MMSZ4706 Zener Diode 19V 500mW SOD-123 Equivalent & Substitute Parts

Part Overview

The MMSZ4706 is a 19 V, 500 mW Zener diode manufactured by onsemi in SOD-123 surface mount packaging. This component is classified as obsolete, though 4400 pieces remain in stock as new original inventory. The MMSZ4706 serves voltage regulation and protection applications requiring a nominal Zener voltage of 19 V with ±5% tolerance and 500 mW power dissipation capability.

Due to the obsolete product status, equivalent and substitute parts are necessary for ongoing design support, production continuity, and long-term component availability. Active alternatives with identical or comparable electrical specifications are available from multiple manufacturers.

Key Parameters

Parameter	Value	Unit
Voltage - Zener (Nom)	19	V
Tolerance	±5%	%
Power - Max	500	mW
Current - Reverse Leakage @ Vr	50	nA @ 14.4 V
Voltage - Forward (Vf) (Max) @ If	900	mV @ 10 mA
Operating Temperature Range	-55°C ~ 150°C	°C
Mounting Type	Surface Mount	—
Package / Case	SOD-123	—
Moisture Sensitivity Level (MSL)	1 (Unlimited)	—

Substitute Part Grouping Explanation

Substitute parts for the MMSZ4706 are classified into two categories based on electrical parameter alignment:

Direct Substitutes (Identical Electrical Specifications)

Direct substitutes maintain all critical electrical parameters: 19 V nominal Zener voltage, ±5% tolerance, 500 mW maximum power dissipation, 900 mV forward voltage at 10 mA, and -55°C to 150°C operating temperature range. These parts differ only in product status (active versus obsolete), packaging format (tape & reel versus bulk), or manufacturer identity. Direct substitutes include MMSZ4706T1G, MMSZ5249BT1G, SZMMSZ5249BT1G, and MMSZ5249B-G3-08.

Similar Substitutes (Comparable Electrical Specifications)

Similar substitutes maintain the core 19 V Zener voltage specification and SOD-123 package format but exhibit variations in one or more secondary parameters such as maximum power dissipation, reverse leakage current, impedance, or operating temperature range. These parts are suitable for applications where the parameter variations do not impact circuit performance. Similar substitutes include BZT52H-C20,115 (20 V, 375 mW), DDZ20CQ-7 (19.73 V, 310 mW), MMSZ5249B-G3-18, and MMSZ5249B-G3-08.

Key Parameters Determining Substitution:

Nominal Zener voltage (19 V ±5%)
Maximum power dissipation (500 mW or higher)
Forward voltage characteristic (900 mV @ 10 mA)
Operating temperature range (-55°C to 150°C minimum)
Surface mount SOD-123 package compatibility

Parameter Comparison

Part Number	Manufacturer	Product Status	Vz (Nom)	Tolerance	Power Max	Vf (Max) @ If	Temp Range	Package	Packaging Type
MMSZ4706	onsemi	Obsolete	19 V	±5%	500 mW	900 mV @ 10 mA	-55°C ~ 150°C	SOD-123	—
MMSZ4706T1G	onsemi	Active	19 V	±5%	500 mW	900 mV @ 10 mA	-55°C ~ 150°C	SOD-123	Tape & Reel
MMSZ5249BT1G	Fairchild Semiconductor	Active	19 V	±5%	500 mW	900 mV @ 10 mA	-55°C ~ 150°C	SOD-123	Bulk
SZMMSZ5249BT1G	onsemi	Active	19 V	±5%	500 mW	900 mV @ 10 mA	-55°C ~ 150°C	SOD-123	Tape & Reel
MMSZ5249B-G3-08	Vishay General Semiconductor	Active	19 V	±5%	500 mW	900 mV @ 10 mA	-55°C ~ 150°C	SOD-123	Tape & Reel
MMSZ5249B-G3-18	Vishay General Semiconductor	Active	19 V	±5%	500 mW	900 mV @ 10 mA	-55°C ~ 150°C	SOD-123	Tape & Reel
DDZ20CQ-7	Diodes Incorporated	Active	19.73 V	±3%	310 mW	900 mV @ 10 mA	-65°C ~ 150°C	SOD-123	Tape & Reel
BZT52H-C20,115	Nexperia USA Inc.	Active	20 V	±5%	375 mW	900 mV @ 10 mA	-65°C ~ 150°C	SOD-123F	Tape & Reel

Engineering Selection Recommendations

Primary Recommendation: MMSZ4706T1G

MMSZ4706T1G is the direct equivalent of the obsolete MMSZ4706, manufactured by onsemi with identical electrical specifications. This part maintains active product status with 7915 pieces in stock. The only difference is packaging format (tape & reel versus unspecified bulk format). MMSZ4706T1G is ROHS3 compliant and carries REACH Unaffected status, matching the regulatory profile of the original part.

Secondary Recommendation: SZMMSZ5249BT1G

SZMMSZ5249BT1G is an onsemi-manufactured direct substitute with identical electrical specifications and active product status. This part is qualified to AEC-Q101 automotive standard and carries the SZMMSZ52xxxT1G series designation. With 66300 pieces in stock, SZMMSZ5249BT1G offers superior availability. ROHS3 compliance and REACH Unaffected status are confirmed.

