Diodes Incorporated FZT851TC

Overview

FZT851TC from Diodes Incorporated is a 60V NPN medium-power transistor in SOT223 package, rated for 6A continuous collector current and 20A peak pulse current, with V_CE(sat) < 100 mV at 1 A and R_CE(sat) = 44 mΩ; used in high-current switching circuits such as DC-DC converter output stages and motor driver half-bridges.

For engineers reviewing the FZT851TC datasheet, FZT851TC pinout, FZT851TC application, or FZT851TC equivalent, key selection criteria include verified V_CEO = 60 V, h_FE ≥ 75 at 5 A, thermal resistance R_θJA = 42 °C/W (52 mm × 52 mm 2 oz Cu), ESD HBM = 8 kV, and AEC-Q101 qualification status for automotive-grade reliability.

Technical Context

This NPN bipolar junction transistor operates in linear or saturated switching mode with guaranteed BV_CEO ≥ 60 V and BVCBO ≥ 150 V, supporting robust voltage margin in 48 V industrial and automotive power rails. Its h_FE is specified up to 10 A, enabling stable current amplification under high-load conditions without gain collapse.

The device features low V_CE(sat) (≤100 mV @ 1 A) and ultra-low R_CE(sat) (44 mΩ), minimizing conduction loss in high-duty-cycle applications. Thermal performance is validated per JESD51-2 with R_θJL = 8.8 °C/W, confirming efficient heat transfer through the collector lead to PCB copper.

Key Specifications

Pinout & Package

Package: SOT223 (Type DN), surface-mount, molded plastic case with matte tin-plated leads; UL 94V-0 rated, moisture sensitivity level 1, weight ≈ 0.112 g.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN medium-power transistor applications.

Compared with ZXTN2012E6TA and MJD122T4G, FZT851TC delivers optimal balance of 6 A current, 44 mΩ on-resistance, and SOT223 thermal performance-making it superior for 48 V industrial switching where both efficiency and manufacturability matter.

Availability

FZT851TC is available at Aetrix Electronics and suitable for automotive body control modules, industrial 48 V DC-DC converters, and brushed DC motor drivers requiring stable component supply across multi-year production cycles.

Supply support for FZT851TC 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, manufacturing, and sales operations across Asia, Europe, and North America.

The FZT851TC belongs to Diodes' high-reliability power transistor product line, engineered specifically for automotive and industrial switching applications demanding AEC-Q101 compliance, low R_CE(sat), and robust thermal performance in compact packages.

FAQ

Is FZT851TC pin-compatible with FZT951?

No, FZT851TC (NPN) and FZT951 (PNP) are complementary devices with identical SOT223 pinout but opposite polarity. Their pin assignments match (C-E-B), but they cannot substitute for each other electrically. Both share identical mechanical dimensions and thermal characteristics, enabling symmetrical layout in push-pull or H-bridge designs.

What is the maximum allowable PCB copper area for thermal derating?

The 42 °C/W R_θJA rating assumes a 52 mm × 52 mm 2 oz copper pad connected to the collector tab. Reducing copper area to 25 mm × 25 mm 1 oz raises R_θJA to 78 °C/W. For continuous 3 W operation, minimum recommended copper is 35 mm × 35 mm 2 oz to maintain junction temperature below 125 °C at 70 °C ambient.

Does FZT851TC support linear-mode operation?

Yes-its SOA curve is explicitly characterized for linear operation up to 100 µs pulses and DC conditions with proper heatsinking. At V_CE = 20 V and I_C = 1.5 A, it dissipates 30 W transiently; continuous linear use requires active cooling or strict duty-cycle limiting to stay within the 3 W PD rating at ambient.

How does the "Q" suffix differ from standard FZT851TC?

The "Q" suffix (e.g., FZT851Q) denotes full AEC-Q101 qualification with PPAP documentation, IATF 16949 manufacturing, and controlled change management-required for automotive safety-critical systems. Standard FZT851TC meets all electrical specs but lacks formal automotive certification documentation and may have broader process tolerances.