MBR4045PT Equivalent & Substitute Parts

Part Overview

The MBR4045PT is a Schottky diode array manufactured by Taiwan Semiconductor Corporation, configured as a 1 Pair Common Cathode rectifier with a maximum reverse voltage of 45 V and average rectified current of 40 A per diode. The device is packaged in TO-247-3 through-hole configuration and is classified as Active product status with RoHS3 compliance.

Substitute parts are necessary when the MBR4045PT becomes unavailable from inventory, when alternative manufacturers are required for supply chain diversification, or when design specifications permit operation at reduced current ratings or with different forward voltage characteristics within the same voltage class and package family.

Key Parameters

Parameter	Value	Unit
Diode Configuration	1 Pair Common Cathode	—
Technology	Schottky	—
Voltage - DC Reverse (Vr) (Max)	45	V
Current - Average Rectified (Io) (per Diode)	40	A
Voltage - Forward (Vf) (Max) @ If	800 mV @ 40 A	—
Speed	Fast Recovery ≤ 500ns, > 200mA (Io)	—
Current - Reverse Leakage @ Vr	1	mA @ 45 V
Operating Temperature - Junction	-55 to 150	°C
Mounting Type	Through Hole	—
Package / Case	TO-247-3	—
RoHS Status	RoHS3 Compliant	—

Substitute Part Grouping Explanation

Substitution of the MBR4045PT is determined by strict adherence to the following electrical and mechanical parameters:

Mandatory Matching Parameters:

Diode Configuration: 1 Pair Common Cathode
Technology: Schottky
Voltage - DC Reverse (Vr) (Max): 45 V
Mounting Type: Through Hole
Package / Case: TO-247-3

Allowable Variation Parameters:

Current - Average Rectified (Io) (per Diode): Equal to or greater than required circuit current
Voltage - Forward (Vf) (Max) @ If: Lower values indicate improved efficiency; higher values remain acceptable within thermal design limits
Current - Reverse Leakage @ Vr: Variation acceptable within circuit leakage budget
Operating Temperature - Junction: Maximum rating must meet or exceed circuit operating requirements

Substitute parts are grouped into three categories based on current rating:

Category A (20 A Rating): MBR4045WT, 40CPQ045, STPS4045CW, STPS40L45CW Category B (15 A Rating): STPS3045CW, STPS30L45CW Category C (30 A Rating): STPS6045CW, STPS60L45CW, STPS61L45CW

Parameter Comparison

Part Number	Manufacturer	Io (A)	Vf (Max) @ If	Vr (Max) (V)	Tj (Max) (°C)	Product Status	RoHS Status
MBR4045PT	Taiwan Semiconductor Corporation	40	800 mV @ 40 A	45	150	Active	RoHS3 Compliant
MBR4045WT	Vishay General Semiconductor - Diodes Division	20	590 mV @ 20 A	45	150	Obsolete	RoHS Non-compliant
40CPQ045	SMC Diode Solutions	20	490 mV @ 20 A	45	150	Active	RoHS3 Compliant
STPS3045CW	STMicroelectronics	15	570 mV @ 15 A	45	200	Active	RoHS3 Compliant
STPS30L45CW	STMicroelectronics	15	550 mV @ 15 A	45	150	Active	RoHS3 Compliant
STPS4045CW	STMicroelectronics	20	760 mV @ 20 A	45	175	Active	RoHS3 Compliant
STPS40L45CW	STMicroelectronics	20	530 mV @ 20 A	45	150	Active	RoHS3 Compliant
STPS6045CW	STMicroelectronics	30	630 mV @ 30 A	45	175	Active	RoHS3 Compliant
STPS60L45CW	STMicroelectronics	30	550 mV @ 30 A	45	150	Active	RoHS3 Compliant
STPS61L45CW	STMicroelectronics	30	560 mV @ 30 A	45	150	Active	RoHS3 Compliant

Engineering Selection Recommendations

Primary Substitutes (Preferred Selection):

STPS40L45CW and STPS4045CW are the preferred substitutes for the MBR4045PT when 20 A operation is acceptable. Both parts are manufactured by STMicroelectronics, carry Active product status, and maintain RoHS3 compliance. STPS40L45CW offers superior forward voltage characteristics (530 mV @ 20 A) compared to the original part (800 mV @ 40 A), resulting in reduced power dissipation. STPS4045CW provides equivalent forward voltage performance at 760 mV @ 20 A with extended junction temperature rating to 175°C.

