ECS-21K-7.5A

Overview

The ECS-21K-7.5A is a monolithic crystal filter manufactured by ECS Inc. It operates at a center frequency of 21.4 MHz with a bandwidth of 7.5 kHz. The component features an impedance of 1.5 kOhms and an insertion loss of 2 dB. It utilizes a two-pole design for signal conditioning. The device is housed in an HC-49/U package, suitable for through-hole mounting. It functions within a temperature range of -20°C to 70°C.

Feature Summary

• Monolithic crystal construction for stable signal filtering
• Two-pole topology providing defined selectivity
• Through-hole mounting capability via HC-49/U package

Applications

• Intermediate frequency (IF) stages in radio receivers
• Signal conditioning circuits requiring narrowband filtering
• Communication equipment operating at 21.4 MHz

Procurement Notes

Verify the specific impedance value against the official datasheet, as some sources list 1.5 kOhms while others may reference different variants. Confirm the package type is HC-49/U and that the component is RoHS compliant. Ensure the center frequency matches the required 21.4 MHz application. Check for any ordering suffixes that might alter specifications. Cross-reference the manufacturer part number directly with ECS Inc. documentation to avoid confusion with similar models like the 7.5B variant.

Selection Notes

Select this component when a fixed 21.4 MHz center frequency is required. The 7.5 kHz bandwidth defines the passband characteristics. Consider the 1.5 kOhm impedance for circuit matching. The through-hole package dictates board layout constraints. Verify temperature range suitability for the operating environment. Compare insertion loss requirements against system sensitivity needs.

Part Context

This part belongs to the ECS Inc. monolithic crystal filter series. These components are designed for precise frequency selection in electronic circuits. The 21.4 MHz frequency is commonly used in amateur radio and specialized communication bands. The family typically offers various bandwidths and impedances to suit different circuit designs.

Replacement Considerations

The ECS-21K-7.5B shares the same center frequency and bandwidth but has an impedance of 850 Ohms instead of 1.5 kOhms. This impedance difference requires careful evaluation of circuit compatibility before substitution. Other generic 21.4 MHz filters must match the 7.5 kHz bandwidth and physical package dimensions.