CM309S-4.000MAGJTR

Crystals Overview

The CM309S-4.000MAGJTR is a surface-mount AT-cut crystal oscillator manufactured by Citizen FineDevice Co Ltd. It operates at a nominal frequency of 4 MHz with a load capacitance of 18 pF and a tolerance of ±30 ppm. The component features an equivalent series resistance (ESR) of 150 Ohms and supports a maximum drive level of 1 mW. Designed for SMD/SMT installation, it utilizes a 4-SOJ package with a 9.40 mm pitch. The unit weighs approximately 100 mg and is classified as obsolete.

Crystals Feature Summary

• AT-cut crystal construction for stable oscillation
• Surface-mount cylinder type packaging
• Designed for reflow soldering processes

Crystals Applications

• General purpose clock signal generation
• Microcontroller system timing
• Embedded device synchronization

Crystals Procurement Notes

This component is officially listed as obsolete and no longer manufactured by the producer. Availability is restricted to existing stock from third-party distributors or surplus channels. Verification of authenticity and storage history is critical due to the end-of-life status. Buyers should confirm the specific manufacturing date code and ensure compliance with RoHS requirements before procurement.

Crystals Selection Notes

Select this part only if the 4 MHz frequency and 18 pF load capacitance match the circuit design exactly. The 150 Ohm ESR requires compatible oscillator circuits capable of driving higher impedance loads. Consider alternative active oscillators or newer passive crystal families if long-term supply continuity is required, as this specific model is discontinued.

Crystals Part Context

The CM309S series represents Citizen FineDevice's line of surface-mount cylindrical crystals. This specific model belongs to the CM309S sub-category, distinguished by its 4-SOJ package format. It shares design characteristics with other members of the CMR and HCM series but offers a distinct footprint suitable for space-constrained printed circuit board layouts.

Crystals Replacement Considerations

• CM309S-4.000MAAI-UT
• CM309S-4.000MABJ-UT

Crystals FAQ

What is the package pitch dimension?

The component uses a 4-SOJ package with a lead spacing of 9.40 mm.

Is this component RoHS compliant?

Yes, the specifications indicate detailed RoHS compliance information is available in the datasheet.