC tester )
-Data storage
-Broadcasting Machine ( Camera, VTR, Optical disc )
-Medical Machine


What is an LC filter?
An LC filter is just that...a filter made up of a combination of L's (inductance) and C's (capacitance). By changing the combination, number, and value of L's and C's, several different types of devices can be made. Just in the filter family, LC filters can take several forms. Among these are bandpass filters (BPF), low pass filters (LPF), high pass filters (HPF), and traps. These filters can even be packaged in the same chip to make components such as diplexers (LPF and HPF) and dual filters. Generally, LC filters are less costly and have good design flexibility as compared to other filtering technologies.

What is the difference between your current antenna technologies?
There are three major types of chip antennas offered by Murata. The first is a multilayer chip antenna with P/N starting "LDA". Basically, this is a linearly-polarized, helical antenna manufactured by multilayer processes. Another type of chip antenna offered by Murata is the dielectric antenna with P/N starting "ANC". This type is a linearly-polarized, patch type antenna that is manufactured by printing an antenna pattern on a ceramic block. These can be single or dual resonant antennas. A subset of that family is the GPS patch antenna that is circularly polarized for use in GPS (satellite) application, also starting "ANC". Within these families, there are many variations resulting in a wide variety of antenna solutions.


Resistive/Thermistors

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What is a carbon resistive element?
Many of Murata potentiometer series use carbon as the element of choice. This type of element uses either carbon black or graphite as it's major resistive materials. It is combined with phenol resin, etc, via a binder, to form a resistive element. This type of element produces one of the least expensive resistor and has been used in industry the longest.

What is a cermet resistive element?
This type of potentiometer uses a metallic oxide as the major resistive material and is combined with a glassy binder. This combination forms a resistive element that has a large load capacitance with little drift producing a highly reliable resistor over a wide temperature range.

What is the meaning of temperature coefficient (TC) of resistance (ppm/C)?
It is a rate of change of the resistance value expressed in units of parts per million (ppm) when the temperature increases by 1C to a reference temperature. It is generally used as a gauge to show the temperature stability of a resistive element (i.e.: cermet is inherently more stable than carbon elements). It is expressed by the following formula:

Temperature coefficient of resistance (TC) = (R2-R1) / (R1*(t2-t1)) X 106 (ppm/C)

Where:
t1 : Reference temperature expressed by C.
t2 : Test temperature expressed by C.
R1 : Resistance value at the reference temperature expressed in ohms.
R2 : Resistance value at the test temperature expressed in ohms.


Resonators

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Are the CST and CSTCC series resonators polarized?
Theoretically, CST and CSTCC resonators are basically the same regardless of direction. In practice, this is not exactly the case. Murata does show the CST and CSTCC resonators with polarity for the following two reasons: (1) in mass production of the ceramic resonator, the resonator is only sorted in one polarity direction per specification. (2) the two internal load capacitors ( of a given part sample ) are typically not the exact same value (spec tolerance on value id +/-20% in most cases ). Assuming the two internal load caps are of slight different value within tolerance, it is possible for the oscillation frequency to be slightly different depending on which way the resonator is oriented in the circuit. Due to this, using the ceramic resonator in the opposite polarity (as indicated in the part specification) has some chance for the resulting initial oscillation frequency not being within specification.

How do I insure a Murata ceramic resonator will work with an IC I am using for my design?
To ensure stable oscillation between the resonator and the IC, Murata recommends that customers take advantage of the free IC Characterization process. With the differences in clock circuits built into microcontrollers and the variation of ceramic resonators, clock circuit design can be very time consuming. Murata's proven characterization service takes this burden off design engineers, allowing them to focus on other key items of their design. This service is free of charge.

To check to see if Murata has characterized a particular IC in the past, check our "CERALOCK" vs. IC parts search. If you have additional questions, contact your local authorized Distributors or Sales Representatives.

What is a resonator?
A resonator is a passive device that is used with the clock circuit of an IC to set the speed of the IC. The resonator by itself is not a clock, so it must be used with circuitry built into the IC to create the clock signal. Quartz crystals have been used in this manner for many years, but Murata offers lower cost and more rugged ceramic resonators. The clock circuit consists of the passive resonator, quartz or ceramic, and an active amplifier that is built into the IC.

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