ATS400B

Crystals Overview

The ATS400B is a 40 MHz through-hole crystal manufactured by CTS-Frequency Controls. It utilizes the HC-49/US package and operates in third overtone mode. The component features a load capacitance of 18 pF and an equivalent series resistance (ESR) of 80 Ohms. Frequency tolerance is specified at ±30 ppm, with stability rated at ±50 ppm. It supports a working temperature range of -20°C to +70°C. The unit measures 10.85mm in length, 4.50mm in width, and has a maximum installation height of 3.68mm.

Crystals Feature Summary

• Third overtone operation for precise frequency control
• Standard HC-49/US through-hole mounting configuration
• Compliant with RoHS3 environmental standards

Crystals Applications

• General purpose timing circuits
• Microcontroller clock sources
• Communication equipment oscillators

Crystals Procurement Notes

Verify that the target circuit design accommodates an 18 pF load capacitance, as this differs from similar models with 20 pF ratings. Confirm that the application environment remains within the specified -20°C to +70°C operating range to ensure frequency stability meets the ±50 ppm requirement. Check datasheet for specific soldering thermal profiles.

Crystals Selection Notes

Select the ATS400B when an 18 pF load capacitance is required for the oscillator circuit, distinguishing it from the ATS40A which uses 20 pF. Ensure the application requires third overtone operation at 40 MHz. Verify that the HC-49/US through-hole form factor fits the PCB layout constraints and that the 80 Ohm ESR is compatible with the driving circuitry.

Crystals Part Context

The ATS400B belongs to the ATS series of standard crystals from CTS-Frequency Controls. This series provides reliable frequency control solutions using quartz resonators. The ATS400B specifically addresses applications requiring 18 pF load capacitance, whereas other variants like the ATS40A offer 20 pF options within the same product family.

Crystals Replacement Considerations

ATS40A-E is listed as a direct substitute by the manufacturer. ATS400B is noted as a similar alternative. Verify load capacitance differences (18 pF vs 20 pF) when substituting.