Diodes Incorporated ZTX415STOB

Overview

ZTX415STOB from Diodes Incorporated is an NPN silicon planar medium-power transistor engineered for controlled avalanche-mode operation, featuring BVCES > 260 V, BVCEO > 100 V, and 60 A peak avalanche current (20 ns pulse), used in high-voltage pulse generators and snubber circuits for flyback converters.

For engineers reviewing the ZTX415STOB datasheet, ZTX415STOB pinout, ZTX415STOB application, or ZTX415STOB equivalent, key selection criteria include avalanche energy handling, VCEO derating at elevated temperature, E-Line package thermal resistance (RθJL = 197 °C/W), and JEDEC Class 3A HBM ESD rating (4,000 V).

Technical Context

This transistor uses a planar epitaxial structure optimized for second-breakdown robustness and repeatable avalanche triggering. Its BVCES rating exceeds 260 V with IC = 1 mA across –55°C to +150°C, and it sustains pulsed IUSB up to 35 A under VC = 250 V with 620 pF load capacitance.

The E-Line package enables direct lead soldering to 15 mm × 15 mm 1 oz copper pads, delivering RθJA = 250 °C/W under still-air conditions. Transition frequency fT = 40 MHz at VCE = 20 V, IC = 10 mA confirms suitability for medium-speed switching above audio frequencies.

Key Specifications

Pinout & Package

E-Line package: molded plastic case (UL 94V-0), matte tin-plated leads, 159 mg mass, moisture sensitivity level 1. Dimensions: D = 4.57 mm, E = 3.90 mm, L = 13.50 mm, e = 1.27 mm (REF), e2 = 2.54 mm (REF).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar avalanche-mode switching applications.

Compared with ZTX453 and MPSA42, ZTX415STOB uniquely combines 100 V VCEO, 260 V BVCES, and validated 60 A/20 ns avalanche performance in the thermally efficient E-Line package-making it the only choice for reliable, repeatable high-energy pulse clamping.

Availability

ZTX415STOB is available at Aetrix Electronics and suitable for high-voltage pulse generation, flyback snubbing, and inductive load switching requiring stable component supply and long-term industrial lifecycle support.

Supply support for ZTX415STOB includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the Americas.

The ZTX series targets medium-power bipolar switching applications demanding ruggedness, high-voltage capability, and repeatable avalanche behavior-especially in industrial power conversion and pulse circuitry.

FAQ

What is the maximum allowable continuous power dissipation for ZTX415STOB?

The absolute maximum continuous power dissipation is 680 mW at TA = +25°C with the collector lead mounted on a 15 mm × 15 mm 1 oz copper pad on FR-4. Derating is required above +25°C at 2.72 mW/°C based on RθJA = 250 °C/W. Exceeding this limit risks thermal runaway due to positive temperature coefficient of hFE.

Can ZTX415STOB be used as a linear amplifier?

Yes, but only in narrow applications: its hFE ≥ 25 at IC = 10 mA, VCE = 10 V supports small-signal amplification, yet its 680 mW power limit and lack of guaranteed linearity specs (e.g., distortion, fT flatness) make it inferior to purpose-built RF or audio transistors. It is optimized for switching and avalanche, not analog fidelity.

Is ZTX415STOB pin-compatible with ZTX453?

Yes-both use identical E-Line packaging and share the same C-B-E pinout (top view: Collector left, Base center, Emitter right). Markings differ (ZTX415 vs. ZTX453), but PCB footprints, solder pads, and wiring are fully interchangeable. Electrical differences require circuit revalidation, especially for VCEO and avalanche margin.

Does ZTX415STOB require a heatsink in pulsed operation?

No heatsink is needed for pulsed avalanche operation (e.g., 20 ns, 60 A) because energy per pulse is low (~12 mJ) and duty cycle is typically <0.1%. The E-Line package's RθJL = 197 °C/W provides sufficient transient thermal conduction through the collector lead to copper, provided the PCB layout maintains ≥15 mm² of 1 oz copper connected to that lead.