AS-4.000-20 Equivalent & Substitute Parts

Part Overview

The AS-4.000-20 is a 4 MHz through-hole crystal oscillator manufactured by Raltron Electronics. This component operates at a fundamental frequency with a load capacitance of 20pF and an equivalent series resistance of 130 Ohms. The part is housed in an HC-49/US package and is classified as Active product status. Substitute parts are identified when equivalent electrical and mechanical parameters are required for circuit design flexibility, inventory management, or component availability considerations.

Substiute Parts

AS-4.000-20

Raltron ElectronicsIn Stock: 926AS-4.000-20 Datasheet

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AS-4.000-18

Raltron ElectronicsIn Stock: 1811AS-4.000-18 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the AS-4.000-20 are identified based on the following critical parameters that determine functional equivalence:

Matching Parameters (Required for Substitution):

• Frequency: 4 MHz
• Frequency Tolerance: ±30ppm
• Frequency Stability: ±50ppm
• ESR (Equivalent Series Resistance): 130 Ohms
• Operating Mode: Fundamental
• Operating Temperature Range: -20°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: HC-49/US
• Physical Dimensions: 0.447" L x 0.197" W (11.35mm x 5.00mm)
• Height - Seated (Max): 0.138" (3.50mm)
• RoHS Status: ROHS3 Compliant
• Moisture Sensitivity Level (MSL): 1 (Unlimited)
• REACH Status: REACH Unaffected

Variable Parameter (Allows Substitution):

• Load Capacitance: 18pF or 20pF

The AS-4.000-18 qualifies as a substitute part because it maintains all critical electrical and mechanical specifications while differing only in load capacitance value. This parameter variation is within the allowable range for crystal oscillator substitution in applications where the circuit design accommodates the alternative load capacitance specification.

Parameter Comparison

Engineering Selection Recommendations

Both the AS-4.000-20 and AS-4.000-18 are Active product status components manufactured by Raltron Electronics. Both parts maintain full ROHS3 compliance and REACH Unaffected status, meeting current regulatory requirements for electronic component manufacturing and use.

Selection between these parts is determined by circuit load capacitance requirements. The AS-4.000-20 operates with a 20pF load capacitance, while the AS-4.000-18 operates with an 18pF load capacitance. The circuit design must specify which load capacitance value is required for proper oscillation frequency and stability performance.

Both parts are housed in identical HC-49/US packages with matching physical dimensions and mounting characteristics, enabling direct mechanical interchangeability when electrical load capacitance requirements are satisfied.

Frequently Asked Questions (FAQ)

Q: Can the AS-4.000-18 be used as a direct replacement for the AS-4.000-20?

A: The AS-4.000-18 can be substituted for the AS-4.000-20 only when the circuit design accommodates an 18pF load capacitance specification. All other electrical and mechanical parameters are identical. The circuit schematic and design documentation must confirm that 18pF load capacitance is acceptable for the application.

Q: What is the difference between load capacitance values of 18pF and 20pF?

A: Load capacitance is the external capacitance value that the crystal oscillator circuit presents to the crystal element. Different load capacitance values affect the frequency calibration and stability characteristics of the crystal. The circuit design determines which load capacitance value is required.

Q: Are both parts physically compatible with the same PCB footprint?

A: Yes. Both the AS-4.000-20 and AS-4.000-18 are housed in HC-49/US packages with identical physical dimensions of 0.447" L x 0.197" W (11.35mm x 5.00mm) and a maximum seated height of 0.138" (3.50mm). Both parts are through-hole mounted components and are mechanically interchangeable on the same PCB layout.

Q: Do both parts meet the same regulatory compliance standards?

A: Yes. Both the AS-4.000-20 and AS-4.000-18 are ROHS3 Compliant and REACH Unaffected. Both parts carry Moisture Sensitivity Level (MSL) 1 classification, indicating unlimited shelf life without moisture control requirements.

Q: What is the operating temperature range for both parts?

A: Both the AS-4.000-20 and AS-4.000-18 operate across an identical temperature range of -20°C to 70°C. Frequency stability is maintained at ±50ppm across this entire operating range.

Q: Are there any frequency differences between the two parts?

A: No. Both parts operate at 4 MHz with identical frequency tolerance of ±30ppm and frequency stability of ±50ppm. The only difference is the load capacitance specification.