40TPS12 Equivalent & Substitute Parts

Part Overview

The 40TPS12 is a 1.2 kV, 55 A standard recovery SCR manufactured by Vishay General Semiconductor - Diodes Division in TO-247AC package configuration. This component is classified as obsolete, making equivalent substitute parts necessary for ongoing system support and new design implementations. The part operates across a temperature range of -40°C to 125°C and is designed for through-hole mounting applications requiring thyristor switching functionality at 1.2 kV voltage levels.

Key Parameters

Parameter	Value	Unit
Voltage - Off State	1.2	kV
Current - On State (It (RMS))	55	A
Voltage - On State (Vtm) (Max)	1.85	V
Voltage - Gate Trigger (Vgt) (Max)	2.5	V
Current - Gate Trigger (Igt) (Max)	150	mA
Current - Hold (Ih) (Max)	150	mA
Operating Temperature Range	-40 to 125	°C
Package / Case	TO-247-3	-
SCR Type	Standard Recovery	-

Substitute Part Grouping Explanation

Substitution of the 40TPS12 is determined by strict equivalence across the following critical parameters:

Voltage rating: 1.2 kV off-state voltage
Current rating: Minimum 55 A RMS on-state current
Package type: TO-247-3 family (TO-247AC, TO-247J, TO-247-3 are mechanically and electrically compatible)
SCR classification: Standard recovery thyristor
Operating temperature range: Minimum -40°C to 125°C

Two active substitute parts meet these criteria: SCT1255SJ (SMC Diode Solutions) and TN5050H-12WY (STMicroelectronics). Both maintain the required voltage and current specifications while offering improved gate trigger characteristics and lower off-state leakage current compared to the obsolete 40TPS12.

Parameter Comparison

Parameter	40TPS12 (Vishay)	SCT1255SJ (SMC)	TN5050H-12WY (STMicroelectronics)	Unit
Voltage - Off State	1.2	1.2	1.2	kV
Current - On State (It (RMS))	55	55	80	A
Voltage - On State (Vtm) (Max)	1.85	1.6	1.55	V
Voltage - Gate Trigger (Vgt) (Max)	2.5	1.5	1.0	V
Current - Gate Trigger (Igt) (Max)	150	50	50	mA
Current - Hold (Ih) (Max)	150	120	100	mA
Current - Off State (Max)	500	10	5	µA
Operating Temperature Range	-40 to 125	-40 to 125	-40 to 150	°C
Package / Case	TO-247-3	TO-247-3	TO-247-3	-
Product Status	Obsolete	Active	Active	-
RoHS Status	Non-compliant	ROHS3 Compliant	ROHS3 Compliant	-

Engineering Selection Recommendations

Both substitute parts are active products with current manufacturing support, addressing the obsolescence of the 40TPS12.

SCT1255SJ provides direct current rating equivalence at 55 A RMS with improved electrical characteristics. The part demonstrates lower gate trigger voltage (1.5 V vs. 2.5 V) and significantly reduced off-state leakage current (10 µA vs. 500 µA). RoHS3 compliance and REACH affected status indicate current regulatory alignment. Packaging is specified as TO-247J, maintaining mechanical compatibility within the TO-247-3 family.

TN5050H-12WY offers enhanced current capability at 80 A RMS, exceeding the original 55 A specification. This part features the lowest gate trigger voltage (1.0 V) and minimal off-state leakage (5 µA). Extended operating temperature range to 150°C and AEC-Q101 automotive qualification provide additional design margin. RoHS3 compliance and REACH unaffected status confirm regulatory compliance. Standard TO-247-3 package designation ensures direct mechanical compatibility.

Selection between these substitutes depends on application requirements: SCT1255SJ for exact current rating matching, or TN5050H-12WY for applications benefiting from higher current capacity and extended temperature range.

Frequently Asked Questions (FAQ)

Q: Can SCT1255SJ and TN5050H-12WY be used interchangeably with 40TPS12?

A: Both parts meet the core electrical requirements of 1.2 kV voltage rating and minimum 55 A RMS current capacity. TO-247-3 family packages are mechanically compatible. However, improved gate trigger characteristics and lower leakage current in the substitutes may require circuit validation to confirm gate drive compatibility with existing designs.

Q: What is the difference between TO-247AC, TO-247J, and TO-247-3 packages?

A: All three designations refer to the same physical TO-247-3 package family with three leads. The suffix letters (AC, J, or -3) indicate manufacturer-specific package naming conventions but do not affect mechanical or electrical compatibility for through-hole mounting applications.

Q: Why does TN5050H-12WY have higher current rating (80 A) than the original 40TPS12 (55 A)?

A: The TN5050H-12WY is rated for 80 A RMS on-state current, which exceeds the original specification. This higher rating does not prevent substitution; it indicates improved thermal and electrical design. Applications requiring exactly 55 A operation will function correctly with this part.

Q: Are there compliance differences between the substitute parts?

A: SCT1255SJ carries REACH affected status, while TN5050H-12WY is REACH unaffected. Both are RoHS3 compliant. TN5050H-12WY includes AEC-Q101 automotive qualification. Selection should consider end-application regulatory requirements.

Q: What are the gate trigger improvements in the substitute parts?

A: The 40TPS12 requires maximum 2.5 V gate trigger voltage and 150 mA gate trigger current. SCT1255SJ reduces these to 1.5 V and 50 mA respectively. TN5050H-12WY further reduces gate trigger voltage to 1.0 V with 50 mA current. Lower gate trigger requirements reduce gate drive circuit complexity and power consumption.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message