BZX84C30 Zener Diode Equivalent & Substitute Parts

Part Overview

The BZX84C30 is a 30 V Zener diode manufactured by onsemi, rated for 350 mW power dissipation in a surface mount SOT-23-3 package. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement. The BZX84C30 serves as a voltage regulation and transient protection element in electronic circuits requiring 30 V reference voltage with ±7% tolerance.

Key Parameters

Parameter	Value	Unit
Voltage - Zener (Nom)	30	V
Tolerance	±7%	—
Power - Max	350	mW
Impedance (Max)	80	Ohms
Current - Reverse Leakage @ Vr	50	nA @ 21 V
Voltage - Forward (Vf) (Max) @ If	900	mV @ 10 mA
Operating Temperature	-55 to 150	°C
Mounting Type	Surface Mount	—
Package / Case	TO-236-3, SC-59, SOT-23-3	—

Substitute Part Grouping Explanation

Substitution of the BZX84C30 is determined by the following critical parameters:

Primary Matching Criteria:

Voltage - Zener (Nom): 30 V (exact match required)
Impedance (Max): 80 Ohms (exact match required)
Mounting Type: Surface Mount
Package / Case: TO-236-3, SC-59, SOT-23-3 (or compatible variants)

Secondary Compatibility Factors:

Power - Max: 350 mW or greater (equal or higher rating acceptable)
Tolerance: ±7% or tighter (±5%, ±2% acceptable)
Operating Temperature: -55°C to 150°C minimum range
Current - Reverse Leakage @ Vr: 50 nA or lower (equal or lower acceptable)
Voltage - Forward (Vf) (Max) @ If: 900 mV @ 10 mA or lower

Substitute parts are grouped by their ability to meet or exceed these parameters while maintaining functional equivalence in circuit applications.

Parameter Comparison

Part Number	Manufacturer	Vz (V)	Tolerance	Power (mW)	Zzt (Ohms)	Ir @ Vr (nA)	Vf (mV)	Temp Range (°C)	Package	Status
BZX84C30	onsemi	30	±7%	350	80	50 @ 21V	900 @ 10mA	-55 to 150	SOT-23-3	Obsolete
BZX84C30LT1G	onsemi	30	±7%	225	80	50 @ 21V	900 @ 10mA	-65 to 150	SOT-23-3	Active
SZBZX84C30LT1G	onsemi	30	±7%	225	80	50 @ 21V	900 @ 10mA	-65 to 150	SOT-23-3	Active
BZX84-C30,215	NXP Semiconductors	30	±5%	250	80	50 @ 21V	900 @ 10mA	-65 to 150	SOT-23-3	Active
BZX84-C30,235	NXP USA Inc.	30	±5%	250	80	50 @ 21V	900 @ 10mA	-65 to 150	SOT-23-3	Active
BZX84B30-TP	Micro Commercial Co	30	±2%	350	80	100 @ 21V	900 @ 10mA	-55 to 150	SOT-23-3	Active
BZX84C30 BK	Central Semiconductor Corp	30	±5%	500	80	50 @ 21V	900 @ 10mA	-65 to 150	SOT-23-3	Active
BZX84C30 TR TIN/LEAD	Central Semiconductor Corp	30	±5%	500	80	50 @ 21V	900 @ 10mA	-65 to 150	SOT-23-3	Active
BZX84C30-7-F	Diodes Incorporated	30	±7%	300	80	100 @ 21V	900 @ 10mA	-65 to 150	SOT-23-3	Active
BZX84C30W-TP	Micro Commercial Co	30	±7%	200	80	100 @ 21V	1200 @ 100mA	-55 to 150	SOT-323	Active
BZX84C30_R1_00001	Panjit International Inc.	30	±5%	410	80	100 @ 21V	900 @ 10mA	-55 to 150	SOT-23-3	Active

Engineering Selection Recommendations

Primary Substitutes (Highest Compatibility):

The BZX84C30LT1G and SZBZX84C30LT1G from onsemi are direct functional equivalents with identical electrical specifications. Both are active products with ROHS3 compliance. The SZBZX84C30LT1G includes AEC-Q101 automotive qualification, making it suitable for automotive and high-reliability applications. The BZX84C30LT1G is available in Cut Tape & Digi-Reel packaging, while SZBZX84C30LT1G is supplied in Tape & Reel format.

Secondary Substitutes (Acceptable with Considerations):

The BZX84-C30,215 and BZX84-C30,235 from NXP Semiconductors meet all critical parameters with tighter ±5% tolerance and extended temperature range (-65°C to 150°C). Both include AEC-Q101 automotive qualification. Power rating of 250 mW is lower than the original 350 mW but remains adequate for most applications.

The BZX84B30-TP from Micro Commercial Co provides identical 350 mW power rating with superior ±2% tolerance. Operating temperature range matches the original (-55°C to 150°C).

The BZX84C30 BK and BZX84C30 TR TIN/LEAD from Central Semiconductor Corp offer higher 500 mW power dissipation with ±5% tolerance and extended temperature range. Note: RoHS non-compliant status.

