HD1520FX Equivalent & Substitute Parts

Part Overview

The HD1520FX is an NPN bipolar junction transistor manufactured by STMicroelectronics, rated for 700 V collector-emitter breakdown voltage and 15 A maximum collector current in an ISOWATT-218FX through-hole package. This device is classified as obsolete, necessitating identification of functionally equivalent alternatives for ongoing production support and design continuity.

Substiute Parts

HD1520FX

STMicroelectronicsIn Stock: 2246HD1520FX Datasheet

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HD1750FX

STMicroelectronicsIn Stock: 58185HD1750FX Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the HD1520FX is determined by electrical and mechanical compatibility within the following criteria:

Electrical Compatibility Requirements:

• Transistor type must be NPN
• Collector-emitter breakdown voltage must equal or exceed 700 V
• Maximum collector current must equal or exceed 15 A
• Maximum power dissipation must equal or exceed 64 W
• Operating temperature rating must be 150°C or higher
• Saturation voltage characteristics must support the application's switching requirements

Mechanical Compatibility Requirements:

• Package type must be ISOWATT-218FX
• Mounting type must be through-hole
• Pin configuration must be identical

The HD1750FX meets all electrical and mechanical substitution criteria, with enhanced ratings in voltage (800 V), current (24 A), and power (75 W) capabilities.

Parameter Comparison

Engineering Selection Recommendations

HD1520FX Status: Obsolete. This part is no longer recommended for new designs and faces supply discontinuation.

HD1750FX as Primary Substitute: The HD1750FX is the direct functional equivalent for the HD1520FX. Both devices share identical package geometry (ISOWATT-218FX), mounting type (through-hole), and thermal rating (150°C). The HD1750FX provides superior electrical performance with higher voltage (800 V vs. 700 V), current (24 A vs. 15 A), and power (75 W vs. 64 W) ratings. Both parts maintain ROHS3 compliance and REACH unaffected status.

Product Status Consideration: The HD1750FX carries a "Not For New Designs" status, indicating it is also in end-of-life phase. However, it maintains significantly higher inventory availability (58,088 pcs vs. 2,200 pcs for the HD1520FX) and remains the specified substitute for the obsolete HD1520FX.

Compliance: Both parts satisfy RoHS3 and REACH regulatory requirements for electronic component applications.

Frequently Asked Questions (FAQ)

Q: Can the HD1750FX directly replace the HD1520FX in existing designs?

A: Yes. The HD1750FX is mechanically and electrically compatible with the HD1520FX. Both use the ISOWATT-218FX package with identical through-hole mounting. The HD1750FX's higher voltage, current, and power ratings provide equal or superior performance in all specified operating conditions.

Q: What are the key differences between HD1520FX and HD1750FX?

A: The HD1750FX provides enhanced electrical specifications: 800 V breakdown voltage (vs. 700 V), 24 A maximum collector current (vs. 15 A), and 75 W power dissipation (vs. 64 W). DC current gain is also higher at 6.5 (vs. 5.5). Saturation voltage characteristics differ slightly at higher current levels.

Q: Are there any package or pinout differences?

A: No. Both the HD1520FX and HD1750FX use the ISOWATT-218FX package with identical through-hole mounting configuration. Direct PCB substitution is possible without layout modifications.

Q: Do both parts meet current regulatory requirements?

A: Yes. Both the HD1520FX and HD1750FX are ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory standards for electronic components.

Q: Why is the HD1750FX marked "Not For New Designs" if it is the recommended substitute?

A: The "Not For New Designs" status indicates the HD1750FX is in end-of-life phase. However, it remains the specified substitute for the obsolete HD1520FX and is available in significantly higher quantities. For new designs, consultation with STMicroelectronics for current-generation alternatives is recommended.

Q: What is the thermal operating range for both devices?

A: Both the HD1520FX and HD1750FX are rated for a maximum junction temperature (TJ) of 150°C. This identical thermal specification ensures equivalent thermal performance in applications.