CZRT55C39-G Zener Diode 39V 350mW SOT-23-3 Equivalent & Substitute Parts

Part Overview

The CZRT55C39-G is a 39V Zener diode manufactured by Comchip Technology, rated for 350mW maximum power dissipation in a surface mount SOT-23-3 package. This component is classified as Active product status with full RoHS3 compliance and unlimited moisture sensitivity rating (MSL 1). Zener diodes of this specification are used in voltage regulation, overvoltage protection, and reference voltage circuits. Equivalent and substitute parts are identified based on matching electrical characteristics and mechanical compatibility to ensure functional interchangeability in circuit applications.

Substiute Parts

CZRT55C39-G

Comchip TechnologyIn Stock: 1080CZRT55C39-G Datasheet

Current PartRFQ

MMBZ5259B-7-F

Diodes IncorporatedIn Stock: 17347MMBZ5259B-7-F Datasheet

DirectRFQ

BZX84B39-7-F

Diodes IncorporatedIn Stock: 3389BZX84B39-7-F Datasheet

MFR RecommendedRFQ

BZX84B39Q-7-F

Diodes IncorporatedIn Stock: 2430BZX84B39Q-7-F Datasheet

MFR RecommendedRFQ

BZX84C39-7-F

Diodes IncorporatedIn Stock: 47196BZX84C39-7-F Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the CZRT55C39-G is determined by the following critical parameters:

Primary Matching Criteria:

• Zener voltage (Vz): 39V nominal
• Package type: SOT-23-3 (TO-236-3, SC-59)
• Mounting: Surface Mount
• Operating temperature range: -65°C to 150°C minimum
• RoHS3 compliance and MSL 1 rating

Secondary Compatibility Factors:

• Power rating: 350mW or higher
• Voltage tolerance: ±5% or tighter
• Forward voltage and reverse leakage characteristics within specified limits

Substitute parts are grouped into two categories based on power rating alignment:

Category A - Full Power Rating Match (350mW): Parts maintaining the original 350mW specification with identical or superior electrical characteristics.

Category B - Reduced Power Rating (300mW): Parts with 300mW maximum power, suitable for applications where full 350mW dissipation is not required.

Parameter Comparison

Engineering Selection Recommendations

MMBZ5259B-7-F (Diodes Incorporated)

This part provides direct substitution with matching 350mW power rating and 39V nominal zener voltage. The ±5% tolerance aligns with the main part specification. The impedance of 80 Ohms is lower than the main part's 130 Ohms, resulting in improved voltage regulation characteristics. All compliance certifications (RoHS3, MSL 1) are equivalent. This part is recommended for applications requiring full 350mW dissipation capability with superior impedance performance.

BZX84B39-7-F (Diodes Incorporated)

This part maintains 350mW power rating with tighter ±2% voltage tolerance compared to the main part's ±5%. Impedance and reverse leakage specifications match the main part exactly. The tighter tolerance provides enhanced voltage accuracy for precision regulation circuits. Suitable for applications where improved voltage stability is required without power derating.

BZX84B39Q-7-F (Diodes Incorporated)

This part features ±2% voltage tolerance and AEC-Q101 automotive qualification. Power rating is reduced to 300mW. Recommended for automotive-grade applications or where tighter voltage tolerance is specified. Not suitable for applications requiring full 350mW dissipation.

BZX84C39-7-F (Diodes Incorporated)

This part provides ±5% tolerance matching the main part with reduced 300mW power rating. Impedance and leakage characteristics are identical to the main part. Highest inventory availability (47,100 pcs). Suitable for applications where 300mW dissipation is sufficient and cost optimization is prioritized.

Frequently Asked Questions (FAQ)

Q: Can MMBZ5259B-7-F replace CZRT55C39-G in all applications?

A: Yes, for applications within 350mW power dissipation limits. The MMBZ5259B-7-F provides equivalent zener voltage, power rating, and package compatibility. The lower impedance (80 Ohms vs. 130 Ohms) may improve regulation performance in some circuits.

Q: What is the difference between ±2% and ±5% tolerance parts?

A: Tolerance specifies the allowable deviation from the nominal 39V zener voltage. ±2% tolerance (BZX84B39-7-F, BZX84B39Q-7-F) provides tighter voltage accuracy (±0.78V) compared to ±5% tolerance (CZRT55C39-G, MMBZ5259B-7-F, BZX84C39-7-F) which allows ±1.95V deviation. Select ±2% parts for precision voltage reference applications.

Q: Are 300mW parts suitable replacements for 350mW applications?

A: Only if the circuit design ensures power dissipation does not exceed 300mW. BZX84B39Q-7-F and BZX84C39-7-F are not suitable for applications requiring the full 350mW capability. Verify thermal design and current limiting before substitution.

Q: Does AEC-Q101 qualification affect substitution compatibility?

A: AEC-Q101 qualification (BZX84B39Q-7-F) indicates automotive-grade reliability testing. It does not affect electrical interchangeability but is required for automotive applications. Non-automotive applications can use any listed substitute.

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

A: Yes, all listed substitutes use SOT-23-3 package (TO-236-3, SC-59 equivalent designations). Pin configuration and PCB footprint are identical, enabling direct board-level substitution.

Q: What is the significance of impedance differences?

A: Impedance affects voltage regulation quality. Lower impedance (MMBZ5259B-7-F at 80 Ohms) provides better load regulation and faster transient response. Higher impedance (130 Ohms) is acceptable for general-purpose applications. Select based on circuit regulation requirements.

Q: Can I use BZX84C39-7-F due to higher inventory availability?

A: Yes, if your application permits 300mW power dissipation and ±5% voltage tolerance. The 47,100 pcs inventory availability makes this part suitable for high-volume production. Verify power budget before selection.