SD1726 RF Transistor NPN 55V Equivalent & Substitute Parts

Part Overview

The SD1726 is an RF Transistor NPN rated at 55V maximum collector-emitter breakdown voltage, designed for surface mount applications in the M174 package. This component is classified as obsolete, necessitating identification of functionally equivalent alternatives for ongoing design requirements and production continuity. The part delivers 318W maximum power dissipation with a 20A maximum collector current and 14dB gain, suitable for RF applications requiring high power handling in compact form factors.

Substiute Parts

SD1726

STMicroelectronicsIn Stock: 1989SD1726 Datasheet

Current PartRFQ

SD2931-10W

STMicroelectronicsIn Stock: 2479SD2931-10W Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the obsolete SD1726 is based on the following critical parameters that define functional equivalence:

Package Compatibility: Both the main part and substitute must use the M174 surface mount package to ensure mechanical and thermal compatibility with existing PCB layouts.

Voltage Rating: The substitute must support the operating voltage envelope. The SD1726 specifies 55V maximum collector-emitter breakdown; substitutes must meet or exceed this rating to prevent overstress conditions.

Current Handling: Maximum collector current of 20A establishes the current delivery requirement. Substitutes must support this current level or higher.

Power Dissipation: The 318W maximum power rating defines the thermal management capability required. Substitutes must handle equivalent or greater power levels.

Gain Specification: The 14dB gain parameter establishes the signal amplification requirement for RF applications.

Compliance Requirements: RoHS3 compliance and REACH unaffected status ensure regulatory alignment with modern manufacturing standards.

The SD2931-10W substitute is identified as a functionally equivalent alternative based on shared M174 packaging, compatible voltage ratings (50V test voltage with 125V rated voltage), matching 20A current capability, and equivalent gain specification (15dB). Both components maintain ROHS3 compliance and REACH unaffected status.

Parameter Comparison

Engineering Selection Recommendations

Primary Consideration - Product Status: The SD1726 is classified as obsolete, making the SD2931-10W the appropriate selection for new designs and production continuity. The SD2931-10W maintains active product status with STMicroelectronics, ensuring ongoing availability and technical support.

Compliance Alignment: Both components maintain ROHS3 compliance and REACH unaffected status, satisfying regulatory requirements for modern manufacturing environments. No compliance barriers exist for substitution.

Package and Thermal Management: Both parts utilize the M174 surface mount package, ensuring direct mechanical compatibility with existing PCB designs. Thermal characteristics remain consistent with the shared package form factor.

Electrical Performance: The SD2931-10W delivers equivalent current handling (20A) and superior gain specification (15dB versus 14dB). The substitute's 150W power output is lower than the main part's 318W rating; this difference reflects the distinct device technologies (MOSFET versus BJT) and must be evaluated against specific application power requirements.

Technology Transition: The substitution represents a transition from bipolar junction transistor (BJT) technology to metal-oxide-semiconductor field-effect transistor (MOSFET) technology. This transition maintains functional RF performance while leveraging active product availability.

Frequently Asked Questions (FAQ)

Q: Can the SD2931-10W directly replace the SD1726 in existing designs?

A: Direct replacement is possible from a package and mounting perspective, as both components use the M174 surface mount package. However, the transition from NPN BJT to N-Channel MOSFET technology introduces operational differences that require circuit evaluation. The SD2931-10W's lower power output (150W versus 318W) must be assessed against application requirements.

Q: What are the key differences between the SD1726 and SD2931-10W?

A: The primary differences are device technology (BJT versus MOSFET), power output capability (318W versus 150W), and product status (obsolete versus active). Both components share the M174 package, 20A current rating, and comparable gain specifications (14dB versus 15dB). Voltage ratings differ slightly (55V breakdown versus 50V test / 125V rated).

Q: Are there compliance concerns with substituting the SD2931-10W?

A: No compliance concerns exist. Both components maintain ROHS3 compliance and REACH unaffected status, satisfying regulatory requirements for modern manufacturing and distribution.

Q: Does the M174 package ensure thermal compatibility?

A: Yes. Both components use the identical M174 surface mount package, ensuring thermal interface compatibility with existing PCB designs. Thermal performance depends on PCB layout and thermal management design rather than package selection.

Q: What should be evaluated before implementing the SD2931-10W substitution?

A: Circuit-level evaluation is required to confirm that the SD2931-10W's 150W power output meets application requirements. The MOSFET technology transition may affect impedance matching, biasing networks, and frequency response characteristics compared to the original BJT design. Electrical performance validation is necessary for RF applications.

Q: Is the SD2931-10W available in the same packaging format?

A: Yes. The SD2931-10W is supplied in M174 package format with surface mount mounting type, identical to the SD1726. Packaging compatibility is confirmed.