BZX84C20 Equivalent & Substitute Parts

Part Overview

The BZX84C20 is a Zener diode manufactured by onsemi, rated at 20 V nominal Zener voltage with 350 mW maximum power dissipation in a surface mount SOT-23-3 package. This part is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement. The BZX84C20 serves voltage regulation and protection applications in electronic circuits requiring stable reference voltages and transient suppression.

Key Parameters

Parameter	Value
Voltage - Zener (Nom)	20 V
Tolerance	±6%
Power - Max	350 mW
Impedance (Max)	55 Ohms
Current - Reverse Leakage @ Vr	50 nA @ 14 V
Voltage - Forward (Vf) (Max) @ If	900 mV @ 10 mA
Operating Temperature	-55°C ~ 150°C
Mounting Type	Surface Mount
Package / Case	TO-236-3, SC-59, SOT-23-3

Substitute Part Grouping Explanation

Substitution of the BZX84C20 is determined by the following critical parameters:

Primary Substitution Criteria:

Voltage - Zener (Nom): Must equal 20 V
Package / Case: Must be TO-236-3, SC-59, or SOT-23-3 compatible
Mounting Type: Must be Surface Mount
Operating Temperature Range: Must encompass or exceed -55°C to 150°C

Secondary Compatibility Parameters:

Power - Max: Substitute parts rated at 200 mW or higher are acceptable
Tolerance: Substitute parts with ±1% to ±6% tolerance are acceptable
Impedance (Max): Must be 55 Ohms or lower
Current - Reverse Leakage: Must be 100 nA @ 14 V or lower
Voltage - Forward (Vf): Must be 900 mV @ 10 mA or lower

Substitute parts meeting all primary criteria and at least the secondary compatibility parameters are electrically and mechanically interchangeable with the BZX84C20.

Parameter Comparison

Part Number	Manufacturer	Vz (Nom)	Tolerance	Power - Max	Zzt (Max)	Vf (Max) @ If	Temp Range	Package	Status
BZX84C20	onsemi	20 V	±6%	350 mW	55 Ω	900 mV @ 10 mA	-55°C ~ 150°C	SOT-23-3	Obsolete
BZX84C20LT1G	onsemi	20 V	±6%	225 mW	55 Ω	900 mV @ 10 mA	-65°C ~ 150°C	SOT-23-3	Active
SZBZX84C20LT1G	onsemi	20 V	±6%	225 mW	55 Ω	900 mV @ 10 mA	-65°C ~ 150°C	SOT-23-3	Active
BZX84-A20,215	NXP Semiconductors	20 V	±1%	250 mW	55 Ω	900 mV @ 10 mA	-65°C ~ 150°C	TO-236AB	Active
BZX84-C20,215	Nexperia USA Inc.	20 V	±5%	250 mW	55 Ω	900 mV @ 10 mA	-65°C ~ 150°C	TO-236AB	Active
BZX84-C20,235	Nexperia USA Inc.	20 V	±5%	250 mW	55 Ω	900 mV @ 10 mA	-65°C ~ 150°C	TO-236AB	Active
BZX84B20-TP	Micro Commercial Co	20 V	±2%	350 mW	55 Ω	900 mV @ 10 mA	-55°C ~ 150°C	SOT-23	Active
BZX84C20 TR	Central Semiconductor Corp	20 V	±5%	350 mW	55 Ω	900 mV @ 10 mA	-65°C ~ 150°C	SOT-23	Active
BZX84C20-7-F	Diodes Incorporated	20 V	±6%	300 mW	55 Ω	900 mV @ 10 mA	-65°C ~ 150°C	SOT-23-3	Active
BZX84C20W-7-F	Diodes Incorporated	20 V	±6%	200 mW	55 Ω	900 mV @ 10 mA	-65°C ~ 125°C	SOT-323	Active
CMPZ5250B TR PBFREE	Central Semiconductor Corp	20 V	±5%	350 mW	25 Ω	900 mV @ 10 mA	-65°C ~ 150°C	SOT-23	Active

Engineering Selection Recommendations

Direct Substitutes (Highest Compatibility):

BZX84C20LT1G and SZBZX84C20LT1G from onsemi are the primary substitutes. Both maintain identical Zener voltage (20 V), tolerance (±6%), impedance (55 Ω), and forward voltage characteristics. Both are active products with extended operating temperature ranges (-65°C to 150°C). SZBZX84C20LT1G includes AEC-Q101 automotive qualification and ROHS3 compliance, providing enhanced reliability documentation. Power rating is reduced to 225 mW, which is acceptable for applications not requiring the full 350 mW dissipation of the original part.

