2SA1859 Equivalent & Substitute Parts Reference Guide

Part Overview

The 2SA1859 is a PNP bipolar junction transistor (BJT) designed for high-voltage, medium-power amplification and switching applications. This device features a collector-emitter breakdown voltage of 150 V, a collector current rating of 2 A, a maximum power dissipation of 20 W, and is packaged in a TO-220-3 Full Pack (TO-220F) for through-hole mounting. The part has reached end-of-life as indicated by its “Obsolete” product status. Identifying and selecting alternative transistor models with matching or compatible key parameters is necessary to maintain design continuity and support the replacement of failed or depleted inventory.

Substiute Parts

2SA1859

Sanken Electric USA Inc.In Stock: 21392SA1859 Datasheet

Current PartRFQ

2SA1667

Sanken Electric USA Inc.In Stock: 77032SA1667 Datasheet

DirectRFQ

MJF15031G

onsemiIn Stock: 1626MJF15031G Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution is determined solely on compatibility of the transistor's critical electrical and mechanical parameters. The parameters reviewed include transistor type (PNP), maximum collector-emitter breakdown voltage (150 V), maximum collector current (2 A or greater where specified), power dissipation (equal or higher preferred), saturation voltage, DC current gain, cutoff current, transition frequency, operating temperature range, and package compatibility (TO-220 Full Pack). All listed alternatives have been selected solely based on alignment with these specified fields.

Parameter Comparison

Engineering Selection Recommendations

Product status and compliance are critical for engineering selection. The 2SA1859 is marked as "Obsolete" and "RoHS Compliant." Among substitute options, the 2SA1667 from Sanken Electric USA Inc. is an active part with ROHS3 compliance and MSL 1 rating. The MJF15031G from onsemi is also active, ROHS3 compliant, and not subject to moisture sensitivity limitations. All substitutes are classified as “Through Hole” devices and use the TO-220 full pack or equivalent package. Only parts with provided and matching RoHS environmental statuses are included.

Frequently Asked Questions (FAQ)

Q1: What are the primary parameters for determining functional equivalence in BJTs for replacement?
Key parameters include transistor type (PNP), collector-emitter breakdown voltage (maximum), collector current (maximum), power dissipation (maximum), gain (minimum hFE), transition frequency, saturation voltage, and mechanical compatibility (package type and mounting).

Q2: Why is package compatibility (TO-220-3 Full Pack / TO-220F) important in selecting substitutes?
Package compatibility ensures fit, thermal characteristics, and electrical connectivity, maintaining drop-in replacement ability without requiring PCB or heatsink modification.

Q3: How does RoHS status affect substitute part selection?
RoHS compliance is often a regulatory requirement. Only those replacements with explicit RoHS or ROHS3 compliant status and specified Moisture Sensitivity Level (MSL) are included as eligible substitutes.

Q4: What should be considered regarding the product status of the selected replacement transistor?
Replacement parts should be actively supported and available. Substitutes are only considered if their status is listed as "Active" and the compliance data is available. “Obsolete” entries are excluded as substitute options.

Q5: Can DC current gain (hFE) or frequency specifications affect substitution?
Yes. Substitute selection is based on provided hFE minimum and frequency transition values, ensuring functionally equivalent performance in amplification or switching roles. Only those matching or exceeding the critical parameter thresholds are considered.