PZM22NB,115 Equivalent & Substitute Parts

Part Overview

The PZM22NB,115 is a 22 V Zener diode rated at 300 mW for surface mount applications in the SMT3/SOT-23-3 package. Manufactured by NXP USA Inc., this component is classified as obsolete, necessitating identification of active equivalent parts for new designs and ongoing production requirements. Substitute parts must maintain electrical compatibility across voltage regulation, power dissipation, and thermal operating ranges while conforming to the same mechanical package specifications.

Substiute Parts

PZM22NB,115

NXP USA Inc.In Stock: 1121PZM22NB,115 Datasheet

Current PartRFQ

CZRT5251B-G

Comchip TechnologyIn Stock: 1106CZRT5251B-G Datasheet

DirectRFQ

BZX84-C22,215

Nexperia USA Inc.In Stock: 2578BZX84-C22,215 Datasheet

MFR RecommendedRFQ

BZX84C22-7-F

Diodes IncorporatedIn Stock: 35386BZX84C22-7-F Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the PZM22NB,115 is determined by strict alignment of the following electrical and mechanical parameters:

Primary Substitution Criteria:

• Zener voltage: 22 V nominal
• Tolerance: ±5% or tighter
• Power rating: 300 mW minimum
• Package: TO-236-3, SC-59, or SOT-23-3 (mechanically and electrically equivalent)
• Operating temperature range: -65°C to 150°C minimum
• Surface mount configuration

Secondary Compatibility Factors:

• Impedance (Zzt): Maximum 25 Ohms (main part specification)
• Reverse leakage current: 70 nA @ 17 V (main part specification)
• Forward voltage: 1.1 V @ 100 mA (main part specification)
• RoHS3 compliance and MSL Level 1 rating

Substitute parts are grouped based on whether they meet all primary criteria. Variations in secondary parameters (impedance, leakage, forward voltage) are documented but do not disqualify substitution when primary criteria are satisfied and the part remains functionally compatible within the application circuit.

Parameter Comparison

Engineering Selection Recommendations

CZRT5251B-G (Comchip Technology) — Active Status, Direct Electrical Match

This substitute maintains the 22 V nominal voltage, ±5% tolerance, and 300 mW power rating. The impedance specification of 29 Ohms is marginally higher than the original 25 Ohms but remains within acceptable circuit tolerance for most voltage regulation applications. Reverse leakage at 100 nA @ 17 V is slightly elevated compared to the original specification. The part is in active production with 1051 units in stock and carries full RoHS3 and MSL Level 1 compliance.

BZX84-C22,215 (Nexperia USA Inc.) — Active Status, Automotive-Qualified Alternative

This substitute is manufactured by Nexperia USA Inc. and carries AEC-Q101 automotive qualification. The 22 V nominal voltage and ±5% tolerance match the original specification. The power rating is reduced to 250 mW, which is 83% of the original 300 mW rating. The impedance specification of 55 Ohms is significantly higher than the original. This part is suitable for applications where automotive-grade qualification is required or preferred. Inventory availability is high at 2546 units.

BZX84C22-7-F (Diodes Incorporated) — Active Status, Highest Inventory Availability

This substitute maintains the 22 V nominal voltage and 300 mW power rating. The tolerance specification is ±6%, which is 1% wider than the original ±5%. The impedance specification of 55 Ohms is higher than the original. Reverse leakage is specified at 100 nA @ 15.4 V. This part offers the highest inventory availability at 35,300 units and is suitable for applications where supply chain continuity is a priority.

Selection Basis:

• All three substitutes maintain the 22 V zener voltage and SOT-23-3 package compatibility
• All three are in active production status, addressing the obsolescence of the original part
• All three carry RoHS3 compliance and MSL Level 1 ratings
• Selection among the three should be based on application-specific requirements: automotive qualification (BZX84-C22,215), impedance sensitivity (CZRT5251B-G), or supply availability (BZX84C22-7-F)

Frequently Asked Questions (FAQ)

Q: Can CZRT5251B-G be used as a direct replacement for PZM22NB,115?

A: Yes. Both parts share the same 22 V nominal zener voltage, ±5% tolerance, 300 mW power rating, and SOT-23-3 package. The impedance specification of 29 Ohms on the CZRT5251B-G is slightly higher than the original 25 Ohms, but this difference does not prevent functional substitution in standard voltage regulation circuits.

Q: Why does BZX84-C22,215 have a lower power rating (250 mW vs. 300 mW)?

A: The BZX84-C22,215 is rated at 250 mW maximum power dissipation. This 50 mW reduction may limit its use in applications requiring the full 300 mW thermal budget. Circuit design review is necessary to confirm that the reduced power rating is acceptable for the intended application.

Q: What is the significance of the ±6% tolerance on BZX84C22-7-F compared to ±5% on the original part?

A: The BZX84C22-7-F carries a ±6% zener voltage tolerance, which is 1% wider than the original ±5% specification. This means the actual zener voltage may deviate up to ±6% from the 22 V nominal value. For applications with tight voltage regulation requirements, this wider tolerance may require circuit compensation or may be unacceptable depending on system specifications.

Q: Are all three substitute parts available in the same packaging format?

A: Yes. All three substitute parts are supplied in the TO-236-3, SC-59, or SOT-23-3 package designation. The CZRT5251B-G is supplied in Tape & Reel (TR) format, the BZX84-C22,215 in Tape & Reel (TR) format, and the BZX84C22-7-F in Cut Tape (CT) & Digi-Reel® format. These packaging differences do not affect electrical or mechanical compatibility.

Q: Does BZX84-C22,215 automotive qualification (AEC-Q101) make it superior for all applications?

A: AEC-Q101 qualification indicates the part meets automotive industry reliability and quality standards. This qualification is beneficial for automotive applications but is not required for general industrial or consumer applications. Selection should be based on application requirements rather than qualification status alone.

Q: What is the impact of impedance variation across the substitute parts?

A: Impedance (Zzt) affects the dynamic response of the zener diode in transient conditions. The original PZM22NB,115 specifies 25 Ohms maximum. The CZRT5251B-G at 29 Ohms and both Nexperia and Diodes parts at 55 Ohms represent higher impedance values. Higher impedance may result in slower transient response but does not prevent substitution in most voltage regulation applications. Circuit-level analysis is recommended for noise-sensitive applications.

Q: Can these parts be used interchangeably in existing PCB designs without modification?

A: Yes. All three substitute parts use the same SOT-23-3 package footprint and pin configuration as the original PZM22NB,115. No PCB layout modifications are required for mechanical or electrical compatibility.