ZMM5259B-7 Equivalent & Substitute Parts

Part Overview

The ZMM5259B-7 is a Zener diode rated at 39 V nominal voltage with 500 mW power dissipation, manufactured by Diodes Incorporated in Mini MELF surface mount packaging. This component is classified as obsolete, necessitating identification of functionally equivalent alternatives for ongoing design support and procurement. Substitute parts maintain the core electrical specifications while offering active product status and improved availability through alternative packaging formats and manufacturers.

Key Parameters

Parameter	Value	Unit
Voltage - Zener (Nom)	39	V
Tolerance	±5%	-
Power - Max	500	mW
Impedance (Max)	80	Ohms
Current - Reverse Leakage @ Vr	100	nA @ 30 V
Voltage - Forward (Vf) (Max) @ If	1.5	V @ 200 mA
Operating Temperature Range	-65 to 175	°C
Mounting Type	Surface Mount	-
Package / Case	DO-213AC, MINI-MELF, SOD-80	-
RoHS Status	ROHS3 Compliant	-
Product Status	Obsolete	-

Substitute Part Grouping Explanation

Substitution eligibility is determined by the following critical parameters:

Primary Electrical Equivalence Criteria:

Voltage - Zener (Nom): 39 V
Power - Max: 500 mW
Tolerance: ±5% (primary specification; ±2%, ±10%, ±20% variants acceptable with tolerance trade-offs)
Operating Temperature Range: -65°C to 175°C minimum
Mounting Type: Surface Mount

Secondary Compatibility Criteria:

Impedance (Max): 80 Ohms nominal (up to 90 Ohms acceptable)
Current - Reverse Leakage @ Vr: 100 nA @ 30 V (lower values acceptable)
Voltage - Forward (Vf) (Max) @ If: 1.5 V @ 200 mA (lower values acceptable)

Package Compatibility: Substitutes are grouped by package type: SOD-123 (smaller footprint), DO-213AA/AB (MELF variants), and SOD-80 MiniMELF (direct form factor match). All maintain surface mount configuration.

Compliance Considerations: RoHS3 compliance preferred for new designs. REACH compliance status noted where applicable.

Parameter Comparison

Manufacturer Part Number	Manufacturer	Vz (V)	Tolerance	Power (mW)	Zzt (Ohms)	Vf @ If (V)	Temp Range (°C)	Package	Product Status	RoHS
ZMM5259B-7	Diodes Inc.	39	±5%	500	80	1.5 @ 200mA	-65 to 175	DO-213AC MINI-MELF	Obsolete	ROHS3
MMSZ5259B-7-F	Diodes Inc.	39	±5%	500	80	0.9 @ 10mA	-65 to 150	SOD-123	Active	ROHS3
1N5259BUR-1	Microchip	39	±5%	500	80	1.1 @ 200mA	-65 to 175	DO-213AA	Active	Non-compliant
BZV55C39	Microchip	39	±5%	-	-	1.1 @ 200mA	-65 to 175	DO-213AA	Active	Non-compliant
CDLL5259	Microchip	39	±20%	-	80	1.1 @ 200mA	-65 to 175	DO-213AB MELF	Active	Non-compliant
CDLL5259A	Microchip	39	±10%	-	80	1.1 @ 200mA	-65 to 175	DO-213AB MELF	Active	Non-compliant
CDLL5259B	Microchip	39	±5%	-	80	1.1 @ 200mA	-65 to 175	DO-213AB MELF	Active	Non-compliant
TLZ39-GS18	Vishay	39	-	500	85	1.5 @ 200mA	-65 to 175	DO-213AC MINI-MELF	Active	ROHS3
TLZ39G-GS08	Vishay	39	-	500	85	1.5 @ 200mA	-65 to 175	DO-213AC MINI-MELF	Active	ROHS3
TZMB39-GS08	Vishay	39	±2%	500	90	1.5 @ 200mA	-65 to 175	DO-213AC MINI-MELF	Active	ROHS3
TZMB39-GS18	Vishay	39	±2%	500	90	1.5 @ 200mA	-65 to 175	DO-213AC MINI-MELF	Active	ROHS3

Engineering Selection Recommendations

Direct Form Factor Replacement (Recommended for Retrofit):

TZMB39-GS08 and TZMB39-GS18 provide direct mechanical and electrical compatibility with the ZMM5259B-7. Both maintain the DO-213AC MINI-MELF package, 39 V nominal voltage, 500 mW power rating, and -65°C to 175°C operating range. These Vishay components offer superior tolerance specification (±2% versus ±5%), ROHS3 compliance, and active product status. TZMB39-GS08 is available in Cut Tape & Digi-Reel packaging with 45,300 units in stock; TZMB39-GS18 is available in Tape & Reel with 1,102 units in stock. Both carry AEC-Q101 automotive qualification.

