CZRT5231B-G Zener Diode 5.1V 300mW SOT-23-3 Equivalent & Substitute Parts

Part Overview

The CZRT5231B-G is an active-status surface mount Zener diode manufactured by Comchip Technology, rated at 5.1 V nominal with 300 mW maximum power dissipation in SOT-23-3 packaging. This component is designed for voltage regulation and protection applications in electronic circuits. Substitute parts are identified when equivalent electrical performance and mechanical compatibility are required due to inventory constraints, manufacturing discontinuation, or design flexibility needs.

Key Parameters

Parameter	Value	Unit
Voltage - Zener (Nom)	5.1	V
Tolerance	±5%	—
Power - Max	300	mW
Impedance (Max)	17	Ohms
Current - Reverse Leakage @ Vr	5	µA @ 2 V
Voltage - Forward (Vf) (Max) @ If	900	mV @ 10 mA
Operating Temperature Range	-65 to 150	°C
Mounting Type	Surface Mount	—
Package / Case	SOT-23-3	—
RoHS Status	ROHS3 Compliant	—
Moisture Sensitivity Level	1 (Unlimited)	—

Substitute Part Grouping Explanation

Substitution of the CZRT5231B-G is determined by strict alignment of the following critical parameters:

Primary Substitution Criteria:

Zener voltage: 5.1 V nominal
Package type: SOT-23-3 (TO-236-3, SC-59)
Mounting: Surface Mount
Operating temperature range: -65°C to 150°C minimum
RoHS3 compliance and MSL 1 rating

Secondary Compatibility Factors:

Tolerance: ±5% or tighter acceptable
Power rating: 300 mW minimum
Impedance: 17 Ohms or lower preferred for regulation performance
Reverse leakage: 5 µA @ 2 V or lower
Forward voltage: 900 mV @ 10 mA maximum

Substitute parts are grouped into three categories based on electrical equivalence:

Category 1 - Direct Parametric Equivalents (Identical Specifications): Parts with matching impedance (17 Ohms), tolerance (±5%), and all electrical characteristics. These provide direct pin-for-pin replacement without circuit performance variation.

Category 2 - Enhanced Specification Equivalents (Improved Performance): Parts with tighter tolerance (±2% to ±3%), lower impedance (60 Ohms or 17 Ohms), or higher power rating (350 mW). These offer superior regulation characteristics and are suitable for applications requiring tighter voltage control.

Category 3 - Functional Equivalents (Acceptable Variation): Parts with looser tolerance (±6%) or different impedance characteristics but maintaining core 5.1 V regulation function. These are suitable for general-purpose applications where voltage tolerance is not critical.

Parameter Comparison

Part Number	Manufacturer	Vz (Nom)	Tolerance	Power Max	Zzt (Max)	Ir @ Vr	Vf (Max)	Temp Range	Package	AEC-Q101
CZRT5231B-G	Comchip	5.1 V	±5%	300 mW	17 Ω	5 µA @ 2V	900 mV @ 10mA	-65 to 150°C	SOT-23-3	—
CZRT5231B-HF	Comchip	5.1 V	±5%	300 mW	17 Ω	5 µA @ 2V	900 mV @ 10mA	-65 to 150°C	SOT-23-3	—
BZX84B5V1-7-F	Diodes Inc	5.1 V	±2%	300 mW	60 Ω	2 µA @ 2V	900 mV @ 10mA	-65 to 150°C	SOT-23-3	Yes
BZX84B5V1Q-7-F	Diodes Inc	5.1 V	±2%	300 mW	60 Ω	2 µA @ 2V	900 mV @ 10mA	-65 to 150°C	SOT-23-3	Yes
BZX84C5V1-7-F	Diodes Inc	5.1 V	±6%	300 mW	60 Ω	2 µA @ 2V	900 mV @ 10mA	-65 to 150°C	SOT-23-3	Yes
MMBZ5231B-7-F	Diodes Inc	5.1 V	±5%	350 mW	17 Ω	5 µA @ 2V	900 mV @ 10mA	-65 to 150°C	SOT-23-3	—
MMBZ5231B-TP	Micro Commercial	5.1 V	±5%	350 mW	17 Ω	5 µA @ 2V	900 mV @ 10mA	-55 to 150°C	SOT-23-3	—
DDZX5V1B-7	Diodes Inc	5.1 V	±3%	300 mW	17 Ω	5 µA @ 1.5V	900 mV @ 10mA	-65 to 150°C	SOT-23-3	—
DDZX5V1BQ-7	Diodes Inc	5.1 V	±2%	300 mW	17 Ω	5 µA @ 1.5V	900 mV @ 10mA	-65 to 150°C	SOT-23-3	Yes

Engineering Selection Recommendations

Direct Replacement (No Circuit Modification Required):

CZRT5231B-HF is the primary direct substitute, offering identical electrical specifications and packaging. Both parts are manufactured by Comchip Technology with matching impedance (17 Ohms) and tolerance (±5%), ensuring equivalent circuit performance.

