HER155-AP Equivalent & Substitute Parts

Part Overview

The HER155-AP is a general-purpose rectifier diode manufactured by Micro Commercial Co, rated for 400 V DC reverse voltage and 1.5 A average rectified current in a DO-15 through-hole package. This component is classified as obsolete, making identification of suitable substitute parts necessary for ongoing design support and procurement continuity. The fast recovery characteristics (≤500 ns) and compact axial package make this diode suitable for standard rectification applications requiring moderate current handling.

Substiute Parts

HER155-AP

Micro Commercial CoIn Stock: 727HER155-AP Datasheet

Current PartRFQ

HER205G-AP

Micro Commercial CoIn Stock: 1150HER205G-AP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the HER155-AP is determined by electrical and mechanical compatibility across the following critical parameters:

Voltage Rating: The substitute part must maintain the 400 V DC reverse voltage specification to ensure safe operation in the intended circuit.

Current Rating: The substitute part current rating must equal or exceed the 1.5 A average rectified current requirement. Parts with higher current ratings (such as 2 A) are acceptable as they provide equivalent or superior performance within the same voltage class.

Forward Voltage Characteristics: Forward voltage drop must remain consistent to preserve circuit performance and power dissipation calculations.

Recovery Speed: Fast recovery characteristics (≤500 ns) must be maintained to ensure switching performance in rectification applications.

Package and Mounting: The DO-15 axial through-hole package is mandatory for mechanical and electrical compatibility with existing PCB layouts.

Temperature Range: Operating temperature specifications must support the application's thermal environment.

Compliance Standards: RoHS3 compliance and MSL rating must be maintained for regulatory and manufacturing process compatibility.

The HER205G-AP qualifies as a direct substitute based on matching all critical parameters while providing enhanced current capacity (2 A versus 1.5 A).

Parameter Comparison

Engineering Selection Recommendations

The HER205G-AP is the qualified substitute for the HER155-AP based on the following engineering criteria:

Electrical Equivalence: Both parts share identical voltage ratings (400 V), forward voltage characteristics (1.3 V), recovery speed (50 ns), and leakage current specifications (5 µA @ 400 V). The HER205G-AP provides a higher current rating (2 A) while maintaining all other electrical parameters, making it suitable for applications requiring the original 1.5 A specification.

Mechanical Compatibility: Both parts use the DO-15 axial through-hole package, ensuring direct PCB layout compatibility without redesign.

Compliance and Availability: The HER205G-AP holds active product status with ROHS3 compliance and unlimited moisture sensitivity rating, matching the regulatory requirements of the obsolete HER155-AP. Current inventory availability (1131 pieces) supports procurement continuity.

Temperature Performance: The HER205G-AP extends the operating temperature range to 150°C, providing additional thermal margin compared to the HER155-AP specification of 125°C.

Selection of the HER205G-AP eliminates obsolescence risk while maintaining full electrical and mechanical compatibility with existing designs.

Frequently Asked Questions (FAQ)

Q: Can the HER205G-AP directly replace the HER155-AP in existing designs?

A: Yes. The HER205G-AP is electrically and mechanically compatible with the HER155-AP. Both parts share identical voltage ratings, forward voltage characteristics, recovery speed, and package configuration. The higher current rating of the HER205G-AP (2 A versus 1.5 A) does not create compatibility issues and provides additional design margin.

Q: What is the primary reason for substitution?

A: The HER155-AP is classified as obsolete. The HER205G-AP is an active product from the same manufacturer with equivalent electrical specifications and superior availability, making it the appropriate substitute for procurement and design continuity.

Q: Are the package dimensions identical between HER155-AP and HER205G-AP?

A: Both parts use the DO-15 axial through-hole package (DO-204AC designation). Package dimensions and pin configuration are identical, allowing direct PCB substitution without layout modifications.

Q: How do the current ratings affect circuit performance?

A: The HER205G-AP is rated for 2 A average rectified current compared to the HER155-AP specification of 1.5 A. In applications requiring 1.5 A, the HER205G-AP operates within its rated capacity with additional current margin. Forward voltage drop remains constant at 1.3 V, preserving power dissipation calculations.

Q: Are compliance certifications maintained with the substitute part?

A: Yes. The HER205G-AP maintains ROHS3 compliance and MSL rating 1 (Unlimited), matching the regulatory requirements of the HER155-AP. Both parts are suitable for applications requiring environmental and manufacturing process compliance.

Q: What is the difference in operating temperature range?

A: The HER155-AP operates from -55°C to 125°C junction temperature. The HER205G-AP extends the upper limit to 150°C, providing 25°C additional thermal margin. This does not affect substitution in applications operating within the original -55°C to 125°C range.

Q: Are there any electrical performance differences in rectification speed?

A: No. Both parts share identical reverse recovery time (50 ns) and fast recovery characteristics (≤500 ns for currents >200 mA). Switching performance and rectification speed are equivalent.