The BZX84C30-7-F from Diodes Incorporated provides 300 mW power rating with ±7% tolerance and extended temperature range (-65°C to 150°C), with ROHS3 compliance.

The BZX84C30_R1_00001 from Panjit International Inc. offers 410 mW power rating with ±5% tolerance and ROHS3 compliance.

Package Variant:

The BZX84C30W-TP from Micro Commercial Co uses SOT-323 package instead of SOT-23-3, with reduced 200 mW power rating. This variant is suitable only for applications where the smaller package footprint is required and power dissipation is not a limiting factor.

Compliance Considerations:

For new designs requiring RoHS compliance, select from: BZX84C30LT1G, SZBZX84C30LT1G, BZX84-C30,215, BZX84-C30,235, BZX84C30-7-F, or BZX84C30_R1_00001.

For automotive applications requiring AEC-Q101 qualification, select: SZBZX84C30LT1G, BZX84-C30,215, or BZX84-C30,235.

Frequently Asked Questions (FAQ)

Q: Can I use BZX84C30LT1G as a direct replacement for the obsolete BZX84C30?

A: Yes. The BZX84C30LT1G is functionally equivalent with identical 30 V zener voltage, ±7% tolerance, and 80 Ohm impedance. The primary difference is reduced power rating (225 mW vs. 350 mW) and extended operating temperature range (-65°C to 150°C vs. -55°C to 150°C). Verify that your circuit design does not require the full 350 mW power dissipation capability.

Q: What is the difference between BZX84C30LT1G and SZBZX84C30LT1G?

A: Both parts are electrically identical with 30 V zener voltage, ±7% tolerance, 225 mW power rating, and SOT-23-3 package. The SZBZX84C30LT1G includes AEC-Q101 automotive qualification and is supplied in Tape & Reel packaging. The BZX84C30LT1G is available in Cut Tape & Digi-Reel format. Select SZBZX84C30LT1G for automotive or high-reliability applications.

Q: Why do some substitutes have lower power ratings than the original BZX84C30?

A: The BZX84C30LT1G and BZX84C30-7-F have lower power ratings (225 mW and 300 mW respectively) but maintain identical zener voltage and impedance specifications. These parts are suitable for applications where the circuit does not require continuous operation at maximum power dissipation. Verify your thermal design and power budget before selection.

Q: Are NXP BZX84-C30,215 and BZX84-C30,235 interchangeable?

A: Yes. Both NXP parts are electrically identical with 30 V zener voltage, ±5% tolerance, 250 mW power rating, and SOT-23-3 package. The primary difference is packaging format: BZX84-C30,215 is supplied in standard packaging, while BZX84-C30,235 is supplied in bulk. Both include AEC-Q101 automotive qualification.

Q: Can I use BZX84B30-TP instead of BZX84C30?

A: Yes. The BZX84B30-TP provides superior ±2% tolerance compared to the original ±7%, with identical 30 V zener voltage, 350 mW power rating, and SOT-23-3 package. The tighter tolerance makes this part suitable for applications requiring more precise voltage regulation. Operating temperature range is identical (-55°C to 150°C).

Q: What is the significance of the SOT-323 package variant BZX84C30W-TP?

A: The BZX84C30W-TP uses a smaller SOT-323 package instead of SOT-23-3, reducing board footprint. However, power rating is reduced to 200 mW. This variant is suitable only for space-constrained designs where power dissipation does not exceed 200 mW. Verify PCB layout compatibility before selection.

Q: Which substitute offers the highest power dissipation capability?

A: The BZX84C30 BK and BZX84C30 TR TIN/LEAD from Central Semiconductor Corp both offer 500 mW power rating, the highest among all substitutes. These parts are suitable for high-power applications. Note that these parts are RoHS non-compliant.

Q: Are all substitutes available in SOT-23-3 package?

A: No. The BZX84C30W-TP uses SOT-323 package. All other substitutes use SOT-23-3 or compatible TO-236-3/SC-59 packages. Verify package compatibility with your PCB design before selection.

Q: What is the difference between ±7%, ±5%, and ±2% tolerance specifications?

A: Tolerance indicates the allowable deviation of the zener voltage from the nominal 30 V specification. ±7% allows ±2.1 V deviation (27.9 V to 32.1 V), ±5% allows ±1.5 V deviation (28.5 V to 31.5 V), and ±2% allows ±0.6 V deviation (29.4 V to 30.6 V). Tighter tolerance provides more precise voltage regulation. Select based on your circuit's voltage regulation requirements.

Q: Do all substitutes meet RoHS compliance requirements?

A: No. The BZX84C30 BK and BZX84C30 TR TIN/LEAD are RoHS non-compliant. All other substitutes are ROHS3 compliant. For applications requiring RoHS compliance, exclude these two parts from consideration.

Q: Which substitutes include automotive qualification?

A: The SZBZX84C30LT1G, BZX84-C30,215, and BZX84-C30,235 include AEC-Q101 automotive qualification. These parts are suitable for automotive and high-reliability applications requiring formal qualification documentation.

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