SA170A Transient Voltage Suppressor (TVS) Diode - Equivalent & Substitute Parts

Part Overview

The SA170A is a unidirectional Zener-type transient voltage suppressor diode manufactured by onsemi, designed for general-purpose overvoltage protection applications. Packaged in DO-15 (DO-204AC) through-hole configuration, this component provides 275V clamping voltage with 1.8A peak pulse current capability. The SA170A is classified as obsolete, necessitating identification of active equivalent and substitute parts to maintain design continuity and ensure supply chain availability for new production and field replacements.

Key Parameters

Parameter	Value
Voltage - Reverse Standoff (Typ)	170V
Voltage - Breakdown (Min)	189V
Voltage - Clamping (Max) @ Ipp	275V
Current - Peak Pulse (10/1000µs)	1.8A
Power - Peak Pulse	500W
Type	Zener
Unidirectional Channels	1
Mounting Type	Through Hole
Package / Case	DO-204AC, DO-15, Axial
Applications	General Purpose

Substitute Part Grouping Explanation

Substitution of the SA170A is determined by strict equivalence across the following electrical and mechanical parameters:

Voltage - Reverse Standoff (Typ): 170V
Voltage - Breakdown (Min): 189V
Voltage - Clamping (Max) @ Ipp: 275V
Current - Peak Pulse (10/1000µs): 1.8A to 1.9A (within tolerance)
Power - Peak Pulse: 500W
Type: Zener, Unidirectional
Mounting Type: Through Hole
Package / Case: DO-204AC or DO-15

Parts are categorized as follows:

Direct Equivalents: Parts with identical electrical specifications and active product status, differing only in manufacturer or packaging format (bulk vs. tape & reel).

Similar Alternatives: Parts meeting core voltage and clamping specifications with minor variations in peak pulse current or operating temperature range, suitable for general-purpose applications where these variations do not impact circuit performance.

Parameter Comparison

Part Number	Manufacturer	Product Status	Vwm (Typ) [V]	Vbr (Min) [V]	Vc (Max) @ Ipp [V]	Ipp [A]	Ppk [W]	Package	Packaging
SA170A	onsemi	Obsolete	170	189	275	1.8	500	DO-15	-
SA170A-AP	Micro Commercial Co	Active	170	189	275	1.9	500	DO-15	Bulk
SA170A-BP	Micro Commercial Co	Active	170	189	275	1.9	500	DO-15	Bulk
SA170A-E3/54	Vishay General Semiconductor - Diodes Division	Active	170	189	275	1.8	500	DO-204AC (DO-15)	Tape & Reel (TR)
SA170AHE3/54	Vishay General Semiconductor - Diodes Division	Active	170	189	275	1.8	500	DO-204AC (DO-15)	Tape & Reel (TR)
P5KE170A-AP	Micro Commercial Co	Active	170	189	275	1.8	500	DO-15	Bulk
P5KE170A-BP	Micro Commercial Co	Active	170	189	275	1.8	500	DO-15	Bulk
P5KE170A-TP	Micro Commercial Co	Active	170	189	275	1.8	500	DO-15	Bulk
SA170A	Taiwan Semiconductor Corporation	Active	170	189	275	0.1	500	DO-204AC (DO-15)	Tape & Reel (TR)
SA170A-TP	Micro Commercial Co	Active	170	189	275	1.9	500	DO-15	Bulk

Engineering Selection Recommendations

Primary Substitutes (Direct Equivalents):

SA170A-E3/54 and SA170AHE3/54 from Vishay General Semiconductor - Diodes Division are the preferred direct substitutes. Both maintain identical electrical specifications (170V standoff, 189V breakdown, 275V clamping, 1.8A peak pulse) and are available in active product status. SA170A-E3/54 is RoHS3 compliant and suitable for general-purpose applications. SA170AHE3/54 carries AEC-Q101 automotive qualification and is designated for automotive-grade applications requiring enhanced reliability standards.

SA170A-AP, SA170A-BP, and SA170A-TP from Micro Commercial Co are active equivalents with marginally higher peak pulse current (1.9A vs. 1.8A), providing additional current margin. All three maintain identical voltage specifications and 500W peak power rating. These parts are available in bulk packaging.

Secondary Alternatives (Similar Specifications):

P5KE170A-AP, P5KE170A-BP, and P5KE170A-TP from Micro Commercial Co meet core voltage and clamping requirements with identical 1.8A peak pulse current and 500W peak power. Operating temperature range extends to -65°C (vs. -55°C for SA170A variants), providing enhanced low-temperature performance. These parts are suitable for general-purpose applications where the extended temperature range provides design margin.

SA170A from Taiwan Semiconductor Corporation maintains voltage specifications but features significantly reduced peak pulse current (100mA vs. 1.8A). This part is suitable only for low-current transient suppression applications and is not recommended as a general substitute for the original SA170A.

Frequently Asked Questions (FAQ)

Q: Can SA170A-AP or SA170A-BP be used as direct replacements for the obsolete SA170A?

A: Yes. Both parts maintain identical voltage specifications (170V standoff, 189V breakdown, 275V clamping) and 500W peak power rating. The 1.9A peak pulse current (vs. 1.8A) provides additional current margin and does not compromise circuit compatibility. Both are active products available in bulk packaging.

Q: What is the difference between SA170A-E3/54 and SA170AHE3/54?

A: Both parts are electrically identical with 170V standoff, 189V breakdown, 275V clamping, and 1.8A peak pulse current. SA170AHE3/54 carries AEC-Q101 automotive qualification and is designated for automotive applications. SA170A-E3/54 is suitable for general-purpose applications. Both are available in tape & reel packaging and RoHS3 compliant.

Q: Are P5KE170A variants suitable substitutes?

A: P5KE170A-AP, P5KE170A-BP, and P5KE170A-TP meet core electrical specifications with identical 1.8A peak pulse current and 275V clamping voltage. Operating temperature range extends to -65°C, providing enhanced low-temperature performance. These parts are suitable for general-purpose applications where extended temperature range is beneficial.

Q: What packaging options are available?

A: Substitute parts are available in two packaging formats: bulk (SA170A-AP, SA170A-BP, SA170A-TP, P5KE170A variants) and tape & reel (SA170A-E3/54, SA170AHE3/54). All parts use DO-15 or DO-204AC (equivalent) through-hole packages. Selection depends on production volume and assembly requirements.

Q: Can the Taiwan Semiconductor Corporation SA170A be used as a substitute?

A: This part is not recommended as a general substitute. While voltage specifications are identical, peak pulse current is limited to 100mA (vs. 1.8A for the original SA170A). Use is restricted to low-current transient suppression applications only.

Q: Are there compliance or certification differences among substitutes?

A: SA170A-E3/54 and SA170AHE3/54 are RoHS3 compliant. SA170AHE3/54 carries AEC-Q101 automotive qualification for automotive-grade applications. All parts are REACH unaffected and classified under ECCN EAR99. Compliance requirements should be verified against specific application standards.

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