IRF644NSTRR Equivalent & Substitute Parts

Part Overview

The IRF644NSTRR is an N-Channel MOSFET manufactured by Vishay Siliconix, rated for 250V drain-to-source voltage and 14A continuous drain current in a Surface Mount TO-263 (D2PAK) package. This device is classified as obsolete, necessitating identification of active equivalent components for new designs and ongoing production requirements. The part delivers 150W maximum power dissipation and operates across a temperature range of -55°C to 175°C (TJ).

Substiute Parts

IRF644NSTRR

Vishay SiliconixIn Stock: 954IRF644NSTRR Datasheet

Current PartRFQ

RCJ120N25TL

Rohm SemiconductorIn Stock: 1828RCJ120N25TL Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the IRF644NSTRR is determined by electrical and mechanical compatibility across the following critical parameters:

Voltage Rating: Both the main part and substitute must maintain a Drain to Source Voltage (Vdss) rating of 250V to ensure safe operation in the target application circuit.

Current Capability: The substitute part must support continuous drain current (Id) at or above the application requirement. The IRF644NSTRR specifies 14A (Tc); substitute parts with lower current ratings require circuit-level verification of thermal and current distribution.

On-State Resistance (Rds On): This parameter directly affects power dissipation and thermal performance. Substitute parts with comparable or lower Rds On values maintain equivalent or improved efficiency characteristics.

Gate Charge (Qg): Lower gate charge values reduce switching losses and driver circuit stress, making parts with reduced Qg favorable for high-frequency switching applications.

Package Compatibility: The TO-263 (D2PAK) Surface Mount package defines the mechanical footprint and thermal interface. Substitute parts must use identical or compatible package designations to ensure PCB layout compatibility.

Product Status and Compliance: Active product status and RoHS compliance certification ensure long-term availability and regulatory alignment for new designs.

Parameter Comparison

Engineering Selection Recommendations

RCJ120N25TL as Primary Substitute

The RCJ120N25TL from Rohm Semiconductor qualifies as a functional substitute for the IRF644NSTRR based on the following criteria:

Voltage Compatibility: Both parts maintain identical 250V Drain to Source Voltage ratings, ensuring direct electrical compatibility in circuits designed for the IRF644NSTRR.

Current Derating: The RCJ120N25TL specifies 12A continuous drain current compared to the IRF644NSTRR's 14A rating. Applications operating at or below 12A (Tc) experience no functional limitation. Circuits requiring the full 14A capability must implement current distribution or thermal management adjustments.

On-State Resistance: The RCJ120N25TL exhibits 235 mOhm Rds On (Max) at 6A, 10V, compared to 240 mOhm at 8.4A, 10V for the IRF644NSTRR. This represents equivalent performance within measurement tolerance bands.

Gate Charge Reduction: The RCJ120N25TL demonstrates 35 nC gate charge versus 54 nC for the IRF644NSTRR, reducing switching losses and driver circuit stress by approximately 35%.

Product Status and Compliance: The RCJ120N25TL carries Active product status and ROHS3 compliance certification, ensuring long-term availability and regulatory alignment for new production designs. The IRF644NSTRR's Obsolete status and RoHS non-compliance status necessitate transition to active alternatives.

Package Compatibility: Both parts use TO-263 (D2PAK) Surface Mount packaging, enabling direct PCB layout compatibility without redesign.

Temperature Operating Range Consideration: The RCJ120N25TL specifies a maximum junction temperature of 150°C, compared to 175°C for the IRF644NSTRR. Applications operating continuously above 150°C (TJ) require thermal analysis to confirm the substitute part's suitability.

Frequently Asked Questions (FAQ)

Q: Can the RCJ120N25TL directly replace the IRF644NSTRR without circuit modification?

A: Direct replacement is possible for applications operating at or below 12A continuous drain current. The identical 250V voltage rating and TO-263 package ensure electrical and mechanical compatibility. Applications requiring the full 14A capability of the IRF644NSTRR must evaluate thermal performance and current distribution in the target circuit.

Q: What is the significance of the gate charge difference between these parts?

A: The RCJ120N25TL's 35 nC gate charge is approximately 35% lower than the IRF644NSTRR's 54 nC. Lower gate charge reduces the energy required to switch the transistor, decreasing switching losses and reducing stress on the gate driver circuit. This characteristic is beneficial in high-frequency switching applications.

Q: Are there package compatibility concerns when substituting these parts?

A: Both the IRF644NSTRR and RCJ120N25TL use the TO-263 (D2PAK) Surface Mount package with identical pinout and footprint. No PCB layout modifications are required for mechanical or electrical connection.

Q: Why is the RCJ120N25TL's maximum power dissipation lower than the IRF644NSTRR?

A: The RCJ120N25TL specifies 107W (Tc) maximum power dissipation compared to 150W (Tc) for the IRF644NSTRR. This difference reflects the lower continuous current rating (12A versus 14A) and different thermal characteristics of the Rohm device. Applications must verify that thermal dissipation requirements do not exceed 107W (Tc) for the substitute part.

Q: What compliance advantages does the RCJ120N25TL offer?

A: The RCJ120N25TL carries ROHS3 compliance certification and Active product status, ensuring regulatory alignment and long-term component availability. The IRF644NSTRR is classified as Obsolete and RoHS non-compliant, creating supply chain and regulatory risks for new production designs.

Q: How does the input capacitance difference affect circuit performance?

A: The RCJ120N25TL exhibits 1800 pF input capacitance (Ciss) at 25V, compared to 1060 pF for the IRF644NSTRR. Higher input capacitance increases the charge required to drive the gate and may increase switching times in circuits with limited gate driver current. Gate driver circuits must be evaluated to confirm adequate current sourcing capability.

Q: Is the RCJ120N25TL suitable for applications operating above 150°C junction temperature?

A: The RCJ120N25TL specifies a maximum junction temperature of 150°C, compared to 175°C for the IRF644NSTRR. Applications requiring continuous operation above 150°C (TJ) must perform thermal analysis to confirm the substitute part remains within safe operating limits or implement additional thermal management measures.