Diodes Incorporated FZT788ATA

Overview

FZT788ATA from Diodes Incorporated is a PNP silicon planar medium-power high-gain transistor in SOT-223 package, rated for -15 V V_CEO, -3 A continuous collector current, and 2 W power dissipation at T_amb = 25°C; features low V_CE(sat) of -0.25 V at I_C = -1 A / I_B = -5 mA and h_FE = 400 typical at I_C = -1 A, used in battery-powered load switching and linear regulation circuits.

For engineers reviewing the FZT788ATA datasheet, FZT788ATA pinout, FZT788ATA application, or FZT788ATA equivalent, key selection criteria include verified PNP polarity, SOT-223 thermal performance, saturation voltage under pulsed and DC conditions, gain stability across -55°C to +150°C, and complementary pairing with FZT688B for push-pull designs.

Technical Context

This device operates as a medium-power PNP bipolar junction transistor optimized for linear and switching applications where low saturation voltage and high DC current gain are critical. It supports pulsed peak currents up to -8 A and maintains h_FE ≥ 150 at I_C = -6 A, enabling robust operation in battery-backed regulators and motor drive stages.

Thermal design is enabled by its SOT-223 package with exposed emitter pad, delivering 62.5°C/W junction-to-ambient (R_θJA) on FR-4 PCB with 1-in² copper pour. Safe operating area (SOA) curves confirm stable operation up to 100 ms at V_CE = -10 V / I_C = -500 mA under defined pulse conditions.

Key Specifications

Pinout & Package

SOT-223 package with molded plastic body, exposed emitter pad for thermal enhancement, and three leads: Collector (lead 1), Base (lead 2), Emitter (lead 3). Pin 4 is the thermal tab (internally connected to emitter).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZXTN25050DFH and MJD2955G, FZT788ATA delivers optimal balance of gain, saturation voltage, and SMT manufacturability for battery-powered systems operating near -12 V rails, without sacrificing thermal performance or layout density.

Availability

FZT788ATA is available at Aetrix Electronics and suitable for battery-powered load switching, linear voltage regulation, complementary output stages, and industrial level-shifting applications requiring stable component supply and consistent parametric performance across production lots.

Supply support for FZT788ATA 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 centers across Asia and manufacturing in China, Taiwan, and Malaysia.

FZT788ATA belongs to the FZT series of medium-power bipolar transistors engineered for high-efficiency switching and linear regulation in space-constrained, thermally demanding applications such as portable equipment and industrial controls.

FAQ

What is the maximum safe continuous collector current for FZT788ATA at 70°C ambient?

At T_amb = 70°C, derated continuous collector current is -2.2 A. This is calculated using the 2 W P_tot rating and R_θJA = 62.5°C/W: T_j(max) = 150°C → ΔT = 80°C → P_max = 80°C / 62.5°C/W = 1.28 W; then I_C ≈ √(P_max × R_CE(sat)^-1) yields ~2.2 A with V_CE(sat) ≈ -0.25 V.

Is FZT788ATA pin-compatible with FZT788B?

Yes - FZT788ATA and FZT788B share identical SOT-223 pinout (C-B-E-tab), electrical specifications, and thermal characteristics. The "A" suffix denotes tape-and-reel packaging per EIA-481; "B" indicates bulk packaging. No circuit redesign is needed when substituting between them.

Can FZT788ATA be used in avalanche mode?

No - FZT788ATA is not rated or characterized for avalanche energy absorption. Its absolute maximum ratings specify only V_(BR)CEO = -15 V under DC conditions. Operation beyond this voltage risks irreversible breakdown; external clamping or snubbing is required for inductive load switching.

What is the recommended minimum base resistor value when driving FZT788ATA from a 3.3 V MCU GPIO?

For reliable saturation at I_C = -1 A, assume h_FE = 100 (conservative), so I_B ≥ -10 mA. With V_BE(sat) ≈ -0.9 V and 3.3 V GPIO high level, the drop across the resistor is 3.3 V − (−0.9 V) = 4.2 V. Minimum R_B = 4.2 V / 10 mA = 420 Ω; 390 Ω is standard and preferred.