Enhanced Performance Substitutes (Improved Regulation):

DDZX5V1B-7 and DDZX5V1BQ-7 provide tighter tolerance (±3% and ±2% respectively) with maintained 17 Ohm impedance, suitable for applications requiring improved voltage regulation accuracy. DDZX5V1BQ-7 includes AEC-Q101 automotive qualification.

BZX84B5V1-7-F and BZX84B5V1Q-7-F offer ±2% tolerance with AEC-Q101 qualification. Higher impedance (60 Ohms) results in different regulation characteristics; verify circuit compatibility before substitution.

Higher Power Rating Alternatives:

MMBZ5231B-7-F and MMBZ5231B-TP provide 350 mW power rating with 17 Ohm impedance and ±5% tolerance, suitable for applications requiring increased thermal margin. MMBZ5231B-TP minimum operating temperature is -55°C (versus -65°C for primary part).

General Purpose Applications:

BZX84C5V1-7-F offers ±6% tolerance with AEC-Q101 qualification and high inventory availability (155,100 units). Suitable for non-critical voltage regulation where tolerance variation is acceptable.

All substitute parts maintain SOT-23-3 packaging, RoHS3 compliance, and MSL 1 rating, ensuring compatibility with standard surface mount assembly processes.

Frequently Asked Questions (FAQ)

Q: Can CZRT5231B-HF replace CZRT5231B-G in all applications?

A: Yes. CZRT5231B-HF is a direct parametric equivalent with identical Zener voltage (5.1 V), tolerance (±5%), power rating (300 mW), impedance (17 Ohms), and operating temperature range (-65°C to 150°C). Pin configuration and package (SOT-23-3) are identical, requiring no circuit modification.

Q: What is the difference between 17 Ohm and 60 Ohm impedance in Zener diodes?

A: Impedance (Zzt) affects voltage regulation performance. Lower impedance (17 Ohms) provides better voltage stability across load current variations. Higher impedance (60 Ohms) results in greater voltage variation but is acceptable for general-purpose applications. Verify circuit requirements before substituting between these values.

Q: Are BZX84 series parts suitable replacements for CZRT5231B-G?

A: BZX84B5V1-7-F, BZX84B5V1Q-7-F, and BZX84C5V1-7-F are functionally compatible with identical 5.1 V Zener voltage, 300 mW power rating, and SOT-23-3 packaging. However, they feature 60 Ohm impedance versus 17 Ohms in the original part. BZX84 series parts include AEC-Q101 automotive qualification. Verify impedance compatibility with your circuit design.

Q: What does AEC-Q101 qualification mean?

A: AEC-Q101 is an automotive electronics qualification standard. Parts bearing this qualification (BZX84B5V1-7-F, BZX84B5V1Q-7-F, BZX84C5V1-7-F, DDZX5V1BQ-7) have undergone rigorous reliability testing for automotive applications. These parts are suitable for both automotive and industrial applications requiring higher reliability assurance.

Q: Can I use MMBZ5231B-7-F (350 mW) instead of CZRT5231B-G (300 mW)?

A: Yes. MMBZ5231B-7-F provides higher power rating (350 mW) with identical Zener voltage (5.1 V), tolerance (±5%), impedance (17 Ohms), and operating temperature range. The higher power rating provides additional thermal margin and is a direct upgrade. No circuit modification required.

Q: What is the difference between Tape & Reel (TR) and Cut Tape (CT) packaging?

A: Tape & Reel (TR) packaging is supplied on continuous reels for automated assembly lines. Cut Tape (CT) is supplied in smaller quantities on tape segments. Both contain identical components; packaging format depends on production volume and assembly equipment. Electrical performance is identical.

Q: Is MMBZ5231B-TP compatible with CZRT5231B-G?

A: MMBZ5231B-TP is functionally compatible with identical 5.1 V Zener voltage, ±5% tolerance, 350 mW power rating, and 17 Ohm impedance. However, minimum operating temperature is -55°C (versus -65°C for CZRT5231B-G). Verify your application's minimum temperature requirement before substitution.

Q: What does ±5%, ±3%, and ±2% tolerance mean for Zener voltage?

A: Tolerance specifies the acceptable voltage variation from the nominal 5.1 V rating. ±5% tolerance allows 4.845 V to 5.355 V; ±3% allows 4.947 V to 5.253 V; ±2% allows 4.998 V to 5.202 V. Tighter tolerance (lower percentage) provides more precise voltage regulation. Select based on your circuit's voltage tolerance requirements.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All listed substitute parts are RoHS3 compliant and carry MSL 1 (Unlimited) moisture sensitivity rating, matching the original CZRT5231B-G specifications. All parts are suitable for standard surface mount assembly and storage without special moisture control requirements.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message