SA170 Transient Voltage Suppressor (TVS) Diode - Equivalent & Substitute Parts

Part Overview

The SA170 is a unidirectional Zener-type transient voltage suppressor diode manufactured by Littelfuse, designed for general-purpose overvoltage protection applications. The device features a 170V reverse standoff voltage rating with a 288.75V maximum clamping voltage and 1.9A peak pulse current capability in a through-hole DO-204AC (DO-15) axial package. The SA170 is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements. Active alternatives with comparable electrical characteristics and identical package configurations are available from multiple manufacturers.

Substiute Parts

SA170

LittelfuseIn Stock: 953SA170 Datasheet

Current PartRFQ

SA170A

Taiwan Semiconductor CorporationIn Stock: 1033SA170A Datasheet

DirectRFQ

P5KE170A-TP

Micro Commercial CoIn Stock: 984P5KE170A-TP Datasheet

MFR RecommendedRFQ

SA170A-AP

Micro Commercial CoIn Stock: 1216SA170A-AP Datasheet

MFR RecommendedRFQ

SA170A-BP

Micro Commercial CoIn Stock: 1026SA170A-BP Datasheet

MFR RecommendedRFQ

SA170A-TP

Micro Commercial CoIn Stock: 984SA170A-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SA170 is determined by strict alignment of the following electrical and mechanical parameters:

Critical Substitution Parameters:

• Voltage - Reverse Standoff (Typ): 170V
• Package / Case: DO-204AC (DO-15) axial through-hole
• Mounting Type: Through Hole
• Unidirectional Channels: 1
• Type: Zener
• Power - Peak Pulse: 500W
• Operating Temperature Range: -55°C to 175°C minimum

Acceptable Variation Range:

• Voltage - Breakdown (Min): 179.1V to 189V
• Voltage - Clamping (Max) @ Ipp: 275V to 288.75V
• Current - Peak Pulse (10/1000µs): 100mA to 1.9A

All substitute parts listed maintain identical reverse standoff voltage, package configuration, and mounting type. Variations in clamping voltage and peak pulse current remain within the functional tolerance band for general-purpose transient suppression applications.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Highest Compatibility):

SA170A-AP, SA170A-BP, and SA170A-TP from Micro Commercial Co are direct functional equivalents with active product status. These parts maintain the original 1.9A peak pulse current specification, identical operating temperature range (-55°C to 175°C), and full ROHS3 compliance with REACH unaffected status. All three variants are available in bulk packaging with inventory levels exceeding 950 units.

Secondary Substitute (Extended Temperature Range):

P5KE170A-TP from Micro Commercial Co provides an extended operating temperature range (-65°C to 175°C) with 1.8A peak pulse current, meeting the original 500W power dissipation requirement. This option is suitable for applications requiring enhanced low-temperature performance.

Alternative Substitute (Lower Current Rating):

SA170A from Taiwan Semiconductor Corporation is an active product with ROHS3 compliance and REACH unaffected status. The 100mA peak pulse current rating represents a significant reduction from the original 1.9A specification and is suitable only for applications with reduced transient energy requirements.

All substitute parts maintain ROHS3 compliance and are classified as REACH unaffected, ensuring regulatory alignment with the original SA170 specification.

Frequently Asked Questions (FAQ)

Q: Can SA170A from Taiwan Semiconductor Corporation directly replace the SA170 in all applications?

A: SA170A maintains the critical parameters of 170V reverse standoff voltage, DO-204AC (DO-15) package, and 500W peak pulse power rating. However, the 100mA peak pulse current is substantially lower than the original 1.9A specification. Substitution is valid only for applications where transient energy levels do not exceed the reduced current capability.

Q: What is the difference between SA170A-AP, SA170A-BP, and SA170A-TP?

A: All three variants from Micro Commercial Co are electrically identical with 1.9A peak pulse current, 275V clamping voltage, and -55°C to 175°C operating temperature range. The designations (AP, BP, TP) indicate different packaging or supplier configurations. Selection among these three is based on procurement and inventory availability rather than electrical performance.

Q: Is P5KE170A-TP suitable for applications requiring the original -55°C minimum operating temperature?

A: Yes. P5KE170A-TP extends the minimum operating temperature to -65°C, which exceeds the original -55°C requirement. This part is fully compatible with applications designed for the SA170's temperature range and provides additional margin for cold-environment operation.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All listed substitute parts—SA170A, P5KE170A-TP, SA170A-AP, SA170A-BP, and SA170A-TP—are ROHS3 compliant and REACH unaffected, maintaining full regulatory alignment with the original SA170 specification.

Q: Can substitute parts be used interchangeably in existing PCB designs?

A: Yes. All substitute parts use the DO-204AC (DO-15) axial through-hole package with identical pin configuration and mechanical dimensions. Direct PCB substitution is possible without layout modifications.

Q: What inventory levels are available for each substitute part?

A: SA170A (Taiwan Semiconductor): 1,019 units; P5KE170A-TP (Micro Commercial): 917 units; SA170A-AP (Micro Commercial): 1,183 units; SA170A-BP (Micro Commercial): 961 units; SA170A-TP (Micro Commercial): 950 units.