Diodes Incorporated DI9400T

Overview

DI9400T from Diodes Incorporated is a single P-channel enhancement-mode MOSFET designed for high-side load switching and power management in DC-DC converters, battery protection circuits, and hot-swap applications. It features -30 V V_DSS, 0.11 Ω R_DS(ON) @ V_GS = -10 V, ±3.4 A continuous drain current, and SO-8 package with exposed drain pad for thermal performance.

For engineers reviewing the DI9400T datasheet, DI9400T pinout, DI9400T application, or DI9400T equivalent, key selection criteria include gate threshold voltage (-1.0 to -2.8 V), normalized R_DS(ON) vs. temperature behavior, transient thermal impedance curves, and diode recovery characteristics (t_rr = 100 ns) for synchronous rectification use cases.

Technical Context

This device operates as a normally-off P-channel switch controlled by negative gate-source voltage. Its high cell density DMOS structure enables low on-resistance while maintaining robust avalanche energy rating and fast switching (t_f = 8.0–50 ns, t_r = 21–40 ns) under pulsed conditions (≤300 µs, ≤2% duty cycle).

Thermal design is critical: R_JA varies from 50°C/W (1 in² 2 oz Cu) to 125°C/W (0.006 in² 2 oz Cu), with fixed R_JC = 25°C/W referenced to the drain solder mounting surface - confirming its suitability for PCB-level thermal optimization in space-constrained industrial power modules.

Key Specifications

Pinout & Package

DI9400T uses an SO-8 plastic package with exposed drain pad (pins 1–4 and 5–8 are source and gate terminals respectively; pins 7 and 8 internally connected to drain and thermally tied to the exposed pad). The case reference for thermal resistance is the solder mounting surface of the drain pins.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar P-channel MOSFET switching applications.

Compared with DMG3415L-7 and SI2305DS-T1-E3, DI9400T uniquely balances -30 V rating, SO-8 thermal capability, and 3.4 A current handling - making it the only option among the three qualified for 24 V industrial control and automotive body electronics without derating.

Availability

DI9400T is available at Aetrix Electronics and suitable for automotive body control modules, industrial PLC output stages, battery protection circuits, and hot-swap controller interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for DI9400T 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 facilities in China, Taiwan, and the U.S.

The DI9400T belongs to Diodes' high-reliability power MOSFET product line, engineered specifically for robust high-side switching in harsh-environment applications including automotive, industrial automation, and medical power systems.

FAQ

What is the recommended gate drive voltage range for reliable switching of DI9400T?

The DI9400T specifies V_GS(th) between -1.0 V and -2.8 V, with full enhancement achieved at -10 V. For robust operation across temperature, apply -4.5 V to -10 V gate drive - avoiding -20 V absolute maximum to prevent gate oxide stress. Gate drive must be referenced to source, not ground, in high-side configurations.

Can DI9400T be used in synchronous rectification applications?

No - DI9400T is not optimized for synchronous rectification. Its body diode has t_rr = 100 ns and V_SD = -0.8 to -1.3 V, which introduces significant reverse recovery loss compared to dedicated synchronous rectifier MOSFETs with <30 ns t_rr and optimized charge balancing.

How does PCB copper area affect DI9400T's thermal performance?

Thermal resistance R_JA changes directly with copper area: 1 in² 2 oz Cu yields R_JA = 50°C/W (2.5 W max), while 0.006 in² yields R_JA = 125°C/W (1.0 W max). The exposed drain pad must be fully soldered to internal or external copper planes - thermal vias under the pad improve heat transfer to inner layers.

Is DI9400T suitable for linear mode (active region) operation?

DI9400T is rated for switching operation only. Its Safe Operating Area (SOA) curve (Fig. 5) shows limited linear-mode capability: at V_DS = -10 V, maximum pulse current drops to ~1.5 A for 10 ms pulses. Continuous linear use risks thermal runaway due to positive temperature coefficient of R_DS(ON).