IRLR3705Z N-Channel MOSFET Equivalent & Substitute Parts

Part Overview

The IRLR3705Z is an N-Channel MOSFET manufactured by Infineon Technologies, rated for 55V drain-to-source voltage with 42A continuous drain current at 25°C. This device is housed in a TO-252-3 (DPAK) surface mount package and is classified as obsolete. Due to its obsolete status, identifying functionally equivalent substitute parts is necessary for ongoing design support, production continuity, and component sourcing. The substitutes listed maintain electrical compatibility within the specified parameter ranges while offering improved availability or enhanced performance characteristics.

Substiute Parts

IRLR3705Z

Infineon TechnologiesIn Stock: 1529IRLR3705Z Datasheet

Current PartRFQ

BUK7212-55B,118

Nexperia USA Inc.In Stock: 7283BUK7212-55B,118 Datasheet

MFR RecommendedRFQ

DMTH6010SK3Q-13

Diodes IncorporatedIn Stock: 3506DMTH6010SK3Q-13 Datasheet

MFR RecommendedRFQ

STD60NF55LT4

STMicroelectronicsIn Stock: 17844STD60NF55LT4 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the IRLR3705Z is determined by the following critical parameters:

Mandatory Compatibility Criteria:

• Drain-to-Source Voltage (Vdss): Must equal or exceed 55V
• Package Type: Must be TO-252-3 (DPAK) surface mount
• FET Type: Must be N-Channel
• Technology: Must be MOSFET (Metal Oxide)

Performance Compatibility Criteria:

• Continuous Drain Current (Id): Must meet or exceed 42A at 25°C
• On-State Resistance (Rds On): Must not exceed 8mOhm at rated current and gate voltage
• Gate Threshold Voltage (Vgs(th)): Must be compatible with 10V gate drive
• Operating Temperature Range: Must support -55°C to 175°C minimum

The three substitute parts listed below satisfy these mandatory criteria while maintaining electrical equivalence for direct replacement in applications designed for the IRLR3705Z.

Parameter Comparison

Engineering Selection Recommendations

BUK7212-55B,118 (Nexperia USA Inc.)

This substitute provides superior current handling (75A vs. 42A) and higher power dissipation capability (167W vs. 130W) while maintaining the 55V voltage rating. The device is AEC-Q101 qualified and ROHS3 compliant, offering improved compliance status over the obsolete IRLR3705Z. Gate charge is reduced (35nC vs. 66nC), resulting in faster switching characteristics. However, this part is also classified as obsolete, limiting long-term availability.

DMTH6010SK3Q-13 (Diodes Incorporated)

This substitute offers active product status, ensuring ongoing availability and manufacturing support. It is AEC-Q101 qualified and ROHS3 compliant. The device supports 60V Vdss (exceeding the 55V requirement) and delivers 70A continuous drain current. On-state resistance matches the main part specification (8mOhm). The primary consideration is the lower power dissipation rating (3.1W Ta vs. 130W Tc), which reflects a different thermal measurement methodology. This part is suitable for applications where thermal management is not the limiting factor.

STD60NF55LT4 (STMicroelectronics)

This substitute maintains active product status with ROHS3 compliance and extensive inventory availability (17,810 pcs). It matches the 55V voltage rating and provides 60A continuous drain current, exceeding the 42A requirement. The device features a lower gate threshold voltage (2V vs. 3V), enabling operation with lower gate drive voltages. On-state resistance is higher (15mOhm vs. 8mOhm), which may increase power dissipation in high-current applications. This part is recommended for applications prioritizing component availability and compliance over minimal on-state resistance.

Frequently Asked Questions (FAQ)

Q: Can I use BUK7212-55B,118 as a direct replacement for IRLR3705Z?

A: Yes, BUK7212-55B,118 is electrically compatible for direct replacement. Both devices share the same 55V Vdss rating, TO-252-3 (DPAK) package, and N-Channel MOSFET technology. The substitute provides higher current and power dissipation ratings, making it suitable for the same or more demanding applications. However, verify gate drive circuit compatibility, as Vgs(th) differs (4V vs. 3V).

Q: What is the difference between the power dissipation ratings for DMTH6010SK3Q-13?

A: DMTH6010SK3Q-13 specifies power dissipation as 3.1W (Ta), measured at ambient temperature, whereas IRLR3705Z specifies 130W (Tc), measured at case temperature. These represent different thermal measurement standards. The case temperature measurement (Tc) typically yields higher power dissipation values. For thermal design purposes, consult the device datasheet for thermal resistance (θJA and θJC) to calculate actual power dissipation under your operating conditions.

Q: Are all substitute parts RoHS compliant?

A: BUK7212-55B,118, DMTH6010SK3Q-13, and STD60NF55LT4 are all ROHS3 compliant. The original IRLR3705Z is RoHS non-compliant. If your application requires RoHS compliance, any of the three substitutes satisfy this requirement.

Q: Which substitute has the best long-term availability?

A: STD60NF55LT4 (STMicroelectronics) is classified as active product status with the highest inventory level (17,810 pcs). DMTH6010SK3Q-13 is also active status with 3,429 pcs available. BUK7212-55B,118 is obsolete, similar to the main part. For new designs requiring long-term component sourcing, STD60NF55LT4 or DMTH6010SK3Q-13 are preferred.

Q: Do all substitutes use the same gate drive voltage?

A: The main part and substitutes support 10V gate drive voltage. However, gate threshold voltages vary: IRLR3705Z (3V), BUK7212-55B,118 (4V), DMTH6010SK3Q-13 (4V), and STD60NF55LT4 (2V). Verify that your gate drive circuit can reliably turn on each device at its specified Vgs(th). Lower threshold voltages (STD60NF55LT4) enable operation with lower gate drive voltages.

Q: Can I use these substitutes in automotive applications?

A: BUK7212-55B,118 and DMTH6010SK3Q-13 are AEC-Q101 qualified, meeting automotive qualification standards. STD60NF55LT4 is not AEC-Q101 qualified. For automotive applications, BUK7212-55B,118 or DMTH6010SK3Q-13 are the appropriate choices.

Q: What is the impact of different on-state resistance values?

A: On-state resistance (Rds On) directly affects power dissipation and heat generation. IRLR3705Z and DMTH6010SK3Q-13 both specify 8mOhm, resulting in identical conduction losses at the same current. BUK7212-55B,118 (12mOhm) and STD60NF55LT4 (15mOhm) will generate more heat at high currents. For applications operating near maximum current ratings, lower Rds On values are preferred to minimize thermal stress.