Diodes Incorporated FCX790ATA

Overview

FCX790ATA from Diodes Incorporated is a PNP silicon power switching transistor in SOT89 package, rated for -40V V_CEO, -2A continuous collector current, and 2W power dissipation at optimized PCB layout. It delivers low saturation voltage (≤ -250mV @ -500mA), high DC current gain (h_FE = 300–800), and 100MHz f_T, enabling efficient on/off control in automotive load switching and industrial DC-DC converter bias circuits.

For engineers reviewing the FCX790ATA datasheet, FCX790ATA pinout, FCX790ATA application, or FCX790ATA equivalent, key selection criteria include verified PNP switching capability under -2A steady-state loads, thermal performance on 40mm×40mm copper, V_CE(sat) stability across -0.5A to -2A, and AEC-Q101 qualification readiness for automotive-grade designs.

Technical Context

This device operates as a medium-power PNP bipolar junction transistor with fixed-emitter configuration, designed for linear and saturated switching modes. Its -40V V_CEO rating supports 24V automotive rail applications, while the -250mV V_CE(sat) at -500mA ensures minimal conduction loss in high-side switch topologies.

The 100MHz f_T and 225pF C_ibo support fast turn-on/turn-off transitions (t_on = 35ns, t_off = 600ns), and its h_FE variation (300–800) across IC = -10mA to -2A enables predictable base drive sizing without active compensation.

Key Specifications

Pinout & Package

Package: SOT89 - Surface-mount plastic case with exposed emitter tab for thermal conduction; 0.05g mass; UL 94V-0 rated molding compound; moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP power switching applications.

Compared with ZTX788B and MJD2955T4G, FCX790ATA uniquely balances -40V rating, -2A capability, and SOT89 thermal efficiency-making it optimal for space-constrained 24V automotive and industrial switching where 2W dissipation must be managed without heatsinks.

Availability

FCX790ATA is available at Aetrix Electronics and suitable for automotive door modules, industrial 24V DC-DC bias control, and LED driver current regulation requiring stable component supply and RoHS-compliant manufacturing.

Supply support for FCX790ATA 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.

FCX790ATA belongs to Diodes' FCX series of high-reliability PNP power transistors, engineered specifically for automotive and industrial switching applications demanding robust V_CEO, low V_CE(sat), and AEC-Q101 qualification pathways.

FAQ

What is the maximum allowable PCB copper area to achieve the 2W power dissipation rating?

The 2W rating assumes mounting on a 40mm × 40mm × 0.6mm FR4 PCB with full coverage of 1oz single-sided copper. Reducing copper area below this de-rates power handling linearly; for example, 15mm × 15mm copper limits PD to 1W per datasheet Note 5 and 6. Thermal vias to internal ground planes further improve performance but are not included in the baseline rating.

Is FCX790ATA qualified to AEC-Q101, and what documentation supports this claim?

FCX790ATA is manufactured in IATF 16949-certified facilities and supports PPAP documentation; however, it is not pre-qualified to AEC-Q101. Customers requiring formal qualification must initiate a joint test program with Diodes Incorporated, leveraging the device's design compliance with stress test requirements outlined in the AEC-Q101 standard.

Can FCX790ATA be used in linear (non-saturated) amplifier configurations?

Yes - its h_FE stability (300–800) across -10mA to -2A and -250mV to -450mV V_CE(sat) range supports Class-A and Class-AB operation. However, linear use above 1W dissipation requires careful thermal design due to limited SOT89 thermal resistance (R_θJA ≈ 125°C/W on 15mm² copper).

What is the meaning of the "790" marking on the top of the SOT89 package?

The "790" marking is the product type code defined in Diodes' internal marking system and corresponds exclusively to the FCX790A family. It is not a date code or lot identifier; all FCX790ATA units carry this marking regardless of production batch or reel position.