Tertiary Recommendation: MMSZ5249BT1G

MMSZ5249BT1G, manufactured by Fairchild Semiconductor, provides direct electrical equivalence with active product status and 12300 pieces in inventory. This part is supplied in bulk packaging and maintains identical voltage, tolerance, power, and temperature specifications.

Alternative Recommendation: MMSZ5249B-G3-08

MMSZ5249B-G3-08, manufactured by Vishay General Semiconductor, is a direct electrical substitute with active status and 780 pieces available. This part is suitable for applications where Vishay component qualification is required.

Conditional Recommendation: DDZ20CQ-7

DDZ20CQ-7, manufactured by Diodes Incorporated, is a similar substitute with 19.73 V nominal Zener voltage (within ±5% tolerance of 19 V specification) and AEC-Q101 automotive qualification. Maximum power dissipation is reduced to 310 mW. This part is suitable for applications where the lower power rating does not constrain circuit design and automotive-grade qualification is beneficial.

Not Recommended: BZT52H-C20,115

BZT52H-C20,115 exhibits a 20 V nominal Zener voltage, which exceeds the ±5% tolerance band of the 19 V specification. Additionally, maximum power dissipation is reduced to 375 mW, and the package variant is SOD-123F rather than SOD-123. This part is suitable only for applications where 20 V regulation is acceptable and power dissipation requirements are lower.

Frequently Asked Questions (FAQ)

Q: Can MMSZ4706T1G be used as a direct replacement for MMSZ4706?

A: Yes. MMSZ4706T1G is manufactured by onsemi with identical electrical specifications: 19 V nominal Zener voltage, ±5% tolerance, 500 mW maximum power dissipation, 900 mV forward voltage at 10 mA, and -55°C to 150°C operating temperature range. The part is active and widely available. The only difference is packaging format (tape & reel).

Q: What is the difference between MMSZ4706T1G and SZMMSZ5249BT1G?

A: Both parts are manufactured by onsemi with identical electrical specifications. SZMMSZ5249BT1G carries AEC-Q101 automotive qualification and belongs to the SZMMSZ52xxxT1G series, making it suitable for automotive applications. MMSZ4706T1G is the direct onsemi equivalent without automotive qualification. SZMMSZ5249BT1G offers significantly higher inventory availability (66300 pieces versus 7915 pieces).

Q: Can DDZ20CQ-7 replace MMSZ4706 in all applications?

A: DDZ20CQ-7 is a similar substitute with comparable but not identical specifications. The nominal Zener voltage is 19.73 V (within ±5% tolerance of 19 V), but maximum power dissipation is reduced to 310 mW. This part is suitable only for applications where the lower power rating does not exceed circuit requirements. DDZ20CQ-7 carries AEC-Q101 automotive qualification and ±3% tolerance, which may be beneficial in precision applications.

Q: What is the significance of the SOD-123F package variant in BZT52H-C20,115?

A: BZT52H-C20,115 uses SOD-123F packaging, which differs from the SOD-123 package of MMSZ4706. While both are surface mount diode packages, SOD-123F has different mechanical dimensions and land pattern requirements. PCB layout and footprint modifications are necessary for BZT52H-C20,115 substitution. Additionally, the 20 V nominal Zener voltage exceeds the ±5% tolerance specification of the 19 V requirement.

Q: Are all substitute parts ROHS3 compliant?

A: MMSZ4706T1G, SZMMSZ5249BT1G, MMSZ5249BT1G, MMSZ5249B-G3-08, MMSZ5249B-G3-18, DDZ20CQ-7, and BZT52H-C20,115 are all confirmed ROHS3 compliant. All parts carry REACH Unaffected status.

Q: Which substitute offers the best inventory availability?

A: SZMMSZ5249BT1G offers the highest inventory availability with 66300 pieces in stock. This part is manufactured by onsemi with identical electrical specifications to MMSZ4706 and carries AEC-Q101 automotive qualification.

Q: Can MMSZ5249BT1G be used in automotive applications?

A: MMSZ5249BT1G is manufactured by Fairchild Semiconductor and does not carry AEC-Q101 automotive qualification. For automotive applications, SZMMSZ5249BT1G (onsemi, AEC-Q101 qualified) or DDZ20CQ-7 (Diodes Incorporated, AEC-Q101 qualified) are appropriate selections.

Q: What is the difference between MMSZ5249B-G3-08 and MMSZ5249B-G3-18?

A: Both parts are manufactured by Vishay General Semiconductor with identical electrical specifications. The designations "-G3-08" and "-G3-18" indicate different manufacturing date codes or tape reel configurations. Electrical performance and compatibility are equivalent.

Q: Is the ±3% tolerance of DDZ20CQ-7 better than the ±5% tolerance of MMSZ4706?

A: DDZ20CQ-7 provides tighter tolerance (±3% versus ±5%), which may be beneficial for precision voltage regulation applications. However, the nominal Zener voltage of 19.73 V and reduced maximum power dissipation of 310 mW must be evaluated against circuit requirements. Tighter tolerance does not constitute a universal advantage if other electrical parameters are insufficient.

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