MMSZ4685T1 Zener Diode Equivalent & Substitute Parts

Part Overview

The MMSZ4685T1 is a 3.6 V, 500 mW Zener diode manufactured by onsemi in SOD-123 surface mount packaging. This component is classified as obsolete, making identification of equivalent and substitute parts essential for ongoing design support and production continuity. The part operates across a temperature range of -55°C to 150°C with ±5% voltage tolerance and is RoHS non-compliant. Direct replacements and functional equivalents are available from multiple manufacturers with improved product status and compliance certifications.

Key Parameters

Parameter	Value	Unit
Voltage - Zener (Nom)	3.6	V
Tolerance	±5	%
Power - Max	500	mW
Current - Reverse Leakage @ Vr	7.5	µA @ 2 V
Voltage - Forward (Vf) (Max) @ If	900	mV @ 10 mA
Operating Temperature	-55 to 150	°C
Mounting Type	Surface Mount
Package / Case	SOD-123

Substitute Part Grouping Explanation

Substitution of the MMSZ4685T1 is determined by the following critical parameters: nominal Zener voltage (3.6 V), voltage tolerance (±5%), maximum power dissipation capability, reverse leakage current characteristics, forward voltage drop, operating temperature range, and surface mount package type. Substitute parts are grouped into three categories based on electrical and mechanical compatibility:

Direct Equivalent (Identical Specifications): Parts matching all electrical parameters and SOD-123 packaging with active product status and improved compliance.

Upgrade Equivalent (Enhanced Operating Range): Parts with identical electrical specifications but extended lower operating temperature limit, maintaining SOD-123 packaging.

Similar Equivalent (Reduced Power Rating or Package Variant): Parts with matching Zener voltage and tolerance but reduced power dissipation or alternative surface mount packaging, suitable for applications with lower power requirements or specific package constraints.

Parameter Comparison

Parameter	MMSZ4685T1 (Main)	MMSZ4685T1G (Direct)	DDZ9685-7 (Upgrade)	BZT52H-C3V6,115 (Similar)	MMSZ4685-TP (Similar)	PZU3.6BA,115 (Similar)
Manufacturer	onsemi	onsemi	Diodes Incorporated	Nexperia USA Inc.	Micro Commercial Co	NXP USA Inc.
Voltage - Zener (Nom)	3.6 V	3.6 V	3.6 V	3.6 V	3.6 V	3.6 V
Tolerance	±5%	±5%	±5%	±5%	±5%	±5%
Power - Max	500 mW	500 mW	500 mW	375 mW	500 mW	320 mW
Current - Reverse Leakage @ Vr	7.5 µA @ 2 V	7.5 µA @ 2 V	7.5 µA @ 2 V	5 µA @ 1 V	7.5 µA @ 2 V	5 µA @ 1 V
Voltage - Forward (Vf) (Max) @ If	900 mV @ 10 mA	900 mV @ 10 mA	900 mV @ 10 mA	900 mV @ 10 mA	950 mV @ 10 mA	1.1 V @ 100 mA
Operating Temperature	-55 to 150°C	-55 to 150°C	-65 to 150°C	-65 to 150°C	-55 to 150°C	-55 to 150°C
Package / Case	SOD-123	SOD-123	SOD-123	SOD-123F	SOD-123	SOD-323
Product Status	Obsolete	Active	Active	Active	Active	Active
RoHS Status	Non-compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	Not specified

Engineering Selection Recommendations

MMSZ4685T1G is the primary direct equivalent replacement. This onsemi part maintains identical electrical specifications and SOD-123 packaging while offering active product status and ROHS3 compliance. Inventory availability is significantly higher (21,405 units) compared to the obsolete MMSZ4685T1, ensuring supply chain continuity.

DDZ9685-7 from Diodes Incorporated provides an upgrade path with extended lower operating temperature limit (-65°C versus -55°C) while maintaining all other electrical parameters and SOD-123 packaging. This part carries active product status and ROHS3 compliance, suitable for applications requiring enhanced cold-temperature performance.

BZT52H-C3V6,115 from Nexperia USA Inc. is suitable for applications where power dissipation requirements are reduced to 375 mW or lower. This part includes automotive-grade qualification (AEC-Q101) and operates across -65°C to 150°C. The SOD-123F package is mechanically compatible with SOD-123 footprints in most applications. ROHS3 compliance is confirmed.

MMSZ4685-TP from Micro Commercial Co maintains full 500 mW power rating and SOD-123 packaging with active product status and ROHS3 compliance. Forward voltage specification is marginally higher (950 mV @ 10 mA versus 900 mV), which may be significant in precision voltage regulation circuits.

PZU3.6BA,115 from NXP USA Inc. is applicable only for applications with power dissipation requirements of 320 mW or lower. This part uses SOD-323 packaging, which is physically smaller than SOD-123 and requires PCB layout modification. Forward voltage is specified at a different test condition (1.1 V @ 100 mA), limiting direct comparison.

Frequently Asked Questions (FAQ)

Q: Can MMSZ4685T1G be used as a direct replacement for MMSZ4685T1?

A: Yes. MMSZ4685T1G is a direct equivalent with identical electrical specifications (3.6 V nominal, 500 mW, ±5% tolerance) and SOD-123 packaging. The primary advantages are active product status and ROHS3 compliance. No circuit modifications are required.

Q: What is the difference between MMSZ4685T1G and DDZ9685-7?

A: Both parts are electrically identical with 3.6 V nominal voltage and 500 mW power rating in SOD-123 packaging. DDZ9685-7 extends the lower operating temperature limit to -65°C (versus -55°C for MMSZ4685T1G). Selection depends on whether the application requires operation below -55°C.

Q: Can BZT52H-C3V6,115 replace MMSZ4685T1 in all applications?

A: BZT52H-C3V6,115 is suitable only for applications where power dissipation does not exceed 375 mW. The part uses SOD-123F packaging, which is mechanically compatible with SOD-123 footprints. Applications requiring full 500 mW dissipation capability must use MMSZ4685T1G, DDZ9685-7, or MMSZ4685-TP.

Q: What are the implications of using MMSZ4685-TP instead of MMSZ4685T1G?

A: MMSZ4685-TP maintains identical power rating (500 mW) and SOD-123 packaging. The forward voltage specification is 950 mV @ 10 mA compared to 900 mV @ 10 mA for MMSZ4685T1G. This 50 mV difference may affect precision voltage regulation circuits but is acceptable for general-purpose applications.

Q: Is PZU3.6BA,115 compatible with the original MMSZ4685T1 footprint?

A: PZU3.6BA,115 uses SOD-323 packaging, which is physically smaller than SOD-123. PCB layout modification is required for footprint compatibility. This part is suitable only for applications with power dissipation requirements of 320 mW or lower and where package size reduction is beneficial.

Q: Which substitute part offers the best compliance and supply availability?

A: MMSZ4685T1G offers the optimal combination of direct electrical equivalence, active product status, ROHS3 compliance, and highest inventory availability (21,405 units). This part is the recommended primary replacement for the obsolete MMSZ4685T1.

Q: Are all substitute parts RoHS compliant?

A: MMSZ4685T1G, DDZ9685-7, BZT52H-C3V6,115, and MMSZ4685-TP are all ROHS3 compliant. RoHS status for PZU3.6BA,115 is not specified in the provided data.

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