The ECS-120-20-30B-DU is a miniature SMD crystal oscillator housed in a compact 5.0 × 3.2 × 0.85 mm ceramic package, designed for communication and test equipment applications. It operates in fundamental mode with a frequency range of 10.000 to 50.000 MHz, offering frequency tolerance of ±30 ppm at +25°C and frequency stability of ±100 ppm across the operating temperature range of -55 to +125°C. The device features a shunt capacitance of 5 pF maximum, load capacitance of 8–20 pF (series), and a maximum drive level of 300 µW, with ESR values ranging from 30 to 80 O depending on frequency. The RoHS-compliant, lead-free design with a 5 × 3.2 mm footprint makes it ideal for compact, high-reliability applications in communication systems, test equipment, and other frequency-critical circuits requiring stable oscillation over a wide temperature range.