Diodes Incorporated FZT851QTA

Overview

FZT851QTA from Diodes Incorporated is an AEC-Q101-qualified 60V NPN medium-power transistor in SOT223 package, delivering 6A continuous collector current, <100mV V_CE(sat) at 1A, and 44mΩ equivalent on-resistance. It serves as a high-current switching element in automotive power management, DC-DC converters, and motor drive stages where low conduction loss and thermal robustness are critical.

For engineers reviewing the FZT851QTA datasheet, FZT851QTA pinout, FZT851QTA application, or FZT851QTA equivalent, key selection criteria include its 60V V_CEO, 6A I_C, AEC-Q101 qualification, SOT223 thermal performance (R_θJA = 42°C/W on 52mm×52mm 2oz Cu), and complementary pairing with FZT951.

Technical Context

The FZT851QTA is a silicon NPN bipolar junction transistor optimized for medium-power linear and switching applications. Its design emphasizes high current handling (6A continuous, 20A pulse), low saturation voltage (≤100mV @ 1A), and stable gain up to 10A (h_FE ≥75), enabling efficient operation in automotive load switches and power supply control circuits.

It features a rugged SOT223 (Type DN) package with exposed collector tab for enhanced thermal dissipation, RoHS-compliant matte tin plating, and moisture sensitivity level 1. The device operates across −55°C to +150°C and meets JEDEC JESD22-A114 HBM ESD rating of 8kV.

Key Specifications

Pinout & Package

SOT223 (Type DN) package with molded green plastic case (UL 94V-0), exposed collector tab for thermal conduction, and matte tin-plated leads solderable per MIL-STD-202 Method 208. Weight: 0.112g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZXTN25050DFHTA and MJD127G, the FZT851QTA uniquely balances AEC-Q101 compliance, SOT223 mountability, 60V robustness, and 6A capability-making it the optimal choice for space-constrained, thermally demanding automotive power stages.

Availability

FZT851QTA is available at Aetrix Electronics and suitable for automotive body control modules, 12V DC-DC converters, and industrial motor starter circuits requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for FZT851QTA 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 the Americas.

The FZT851QTA belongs to Diodes' automotive-qualified power transistor product line, engineered specifically for high-reliability, thermally efficient switching in 12V/24V vehicle electrical systems.

FAQ

What is the maximum allowable junction temperature for FZT851QTA?

The FZT851QTA has an operating junction temperature range of −55°C to +150°C. Its absolute maximum T_J is 150°C; sustained operation above this limit risks permanent degradation. Thermal design must ensure T_J remains within spec using R_θJA = 42°C/W (52mm×52mm 2oz Cu) or R_θJL = 8.8°C/W with proper collector-tab mounting.

Is FZT851QTA pin-compatible with FZT851TA?

Yes-FZT851QTA and FZT851TA share identical SOT223 pinout, electrical specifications, and mechanical dimensions. The "Q" suffix denotes AEC-Q101 qualification, PPAP capability, and IATF16949 manufacturing, while "TA" is the commercial-grade version. Both use the same marking layout and tape-and-reel packaging (1000 pcs/reel).

Can FZT851QTA replace a MOSFET in a 12V switching application?

FZT851QTA can replace low-voltage N-channel MOSFETs in applications where gate drive simplicity and cost matter more than ultra-low R_DS(on). Unlike MOSFETs, it requires base current (e.g., 50mA for 1A I_C) and exhibits higher conduction loss than modern 12V MOSFETs-but offers superior surge tolerance (20A I_CM) and inherent ruggedness against avalanche and dv/dt-induced turn-on.

What is the recommended PCB layout for thermal performance?

For optimal thermal performance, connect the exposed collector tab to a minimum 52mm×52mm copper area (2oz) on the top layer, with ≥6 thermal vias (0.3mm diameter) to inner ground/power planes. Follow Diodes' suggested SOT223 pad layout (C1 = 6.40mm, Y2 = 8.00mm) and maintain ≥0.25mm clearance from adjacent traces to avoid solder wicking.