Diodes Incorporated DI9405T

Overview

DI9405T from Diodes Incorporated is a single P-channel enhancement-mode MOSFET designed for high-efficiency DC-DC conversion and load switching in space-constrained industrial and automotive power systems. It features -20 V V_DSS, 0.075 Ω R_DS(on) @ V_GS = -10 V, 4.3 A continuous drain current at 25°C, and SO-8 surface-mount packaging - enabling compact synchronous buck converter high-side switches and reverse-polarity protection circuits.

For engineers reviewing the DI9405T datasheet, DI9405T pinout, DI9405T application, or DI9405T equivalent, key selection criteria include verified R_DS(on) vs. temperature behavior, gate charge (Q_g = 40 nC), transient thermal impedance curves, and SO-8 drain-connected thermal pad layout compatibility with 1 in² copper pour.

Technical Context

This MOSFET operates as a normally-off P-channel switch requiring negative gate drive relative to source. Its low R_DS(on) and fast switching (t_r = 24 ns typ., t_f = 30 ns typ.) support high-frequency (>500 kHz) PWM control in buck regulators and hot-swap controllers. The integrated body diode has V_SD = -0.78 V @ I_S = -1.25 A and t_rr = 80 ns, suitable for freewheeling in non-synchronous topologies.

Thermal performance is defined by R_ΘJC = 25°C/W and R_ΘJA = 50°C/W with 1 in² 2 oz. copper - confirming its suitability for thermally demanding applications where junction temperature must remain ≤150°C under sustained 3.3 A loads at 70°C ambient.

Key Specifications

Pinout & Package

DI9405T uses an SO-8 plastic package with exposed drain thermal pad (pins 1–4 and 6–8 are drain-connected; pin 5 is gate; pins 2 and 3 are source). This configuration provides low-inductance, high-current drain paths and direct thermal coupling to PCB copper.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DMN2013LFG-7 and SI2301-CDS-T1-GE3, DI9405T delivers optimal balance of gate-drive flexibility (supports -4.5 V and -10 V), thermal robustness (SO-8 with exposed drain), and cost for 2–4 A industrial load switching - making it the default choice where board area and thermal margin are constrained but not extreme.

Availability

DI9405T is available at Aetrix Electronics and suitable for reverse polarity protection, hot-swap control, synchronous buck high-side switching, and industrial PLC load switching requiring stable component supply and long-term production continuity.

Supply support for DI9405T 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 Taiwan and China.

The DI9405T belongs to Diodes' PowerMOS™ portfolio, engineered specifically for high-reliability industrial and automotive power management where low R_DS(on), robust SO-8 thermal performance, and AEC-Q101 stress qualification are mandatory.

FAQ

What is the maximum safe operating area (SOA) for DI9405T at 100 µs pulse width?

At 100 µs pulse width and T_j = 25°C, DI9405T supports up to -12 V V_DS and -8 A I_D in single-pulse mode (Fig. 5). This corresponds to 96 W instantaneous power, limited by both R_DS(on) and transient thermal impedance. Derating is required above 25°C ambient per the normalized r(t) curve in Fig. 6.

Can DI9405T be used in linear regulation mode?

No - DI9405T is not characterized or rated for linear (ohmic) operation. Its Safe Operating Area curve shows no DC or long-pulse capability below 10 ms, and R_DS(on) variation with temperature introduces instability in pass-element configurations. It is strictly intended for switched-mode applications.

Is the SO-8 package lead-free and RoHS compliant?

Yes - DI9405T is manufactured in a lead-free, halogen-free, RoHS-compliant SO-8 package per Diodes Incorporated's PPAP documentation (Package Code: SO-8, Material Set: MSL1, Pb-Free Reflow Profile: J-STD-020D).

Does DI9405T require a gate resistor for ESD protection?

No external gate resistor is required solely for ESD protection - the device incorporates internal gate protection diodes rated to ±20 V. However, a 10–100 Ω series gate resistor is recommended to dampen ringing and limit peak current during fast switching, especially in high-dV/dt environments like motor drives.