DDZ22ASF-7 Equivalent & Substitute Parts

Part Overview

The DDZ22ASF-7 is an active Zener diode manufactured by Diodes Incorporated, rated at 20.68 V nominal with 500 mW power dissipation capability in a surface mount SOD-323F package. This component is designed for voltage regulation and protection applications requiring precise Zener voltage characteristics in compact form factors. The part is ROHS3 compliant and carries unlimited moisture sensitivity rating (MSL 1), indicating suitability for standard manufacturing environments without special handling requirements. Substitute parts are identified when equivalent electrical performance can be achieved within the specified parameter tolerances while maintaining package compatibility and regulatory compliance.

Substiute Parts

DDZ22ASF-7

Diodes IncorporatedIn Stock: 27209DDZ22ASF-7 Datasheet

Current PartRFQ

BZT52C20S-TP

Micro Commercial CoIn Stock: 6994BZT52C20S-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the DDZ22ASF-7 is determined by the following critical parameters:

Zener Voltage Compatibility: The nominal Zener voltage must fall within the application tolerance window. The DDZ22ASF-7 operates at 20.68 V with ±3% tolerance, establishing a voltage band of 20.06 V to 21.30 V. Substitute parts with nominal Zener voltages near 20 V may be considered if the combined tolerance range overlaps sufficiently with the original specification.

Power Dissipation Rating: The substitute must support the thermal requirements of the application. The DDZ22ASF-7 is rated for 500 mW maximum power dissipation. Substitutes with lower power ratings require verification that application current levels remain within the substitute's thermal limits.

Package and Mounting Compatibility: Both the main part and substitute must use surface mount technology with compatible package footprints. The DDZ22ASF-7 uses SOD-323F packaging. Substitutes using SOD-323 or SOD-323F packages maintain mechanical and electrical connection compatibility.

Impedance and Leakage Characteristics: Maximum impedance (Zzt) and reverse leakage current specifications affect circuit performance in regulation and protection applications. The DDZ22ASF-7 specifies 55 Ohms maximum impedance and 70 nA reverse leakage at 19.1 V.

Regulatory and Environmental Compliance: Both parts must maintain ROHS3 compliance and equivalent moisture sensitivity ratings to ensure manufacturing process compatibility and long-term reliability.

Parameter Comparison

Engineering Selection Recommendations

Primary Consideration - Power Dissipation: The BZT52C20S-TP substitute is rated for 200 mW maximum power dissipation, compared to 500 mW for the DDZ22ASF-7. This 60% reduction in power handling capability is the most significant parameter difference. Selection of the substitute is appropriate only when application current levels remain within the 200 mW thermal envelope at the operating Zener voltage.

Voltage Specification Alignment: The nominal Zener voltage difference of 0.68 V (20.68 V main versus 20 V substitute) is accommodated within the combined tolerance ranges. The main part tolerance of ±3% establishes a band of 20.06 V to 21.30 V. The substitute tolerance of ±6% establishes a band of 18.8 V to 21.2 V. The overlap region spans 20.06 V to 21.2 V, providing acceptable voltage compatibility for applications with moderate voltage regulation requirements.

Package Compatibility: Both parts use SOD-323 family packaging with identical footprints and mounting characteristics, ensuring direct mechanical substitution on printed circuit boards.

Regulatory Compliance: Both parts maintain ROHS3 compliance and MSL 1 (Unlimited) moisture sensitivity ratings, confirming equivalent suitability for standard manufacturing processes and storage conditions.

Impedance and Forward Voltage: Identical impedance specifications (55 Ohms maximum) and forward voltage characteristics (900 mV @ 10 mA) ensure equivalent circuit performance in regulation and protection applications within the power dissipation limits.

Frequently Asked Questions (FAQ)

Q: Can the BZT52C20S-TP directly replace the DDZ22ASF-7 in all applications?

A: Direct substitution is limited by power dissipation rating. The BZT52C20S-TP is rated for 200 mW maximum, while the DDZ22ASF-7 supports 500 mW. Substitution is valid only when application current levels remain within the 200 mW thermal envelope at the operating Zener voltage. Applications requiring the full 500 mW dissipation capability require the original part or an equivalent rated for 500 mW or higher.

Q: What is the voltage compatibility between these two parts?

A: The nominal Zener voltages differ by 0.68 V (20.68 V versus 20 V). However, the tolerance ranges overlap significantly. The main part operates within 20.06 V to 21.30 V (±3% of 20.68 V), while the substitute operates within 18.8 V to 21.2 V (±6% of 20 V). The overlap region spans 20.06 V to 21.2 V, providing acceptable voltage compatibility for applications with moderate regulation requirements. Applications requiring precise voltage regulation at 20.68 V should use the original part.

Q: Are the packages mechanically compatible?

A: Yes. Both parts use SOD-323 family surface mount packages. The DDZ22ASF-7 uses SOD-323F, and the BZT52C20S-TP uses SOD-323. Both packages share identical footprints and mounting characteristics, enabling direct board-level substitution without layout modifications.

Q: Do both parts meet the same regulatory requirements?

A: Yes. Both parts are ROHS3 compliant and carry MSL 1 (Unlimited) moisture sensitivity ratings. They are equivalent in regulatory compliance and suitable for identical manufacturing processes and storage conditions.

Q: What is the impedance difference between these parts?

A: There is no impedance difference. Both parts specify a maximum impedance (Zzt) of 55 Ohms, ensuring identical circuit performance characteristics in regulation and protection applications.

Q: How do the reverse leakage characteristics compare?

A: The reverse leakage specifications are measured under different conditions. The DDZ22ASF-7 specifies 70 nA at 19.1 V, while the BZT52C20S-TP specifies 100 nA at 14 V. Direct comparison is not possible due to different measurement voltages. Applications sensitive to leakage current should use the original part specification as the reference.

Q: What is the primary limitation of using the BZT52C20S-TP as a substitute?

A: The primary limitation is the reduced power dissipation rating of 200 mW compared to 500 mW for the original part. Applications operating at higher current levels or requiring sustained power dissipation above 200 mW must use the original DDZ22ASF-7 or an equivalent part rated for 500 mW or higher.