Alternative Substitutes (Conditional Compatibility):

BZX84-A20,215 and BZX84-C20,215/235 from NXP/Nexperia are active products with identical Zener voltage and impedance. These parts feature improved tolerance specifications (±1% for BZX84-A20,215 and ±5% for BZX84-C20 variants) and include AEC-Q101 automotive qualification. Power ratings of 250 mW are suitable for most applications. Operating temperature range extends to -65°C, exceeding the original specification.

BZX84C20 TR from Central Semiconductor Corp and BZX84B20-TP from Micro Commercial Co maintain the full 350 mW power rating and identical Zener voltage. Both are active products with SOT-23 packaging compatibility. BZX84C20 TR extends the lower operating temperature to -65°C.

BZX84C20-7-F from Diodes Incorporated provides 300 mW power dissipation with extended temperature range (-65°C to 150°C) and is actively produced.

Limited Substitutes (Specific Application Constraints):

BZX84C20W-7-F is a reduced-power variant (200 mW) in SOT-323 package. This part is suitable only for applications with lower power dissipation requirements and where the smaller SOT-323 footprint is acceptable. Operating temperature range is limited to -65°C to 125°C.

CMPZ5250B TR PBFREE from Central Semiconductor Corp maintains 350 mW power rating and extended temperature range. Impedance is reduced to 25 Ω, providing superior voltage regulation characteristics. This part is suitable for applications requiring tighter voltage regulation.

Product Status Consideration:

All substitute parts listed are active products, ensuring long-term availability and supply chain stability compared to the obsolete BZX84C20.

Frequently Asked Questions (FAQ)

Q: Can BZX84C20LT1G directly replace BZX84C20 in existing designs?

A: Yes. BZX84C20LT1G is electrically and mechanically compatible. Both parts share identical Zener voltage (20 V), tolerance (±6%), impedance (55 Ω), and forward voltage characteristics. The reduced power rating (225 mW vs. 350 mW) is acceptable unless the application requires the full 350 mW dissipation. BZX84C20LT1G is an active product, providing superior supply availability.

Q: What is the difference between BZX84C20LT1G and SZBZX84C20LT1G?

A: Both parts are electrically identical with 20 V Zener voltage, ±6% tolerance, and 225 mW power rating. SZBZX84C20LT1G includes AEC-Q101 automotive qualification and is designated for automotive applications. SZBZX84C20LT1G is the preferred choice for automotive or mission-critical applications requiring documented qualification.

Q: Are NXP BZX84-A20,215 and BZX84-C20,215 interchangeable with onsemi BZX84C20?

A: Yes, with noted differences. Both NXP parts maintain 20 V Zener voltage, 55 Ω impedance, and SOT-23-3 package compatibility. BZX84-A20,215 offers superior tolerance (±1% vs. ±6%), while BZX84-C20,215 matches the original tolerance at ±5%. Power ratings are 250 mW, which is acceptable for most applications. Both include AEC-Q101 automotive qualification and extended temperature range (-65°C to 150°C).

Q: Can I use BZX84C20W-7-F as a substitute?

A: BZX84C20W-7-F is a substitute only for applications with lower power dissipation requirements. This part is rated at 200 mW (vs. 350 mW for the original) and uses SOT-323 packaging instead of SOT-23-3. The smaller package may require PCB layout modifications. Operating temperature range is limited to -65°C to 125°C, which may not meet all application requirements.

Q: What is the advantage of CMPZ5250B TR PBFREE over other substitutes?

A: CMPZ5250B TR PBFREE maintains the full 350 mW power rating and extended temperature range (-65°C to 150°C). The impedance is reduced to 25 Ω, providing superior voltage regulation characteristics compared to the 55 Ω impedance of the original part. This part is suitable for applications requiring tighter voltage regulation performance.

Q: Are all substitute parts RoHS compliant?

A: Most substitute parts listed are ROHS3 compliant. The original BZX84C20 does not specify RoHS status. All active substitute parts from onsemi, NXP, Nexperia, Diodes Incorporated, and Central Semiconductor Corp are ROHS3 compliant, meeting current environmental and regulatory requirements.

Q: What packaging options are available for 20 V Zener diode substitutes?

A: Substitute parts are available in SOT-23-3 (TO-236-3, SC-59), TO-236AB, SOT-23, and SOT-323 packages. SOT-23-3 and TO-236AB packages are mechanically and electrically compatible with the original BZX84C20. SOT-323 (BZX84C20W-7-F) requires PCB layout modifications due to smaller footprint. All packages are surface mount types.

Q: Which substitute part offers the best long-term availability?

A: BZX84C20LT1G and SZBZX84C20LT1G from onsemi, along with NXP/Nexperia BZX84-A20,215 and BZX84-C20 variants, are established active products from major semiconductor manufacturers with extensive distribution networks. These parts offer the highest probability of sustained availability and supply chain stability.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message