MM5Z18VT1 Zener Diode 18V 100mW SOD-523 Equivalent & Substitute Parts

Part Overview

The MM5Z18VT1 is a surface mount Zener diode manufactured by onsemi, rated for 18 V nominal Zener voltage with 100 mW maximum power dissipation in SOD-523 packaging. This component is classified as obsolete, necessitating identification of active equivalent and substitute parts for new designs and ongoing production requirements. The part operates across the temperature range of -65°C to 150°C and features ±6% voltage tolerance with RoHS non-compliant status.

Key Parameters

Parameter	Value	Unit
Voltage - Zener (Nom)	18	V
Tolerance	±6%	—
Power - Max	100	mW
Impedance (Max)	45	Ohms
Current - Reverse Leakage @ Vr	50	nA @ 12.6 V
Voltage - Forward (Vf) (Max) @ If	900	mV @ 10 mA
Operating Temperature	-65 to 150	°C
Mounting Type	Surface Mount	—
Package / Case	SOD-523	—

Substitute Part Grouping Explanation

Substitution of the MM5Z18VT1 is determined by the following critical parameters: nominal Zener voltage (18 V), maximum power rating, voltage tolerance, impedance characteristics, and package compatibility. Substitute parts are grouped into three categories based on their relationship to the main part specifications:

Direct Upgrade (Higher Power Rating, Same Package): Parts with identical 18 V Zener voltage, SOD-523 package, and equal or greater power dissipation capability while maintaining compatible electrical characteristics.

Similar Specification (Different Package, Enhanced Performance): Parts with 18 V Zener voltage and improved specifications (lower tolerance, higher power rating, or automotive qualification) in alternative surface mount packages (SOD-323, SOD-323F).

Parametric Equivalent (Identical Electrical Specifications): Parts with matching 18 V Zener voltage, 100 mW power rating, SOD-523 package, and equivalent electrical performance across all critical parameters.

Parameter Comparison

Part Number	Manufacturer	Vz (V)	Tolerance	Power (mW)	Zzt (Ohms)	Package	Status	RoHS
MM5Z18VT1	onsemi	18	±6%	100	45	SOD-523	Obsolete	Non-compliant
MM3Z18VT1G	onsemi	18	±6%	300	45	SOD-323	Active	ROHS3 Compliant
BZT585B18T-7	Diodes Incorporated	18	±2%	350	45	SOD-523	Active	ROHS3 Compliant
BZX585-B18,115	Nexperia USA Inc.	18	±2%	300	45	SOD-523	Active	ROHS3 Compliant
BZX585-C18,115	Nexperia USA Inc.	18	±5%	300	45	SOD-523	Active	ROHS3 Compliant
BZX84J-B18,115	Nexperia USA Inc.	18	±2%	550	20	SOD-323F	Active	ROHS3 Compliant
CZRU52C18	Comchip Technology	18	±5%	150	50	0603/SOD-523F	Active	ROHS3 Compliant
EDZVFHT2R18B	Rohm Semiconductor	18	±2.19%	150	65	SOD-523	Active	ROHS3 Compliant
BZT52C18T-TP	Micro Commercial Co	18	±5%	100	45	SOD-523	Active	ROHS3 Compliant

Engineering Selection Recommendations

For Direct Replacement (Same Package, Same Power Rating): BZT52C18T-TP from Micro Commercial Co is the primary parametric equivalent, offering identical 18 V Zener voltage, 100 mW power rating, SOD-523 package, and 45 Ohms impedance. This part is active and ROHS3 compliant, making it suitable for new designs requiring the exact electrical and mechanical footprint of the MM5Z18VT1.

For Upgraded Performance (Same Package, Higher Power Rating): BZT585B18T-7 from Diodes Incorporated and BZX585-B18,115 from Nexperia USA Inc. both provide 18 V Zener voltage in SOD-523 packaging with 300-350 mW power ratings. BZT585B18T-7 offers superior tolerance (±2%) and higher power dissipation (350 mW). BZX585-B18,115 includes automotive qualification (AEC-Q100), suitable for applications requiring enhanced reliability. Both are ROHS3 compliant and active.