40CPQ045 from SMC Diode Solutions is an alternative 20 A substitute with Active status and RoHS3 compliance. This part exhibits the lowest forward voltage (490 mV @ 20 A) among 20 A options, providing optimal thermal performance.

Secondary Substitutes (Current-Reduced Applications):

STPS3045CW and STPS30L45CW are suitable for applications where circuit current does not exceed 15 A. Both maintain 45 V reverse voltage rating and TO-247-3 packaging. STPS3045CW extends maximum junction temperature to 200°C, while STPS30L45CW maintains 150°C with lower forward voltage (550 mV @ 15 A).

Higher Current Alternatives (Derating Applications):

STPS6045CW, STPS60L45CW, and STPS61L45CW provide 30 A current ratings and are suitable for applications requiring thermal margin or future current expansion within the 45 V class. All three maintain Active status and RoHS3 compliance with TO-247-3 packaging.

Obsolete Part Consideration:

MBR4045WT from Vishay carries Obsolete product status and RoHS non-compliance. This part is not recommended for new designs despite electrical compatibility.

Frequently Asked Questions (FAQ)

Q: Can STPS40L45CW directly replace MBR4045PT in all applications?

A: STPS40L45CW is electrically compatible for applications where circuit current does not exceed 20 A. The part maintains identical 45 V reverse voltage rating, TO-247-3 package, and fast recovery Schottky technology. Forward voltage is lower (530 mV @ 20 A versus 800 mV @ 40 A), resulting in reduced power dissipation. Applications requiring the full 40 A rating of the MBR4045PT cannot use this substitute.

Q: What is the difference between STPS40L45CW and STPS4045CW?

A: Both parts are 20 A rated Schottky diodes in TO-247-3 packaging with 45 V reverse voltage. STPS40L45CW exhibits lower forward voltage (530 mV @ 20 A) and maximum junction temperature of 150°C. STPS4045CW has forward voltage of 760 mV @ 20 A with extended maximum junction temperature of 175°C. Selection depends on thermal design requirements and power dissipation budget.

Q: Are all substitute parts RoHS3 compliant?

A: All substitute parts listed are RoHS3 compliant except MBR4045WT, which carries RoHS non-compliance status. MBR4045WT is also classified as Obsolete and is not recommended for new designs.

Q: Can I use a 15 A rated part (STPS3045CW or STPS30L45CW) in place of the 40 A MBR4045PT?

A: 15 A rated parts are suitable only for applications where circuit current does not exceed 15 A. These parts maintain the same 45 V reverse voltage rating and TO-247-3 package. Use of 15 A parts in circuits requiring higher current will result in device thermal stress and potential failure.

Q: What is the advantage of 30 A rated substitutes (STPS6045CW, STPS60L45CW, STPS61L45CW)?

A: 30 A rated parts provide thermal margin and current derating capability for applications operating below their maximum rating. These parts are suitable for circuits requiring 20 A to 30 A operation and offer improved reliability through reduced thermal stress compared to parts operating at their maximum current rating.

Q: Are there package differences between substitute parts?

A: All substitute parts and the MBR4045PT use TO-247-3 through-hole packaging. Mechanical compatibility is maintained across all listed parts. Mounting and PCB layout remain identical.

Q: How do forward voltage differences affect circuit performance?

A: Forward voltage variation directly impacts power dissipation and thermal performance. Lower forward voltage (STPS40L45CW at 530 mV @ 20 A) reduces heat generation compared to higher forward voltage (STPS4045CW at 760 mV @ 20 A). Circuit thermal design must account for these differences when selecting substitutes.

Q: Can MBR4045WT be used despite its Obsolete status?

A: MBR4045WT is not recommended for new designs due to Obsolete product status and RoHS non-compliance. Existing inventory may be available, but long-term supply cannot be assured. Active alternatives such as STPS40L45CW or 40CPQ045 are preferred for design continuity.

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