F1857HD1200 Equivalent & Substitute Parts

Part Overview

The F1857HD1200 is an SCR/Diode thyristor module manufactured by Sensata-Crydom, designed for 1.2 kV series connection applications with chassis mount configuration. This component is classified as obsolete, necessitating identification of functionally equivalent alternatives for ongoing system maintenance and new designs. The module integrates one SCR and one diode in a single package, suitable for high-voltage switching applications up to 480 VAC.

Substiute Parts

F1857HD1200

Sensata-CrydomIn Stock: 913F1857HD1200 Datasheet

Current PartRFQ

VS-VSKH56/12

Vishay General Semiconductor - Diodes DivisionIn Stock: 1086VS-VSKH56/12 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

The VS-VSKH56/12 qualifies as a direct substitute for the F1857HD1200 based on the following critical parameters:

• Voltage - Off State: Both components operate at 1.2 kV, ensuring compatibility in high-voltage switching circuits
• Structure: Both employ series connection SCR/Diode architecture with identical component count (1 SCR, 1 Diode)
• Gate Trigger Parameters: Both maintain maximum gate trigger voltage (Vgt) within acceptable range and identical maximum gate trigger current (Igt) of 150 mA
• Operating Temperature Range: Both support -40°C ~ 125°C (TJ), ensuring thermal compatibility
• Mounting Type: Both are chassis mount modules, maintaining mechanical compatibility
• RoHS Compliance: The substitute part meets ROHS3 compliance, exceeding the RoHS compliance of the original part

The VS-VSKH56/12 is manufactured by Vishay General Semiconductor - Diodes Division and carries active product status, making it suitable for applications requiring the F1857HD1200.

Parameter Comparison

Engineering Selection Recommendations

The VS-VSKH56/12 is the recommended substitute for the obsolete F1857HD1200. Selection is based on the following engineering criteria:

• Product Status Alignment: The substitute part carries active product status, ensuring long-term availability and supply chain continuity
• Compliance Enhancement: The VS-VSKH56/12 meets ROHS3 compliance, providing improved environmental and regulatory alignment compared to the original RoHS Compliant designation
• Electrical Equivalence: Both components share identical off-state voltage (1.2 kV), gate trigger current (150 mA), and operating temperature range, confirming functional compatibility
• Structural Compatibility: Identical SCR/Diode series connection architecture and chassis mount configuration ensure mechanical and electrical integration without circuit redesign
• Regulatory Alignment: Both components carry EAR99 ECCN classification and identical HTSUS codes (8541.30.0080), maintaining export and import compliance

Frequently Asked Questions (FAQ)

Q: Can the VS-VSKH56/12 directly replace the F1857HD1200 in existing circuits?

A: Yes. Both components share identical off-state voltage (1.2 kV), gate trigger current (150 mA), operating temperature range (-40°C ~ 125°C), and series connection SCR/Diode structure. The substitute part is mechanically and electrically compatible for direct substitution.

Q: What is the difference in package configuration between these parts?

A: The F1857HD1200 uses a standard Module package, while the VS-VSKH56/12 uses ADD-A-PAK (3 + 4) configuration. Both are chassis mount modules; however, physical dimensions and mounting hole patterns may differ. Mechanical verification is required for board-level integration.

Q: Why is the gate trigger voltage (Vgt) lower on the VS-VSKH56/12?

A: The VS-VSKH56/12 specifies a maximum Vgt of 2.5 V compared to 3 V for the F1857HD1200. This represents improved gate sensitivity and does not affect substitution compatibility, as the lower value remains within acceptable triggering parameters for standard gate drive circuits.

Q: Are there any current rating differences to consider?

A: The F1857HD1200 specifies non-repetitive surge current (Itsm) of 1500 A @ 60Hz, while the VS-VSKH56/12 specifies 1200 A and 1256 A. For applications requiring surge current handling above 1256 A, the original part specifications should be retained. For standard operating conditions, the substitute part is suitable.

Q: What compliance certifications apply to both parts?

A: Both components are RoHS compliant (the substitute meets the enhanced ROHS3 standard), carry EAR99 ECCN classification, and share identical HTSUS code 8541.30.0080. The substitute part is REACH Unaffected, providing additional regulatory assurance.