CZRF52C18-HF Zener Diode 18V 200mW Equivalent & Substitute Parts

Part Overview

The CZRF52C18-HF is an 18V Zener diode manufactured by Comchip Technology, rated for 200mW power dissipation in a surface mount 1005/SOD-323F package. This component is classified as Active and maintains full RoHS3 compliance with unlimited moisture sensitivity rating (MSL 1). The part is suitable for voltage regulation and protection circuits requiring precise 18V reference voltage with ±5% tolerance. Substitute parts are identified when equivalent electrical performance can be achieved within the allowed parameter ranges for this Zener diode category, particularly when higher power ratings or improved tolerance specifications are required for specific application demands.

Substiute Parts

CZRF52C18-HF

Comchip TechnologyIn Stock: 1074CZRF52C18-HF Datasheet

Current PartRFQ

BZX84J-B18,115

Nexperia USA Inc.In Stock: 6765BZX84J-B18,115 Datasheet

MFR RecommendedRFQ

PLZ18C-G3/H

Vishay General Semiconductor - Diodes DivisionIn Stock: 2100PLZ18C-G3/H Datasheet

MFR RecommendedRFQ

TDZ18J,115

Nexperia USA Inc.In Stock: 4238TDZ18J,115 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the CZRF52C18-HF is determined by strict adherence to the following electrical and mechanical criteria:

Primary Substitution Criteria:

• Zener voltage must equal 18V nominal
• Package must be surface mount compatible (SOD-323F or equivalent mechanical footprint)
• Operating temperature range must encompass or exceed the application requirement
• RoHS3 compliance mandatory
• Impedance (Zzt) maximum 20 Ohms or lower

Secondary Compatibility Factors:

• Power rating may exceed 200mW (higher ratings provide design margin)
• Tolerance may be tighter than ±5% (improved voltage accuracy)
• Reverse leakage current specifications may be lower (improved performance)
• Forward voltage characteristics must be compatible with circuit design

The three substitute parts listed (BZX84J-B18,115; PLZ18C-G3/H; TDZ18J,115) meet all primary criteria and offer enhanced electrical characteristics within the allowed parameter ranges for 18V Zener diodes in surface mount packages.

Parameter Comparison

Engineering Selection Recommendations

BZX84J-B18,115 (Nexperia USA Inc.): This substitute offers 550mW power rating with ±2% tolerance and AEC-Q101 automotive qualification. The extended operating temperature range (-65 to 150°C) provides additional thermal margin. Impedance specification matches the original at 20 Ohms maximum. This part is suitable for applications requiring automotive-grade reliability and higher power dissipation capability within the same SOD-323F package footprint.

PLZ18C-G3/H (Vishay General Semiconductor): This substitute provides 500mW power rating with ±3% tolerance in a DO-219AC (microSMF) package. The impedance specification is 23 Ohms maximum, which remains within acceptable substitution parameters. Forward voltage at 10mA (800mV) matches the original specification more closely than other alternatives. This part is suitable for applications where package footprint compatibility with DO-219AC is acceptable and moderate power dissipation improvement is required.

TDZ18J,115 (Nexperia USA Inc.): This substitute delivers 500mW power rating with ±2% tolerance and AEC-Q101 automotive qualification. Operating temperature range extends to 150°C maximum. Impedance specification matches the original at 20 Ohms maximum. This part is suitable for automotive applications requiring improved voltage tolerance and higher power handling in the same SOD-323F package footprint as the original.

All three substitutes maintain RoHS3 compliance, MSL 1 rating, and 18V nominal Zener voltage. Selection depends on specific application requirements for power dissipation, tolerance accuracy, temperature range, and package compatibility.

Frequently Asked Questions (FAQ)

Q: Can BZX84J-B18,115 be used as a direct replacement for CZRF52C18-HF?

A: Yes, within the constraints of circuit design. Both parts share the same 18V nominal Zener voltage, 20 Ohms maximum impedance, and SOD-323F package. The BZX84J-B18,115 provides higher power rating (550mW vs 200mW), tighter tolerance (±2% vs ±5%), and extended temperature range (-65 to 150°C vs -55 to 125°C). Verify that the circuit design accommodates the different forward voltage characteristics at the specified current levels.

Q: What is the key difference between PLZ18C-G3/H and the other substitutes?

A: The PLZ18C-G3/H uses a DO-219AC (microSMF) package instead of SOD-323F. While the electrical specifications are compatible (18V, 500mW, ±3% tolerance), the physical package footprint differs. This substitute is suitable only if the PCB layout can accommodate DO-219AC package dimensions. The impedance specification is 23 Ohms maximum, slightly higher than the original 20 Ohms.

Q: Are TDZ18J,115 and BZX84J-B18,115 interchangeable?

A: Both parts share identical electrical core specifications: 18V nominal voltage, 20 Ohms maximum impedance, ±2% tolerance, 500-550mW power rating, SOD-323F package, and AEC-Q101 automotive qualification. The primary difference is power rating (550mW vs 500mW). They are functionally interchangeable in most applications. Verify manufacturer-specific parametric data for forward voltage characteristics if the circuit operates at specific current levels.

Q: Does the CZRF52C18-HF require automotive qualification?

A: The CZRF52C18-HF does not carry automotive qualification. If the application requires AEC-Q101 compliance, substitute with BZX84J-B18,115 or TDZ18J,115, both of which are automotive-qualified Zener diodes with identical 18V specifications.

Q: Can I use a substitute with higher power rating in a space-constrained design?

A: All substitute parts (BZX84J-B18,115, PLZ18C-G3/H, TDZ18J,115) are available in surface mount packages compatible with the original 1005/SOD-323F footprint or equivalent mechanical dimensions. Higher power rating does not increase package size. Verify PCB layout compatibility with the specific package designation before substitution.

Q: What is the significance of the ±2% tolerance in BZX84J-B18,115 and TDZ18J,115?

A: The ±2% tolerance provides tighter voltage regulation compared to the original ±5% specification. This means the actual Zener voltage will remain closer to the nominal 18V across the specified operating range. Use this specification when the circuit design requires improved voltage accuracy for reference or protection functions.

Q: Is reverse leakage current a critical factor in selecting a substitute?

A: Reverse leakage current becomes significant in low-current applications or when circuit design requires minimal standby current. The CZRF52C18-HF specifies 100nA @ 8.5V, while BZX84J-B18,115 and TDZ18J,115 specify 50nA @ 12.6V. PLZ18C-G3/H specifies 200nA @ 13V. Select based on the specific circuit requirement for leakage current performance.