SEIKO EPSON CORPORATION Crystal Unit – MHz Range

Category: Crystals Resonators, Electronics, Seiko Epson Corporation

Overview

The datasheet provided outlines the specifications for Seiko Epson Corporation’s range of MHz crystal units designed for precise frequency control applications. The products encompassed by the datasheet include the FA-238V, FA-238, and TSX-3225 models, which are RoHS-compliant, lead (Pb)-free components suitable for various applications in electronics, such as mobile phones, Bluetooth devices, WLAN ISM band radios, and clocks for microprocessor units (MPUs).

Product Specifications

The crystal units operate in the nominal frequency range of 12 MHz to 50 MHz for the FA-238 and FA-238V models and up to 48 MHz for the TSX-3225. The units have a compact form factor with external dimensions of 3.2 x 2.5 x 0.6 mm for the FA-238 and FA-238V, and 3.2 x 2.5 x 0.7 mm for the TSX-3225. They are designed to function in fundamental overtone order. For specific requirements, customers are encouraged to get in touch with the manufacturer.

Environmental and Mechanical Characteristics

The units can be stored in temperatures ranging from -40°C to +125°C, and operate at temperatures between -40°C and +85°C with a standard drive level of 0.1 µW. For configurations outside the listed specifications, the datasheet suggests consulting the manufacturer. Frequency tolerance is offered at ±10 ppm at +25°C, with frequency stability over temperature (frequency versus temperature characteristics) rated at +30 x 10^-6 to -20 x 10^-6 from -20°C to +70°C or +75°C, depending on the model.

Electrical Characteristics

The recommended load capacitance is 7 pF to 15 pF. The units exhibit frequency aging at a maximum of ±10^-6 per year, with specific aging rates provided for various frequency ranges. To ensure precise functionality, motional resistance, or equivalent series resistance (ESR), varies with frequency and is detailed in a table format for different models and frequencies within the datasheet. Typical ESR values range from 40 ohms to 100 ohms.

Additional Technical Data

The datasheet also includes details about the product name and standard form, illustrating how the part number indicates model, operating frequency, load capacitance, and frequency tolerance. Visual aids such as the internal connection diagram (top view) and the recommended footprint for PCB layout are provided for proper integration into electronic devices.

Design and Application Guidelines

System designers are advised to specify frequency temperature characteristics and the desired operating temperature range when making inquiries. The datasheet concludes with a visual representation of external dimensions, as well as a note on the internal connection where pins #2 and #4 are connected to the cover and should be grounded.