TLZ39-GS18 and TLZ39G-GS08 also provide identical package compatibility and electrical performance with ROHS3 compliance and active status, though with unspecified tolerance and lower impedance specification (85 Ohms).

Alternative Package Options:

MMSZ5259B-7-F (Diodes Incorporated, SOD-123) maintains manufacturer continuity and ROHS3 compliance with active product status. The SOD-123 package offers reduced footprint for space-constrained applications. Operating temperature range is limited to -65°C to 150°C. This part is suitable for applications not requiring the full 175°C upper temperature limit.

Microchip DO-213AA/AB Variants:

1N5259BUR-1, BZV55C39, CDLL5259, CDLL5259A, and CDLL5259B provide electrical equivalence with extended availability. These parts are RoHS non-compliant and require compliance verification for new designs. CDLL5259B offers ±5% tolerance matching the original specification. All support the full -65°C to 175°C operating range.

Product Status Consideration:

All substitute parts listed carry active product status, ensuring long-term availability and supply chain stability compared to the obsolete ZMM5259B-7.

Frequently Asked Questions (FAQ)

Q: Can MMSZ5259B-7-F replace ZMM5259B-7 in all applications?

A: MMSZ5259B-7-F is electrically equivalent with identical voltage, tolerance, and power specifications. The primary difference is package format (SOD-123 versus MINI-MELF) and maximum operating temperature (150°C versus 175°C). Substitution is valid for applications operating below 150°C. PCB layout modifications are required due to different package footprints.

Q: What is the difference between TZMB39-GS08 and TZMB39-GS18?

A: Both parts are electrically identical 39 V, 500 mW Zener diodes in DO-213AC MINI-MELF packaging with ±2% tolerance and AEC-Q101 qualification. The difference is packaging format: GS08 is supplied in Cut Tape & Digi-Reel; GS18 is supplied in Tape & Reel. Selection depends on assembly equipment compatibility and procurement volume requirements.

Q: Why do some substitute parts lack power rating specifications?

A: BZV55C39, CDLL5259, CDLL5259A, and CDLL5259B datasheets provided do not include explicit maximum power ratings in the supplied parameters. These parts maintain 39 V nominal voltage and ±5% or tighter tolerance specifications. Detailed datasheets should be consulted for complete thermal and power dissipation characteristics before final selection.

Q: Is RoHS compliance required for substitution?

A: RoHS3 compliance is preferred for new designs and required in many regulated markets. TZMB39-GS08, TZMB39-GS18, TLZ39-GS18, TLZ39G-GS08, and MMSZ5259B-7-F are ROHS3 compliant. Microchip variants (1N5259BUR-1, BZV55C39, CDLL5259, CDLL5259A, CDLL5259B) are RoHS non-compliant and require compliance assessment for target applications.

Q: Can tolerance differences affect circuit performance?

A: Yes. The ZMM5259B-7 specifies ±5% tolerance. TZMB39-GS08 and TZMB39-GS18 offer superior ±2% tolerance, reducing voltage variation and improving circuit stability. CDLL5259 offers ±20% tolerance, which may be insufficient for precision voltage regulation applications. CDLL5259A provides ±10% tolerance as a compromise option. Tolerance selection depends on circuit requirements for zener voltage accuracy.

Q: What is the significance of impedance (Zzt) specifications?

A: Impedance affects dynamic voltage regulation performance. The ZMM5259B-7 specifies 80 Ohms maximum impedance. TZMB39-GS08 and TZMB39-GS18 specify 90 Ohms, which is acceptable for most applications. Lower impedance values (TLZ39 series at 85 Ohms) provide marginally better transient response. Impedance differences are typically negligible in applications with adequate filtering and load regulation.

Q: Are Vishay and Microchip parts interchangeable with Diodes Incorporated parts?

A: Electrical interchangeability is determined by matching voltage, tolerance, power rating, and operating temperature specifications, not manufacturer. TZMB39-GS08 and TZMB39-GS18 are direct functional equivalents to ZMM5259B-7 despite different manufacturers. Microchip variants are functionally equivalent but with compliance and tolerance trade-offs. Mechanical compatibility depends on package type matching.

Q: What is the impact of forward voltage (Vf) differences?

A: Forward voltage specifications apply to forward-biased diode operation, not reverse-biased zener operation. Differences between 0.9 V, 1.1 V, and 1.5 V at specified test currents have minimal impact on zener regulation performance. These parameters are relevant only if the diode is used in forward-biased applications or if reverse recovery characteristics are critical.

Q: Should I select parts with lower reverse leakage current?

A: Lower reverse leakage current (e.g., TLZ39G-GS08 at 40 nA @ 37 V versus ZMM5259B-7 at 100 nA @ 30 V) improves circuit performance in high-impedance applications and reduces standby power consumption. For most standard voltage regulation applications, the specified 100 nA leakage is acceptable. Selection should be based on specific circuit requirements for leakage sensitivity.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message