AT-21 Equivalent & Substitute Parts

Part Overview

The AT-21 is a through-hole piezo buzzer transducer manufactured by PUI Audio, Inc., designed as an externally driven piezo device operating at 5kHz. This component is classified as obsolete, which necessitates identification of active equivalent parts to maintain design continuity and ensure ongoing component availability for production and repair applications.

Substiute Parts

AT-21

PUI Audio, Inc.In Stock: 772AT-21 Datasheet

Current PartRFQ

AT-2250-T-LW50-R

PUI Audio, Inc.In Stock: 1558AT-2250-T-LW50-R Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

The AT-2250-T-LW50-R qualifies as a direct substitute for the AT-21 based on the following alignment of critical parameters:

• Technology: Both components utilize piezo transducer technology
• Driver Circuitry: Both are externally driven transducers
• Frequency: Both operate at 5kHz
• Mounting Type: Both use through-hole mounting
• Termination: Both feature PC pins
• Manufacturer: Both are manufactured by PUI Audio, Inc., within the same AT series
• Product Status: The AT-2250-T-LW50-R is active, providing ongoing availability

The AT-2250-T-LW50-R provides enhanced specifications including rated voltage (15V), defined current consumption (5mA), measurable sound pressure level (92dB @ 15V, 10cm), and operating temperature range (-20°C ~ 60°C), making it suitable for applications requiring the functional characteristics of the obsolete AT-21.

Parameter Comparison

Engineering Selection Recommendations

The AT-2250-T-LW50-R is the appropriate substitute for the obsolete AT-21. Selection is justified by:

• Functional Equivalence: Both components share identical core specifications (piezo technology, external drive, 5kHz frequency, through-hole mounting, PC pin termination)
• Product Status: The AT-2250-T-LW50-R maintains active production status, ensuring supply chain continuity
• Regulatory Compliance: The AT-2250-T-LW50-R achieves ROHS3 compliance, addressing modern regulatory requirements that the non-compliant AT-21 does not meet
• Documented Specifications: The AT-2250-T-LW50-R provides complete electrical and thermal parameters, enabling precise circuit design and validation

Frequently Asked Questions (FAQ)

Q: Can the AT-2250-T-LW50-R directly replace the AT-21 in existing designs?

A: Yes. Both components share the same core functional parameters: piezo transducer technology, external drive configuration, 5kHz operating frequency, through-hole mounting, and PC pin termination. The AT-2250-T-LW50-R is designed as a direct functional equivalent within the PUI Audio AT series.

Q: What are the key differences between these parts?

A: The AT-2250-T-LW50-R provides fully specified electrical parameters (15V rated voltage, 1-30V operating range, 5mA supply current) and thermal specifications (-20°C ~ 60°C operating temperature), whereas the AT-21 specifications are not fully documented. Additionally, the AT-2250-T-LW50-R achieves ROHS3 compliance while the AT-21 is non-compliant.

Q: Are there any packaging or form factor considerations?

A: Both components use through-hole mounting with PC pin termination. The AT-2250-T-LW50-R specifies a 22mm diameter and 5mm maximum seated height. Verify these dimensions are compatible with existing PCB layouts before implementation.

Q: What is the sound output difference?

A: The AT-2250-T-LW50-R produces 92dB SPL at 15V measured at 10cm. The AT-21 SPL specification is not provided. If acoustic output is a critical design parameter, the documented 92dB specification of the AT-2250-T-LW50-R should be validated against application requirements.

Q: Is the voltage range compatible with existing circuits?

A: The AT-2250-T-LW50-R operates across 1-30V with a 15V rating. Confirm that existing drive circuits operate within this range. If the original AT-21 circuit operated outside 1-30V, circuit modification may be required.