Diodes Incorporated ZDT1048TA

Overview

ZDT1048TA from Diodes Incorporated is a dual NPN medium-power high-gain transistor pair in an SM-8 surface-mount package, rated for 5A continuous collector current per device, 17.5V V_CEO, and 2.75W total power dissipation with both dies active. It delivers V_CE(sat) as low as 45mV at 5A/100mA drive and h_FE up to 1200 at 10mA, enabling efficient switching in CCFL inverter and Royer oscillator circuits.

For engineers reviewing the ZDT1048TA datasheet, ZDT1048TA pinout, ZDT1048TA application, or ZDT1048TA equivalent, key selection criteria include verified dual-die thermal derating (22 mW/°C when both transistors are active), low-saturation performance under pulsed 5A loads, SM-8 footprint compatibility with 12mm tape width, and AEC-Q101 qualification readiness for automotive-grade designs.

Technical Context

The ZDT1048TA integrates two electrically isolated NPN bipolar junction transistors on a single die substrate within a thermally optimized SM-8 package. Each transistor supports independent biasing with separate base, emitter, and collector terminals, and shares common thermal mass-enabling synchronized switching while requiring careful PCB copper area design (2-inch² recommended) to maintain junction temperature below +150°C.

Its electrical behavior is characterized by high DC current gain across wide operating ranges (h_FE = 280–1200), fast switching (t_on = 120 ns, t_off = 250 ns at 4A), and robust breakdown ratings (V_CBO = 50 V, V_EBO = 5 V), making it suitable for resonant converter topologies where precise timing and low conduction loss are critical.

Key Specifications

Pinout & Package

Package: SM-8, 8-pin surface-mount molded plastic package (UL 94V-0), 6.6 mm × 7.0 mm footprint, 1.6 mm height, matte tin-plated leads, 0.117 g weight.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZDT1048TA, ZXTN2020ZTA lacks integration and thermal headroom for 5A operation, while MBT3904DW1T1G falls short in current capacity and saturation performance-neither matches the ZDT1048TA's combination of dual-die power density, low-loss switching, and automotive-ready construction.

Availability

ZDT1048TA is available at Aetrix Electronics and suitable for CCFL inverters, Royer oscillators, and automotive interior lighting systems requiring stable component supply and long-term production continuity.

Supply support for ZDT1048TA 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 ZDT series targets high-reliability power switching applications, emphasizing low-saturation transistors in compact packages for lighting, power conversion, and automotive subsystems where thermal efficiency and board-space savings are critical.

FAQ

Is ZDT1048TA qualified to AEC-Q101?

No, ZDT1048TA itself is not AEC-Q101 certified, but Diodes states it is manufactured in IATF 16949-certified facilities and supports PPAP documentation. Customers requiring formal qualification must contact Diodes directly to initiate change control and testing for specific automotive programs.

What is the maximum allowable PCB temperature rise for ZDT1048TA at 5A?

With both transistors active and 2-inch² copper area, the 45.5 °C/W R_θJA limits junction-to-ambient rise to ≤114°C at 2.75W dissipation. To stay within the +150°C max T_J, ambient must remain ≤36°C-or copper area must be increased to reduce thermal resistance.

Can ZDT1048TA replace discrete SOT-23 transistors in existing designs?

Yes, but only with layout revision: SM-8 has different pinout, larger footprint, and exposed thermal pad requiring solder paste stencil adjustment and thermal via placement. Electrical replacement is valid for I_C > 2A applications where discrete SOT-23 pairs exceed thermal limits.

Why does the datasheet state "NOT RECOMMENDED FOR NEW DESIGNS"?

Diodes issued this notice due to planned obsolescence-likely reflecting migration toward newer process nodes or integrated alternatives. However, ZDT1048TA remains in active production with full datasheet support, and Aetrix guarantees supply continuity through lifecycle management for existing designs.