For Alternative Package with Enhanced Specifications: MM3Z18VT1G from onsemi provides a direct manufacturer upgrade path with 300 mW power rating in SOD-323 package, maintaining onsemi product continuity. BZX84J-B18,115 from Nexperia USA Inc. offers the highest power rating (550 mW) in SOD-323F package with automotive qualification (AEC-Q101) and superior impedance characteristics (20 Ohms), suitable for demanding applications.

For Automotive Applications: BZX585-B18,115 (AEC-Q100) and BZX84J-B18,115 (AEC-Q101) are qualified for automotive use. EDZVFHT2R18B from Rohm Semiconductor provides AEC-Q101 qualification in SOD-523 package with 150 mW power rating.

Frequently Asked Questions (FAQ)

Q: Can BZT52C18T-TP directly replace MM5Z18VT1 without circuit modification? A: Yes. BZT52C18T-TP matches all critical electrical parameters (18 V Zener voltage, 100 mW power rating, ±5% tolerance, 45 Ohms impedance) and uses identical SOD-523 packaging. The ±5% tolerance of BZT52C18T-TP is within acceptable variance of the original ±6% specification.

Q: What is the advantage of using BZT585B18T-7 over the parametric equivalent BZT52C18T-TP? A: BZT585B18T-7 provides 350 mW power dissipation compared to 100 mW, enabling operation in higher power applications. It also features tighter ±2% voltage tolerance and maintains SOD-523 package compatibility. This part is suitable for designs requiring thermal margin or higher current handling.

Q: Is MM3Z18VT1G a suitable replacement if PCB layout allows package change? A: Yes, if the circuit board design accommodates SOD-323 package footprint. MM3Z18VT1G offers 300 mW power rating, ±6% tolerance matching the original specification, and maintains onsemi manufacturer continuity. This part is active and ROHS3 compliant.

Q: Which substitute part is recommended for automotive applications? A: BZX585-B18,115 (AEC-Q100 qualified) or BZX84J-B18,115 (AEC-Q101 qualified) are appropriate for automotive use. BZX84J-B18,115 provides higher power rating (550 mW) and lower impedance (20 Ohms) in SOD-323F package if thermal performance is critical.

Q: What tolerance differences exist among substitute parts, and does this affect circuit performance? A: Substitute parts range from ±2% (BZT585B18T-7, BZX585-B18,115, BZX84J-B18,115, EDZVFHT2R18B) to ±6% (MM3Z18VT1G) and ±5% (BZX585-C18,115, CZRU52C18, BZT52C18T-TP). Tighter tolerance (±2%) provides more precise voltage regulation. Selection depends on circuit requirements; applications requiring strict voltage regulation benefit from ±2% parts, while general-purpose applications accept ±5-6% tolerance.

Q: Can CZRU52C18 be used as a substitute despite different package designation? A: CZRU52C18 uses 0603/SOD-523F package, which differs from the original SOD-523. While electrical specifications (18 V, ±5% tolerance) are compatible, PCB footprint compatibility must be verified. This part is suitable only if the design accommodates 0603 package dimensions and the 150 mW power rating is sufficient.

Q: What is the operating temperature range consideration when selecting substitutes? A: MM5Z18VT1 operates -65°C to 150°C. Most substitutes maintain this range except CZRU52C18 (-55°C to 125°C). For applications requiring full -65°C to 150°C operation, select from BZT585B18T-7, BZX585-B18,115, BZX585-C18,115, BZX84J-B18,115, EDZVFHT2R18B, or BZT52C18T-TP.

Q: Are all substitute parts ROHS3 compliant? A: All substitute parts listed are ROHS3 compliant. The original MM5Z18VT1 is RoHS non-compliant. Substitution with any listed part ensures compliance with current RoHS3 regulations.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message