Texas Instruments CSD19538Q3AT

Overview

CSD19538Q3AT from Texas Instruments is a 100V N-Channel NexFET™ Power MOSFET in an 8-pin VSONP (DNH) package, optimized for low-conduction-loss switching in Power over Ethernet (PoE) power sourcing equipment (PSE). It delivers 49 mΩ R_DS(on) at V_GS = 10 V, 4.3 nC total gate charge, and avalanche-rated ruggedness for reliable operation in high-reliability DC-DC and hot-swap circuits.

For engineers reviewing the CSD19538Q3AT datasheet, CSD19538Q3AT pinout, CSD19538Q3AT application, or CSD19538Q3AT equivalent, this page provides verified electrical parameters, thermal performance data, package layout guidance, and real-world PoE PSE and motor control use cases - all confirmed against TI's SLPS583B production datasheet (October 2025 revision).

Technical Context

This MOSFET employs a silicon-limited design with ultra-low Q_g (4.3 nC) and Q_gd (0.8 nC) to minimize switching losses and enable high-frequency operation in isolated flyback and active clamp forward converters. Its 3.3 mm × 3.3 mm exposed-pad VSONP package achieves R_θJC = 5.5°C/W and R_θJA = 55°C/W on standard FR4 PCBs.

The device features a 3.2 V gate threshold voltage (V_GS(th)), 100 V drain-source breakdown rating, and integrated body diode with 0.85 V forward voltage at 5 A - supporting synchronous rectification and bidirectional current handling in half-bridge motor drive stages.

Key Specifications

Pinout & Package

Package: VSONP (DNH), 8-pin plastic no-lead with exposed thermal pad (3.3 mm × 3.3 mm footprint, 0.9 mm max height). Requires soldering of thermal pad to PCB copper for thermal and mechanical integrity per TI SLUA271 guidelines.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar N-Channel power MOSFET applications.

Compared with IRF7478PBF and SiR872DP, the CSD19538Q3AT offers optimal balance of compact 3.3 mm × 3.3 mm footprint, 4.3 nC gate charge for high-frequency PoE PSE designs, and guaranteed avalanche capability - making it uniquely suited for space- and reliability-critical IEEE 802.3bt implementations.

Availability

CSD19538Q3AT is available at Aetrix Electronics and suitable for Power over Ethernet (PoE) power sourcing equipment, industrial motor control interfaces, and hot-swap controller modules requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for CSD19538Q3AT 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

Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets since 1930.

The CSD19538Q3AT belongs to TI's NexFET™ Power MOSFET product line, engineered specifically for high-efficiency, high-density power conversion in PoE, motor control, and hot-swap applications where low gate charge and thermal performance are critical.

FAQ

What is the maximum continuous drain current for CSD19538Q3AT at 25°C ambient temperature?

The CSD19538Q3AT supports 4.9 A continuous drain current under ambient conditions (T_A = 25°C) with typical R_θJA = 55°C/W on a 1-in², 2 oz Cu FR4 PCB. At case temperature T_C = 25°C, it sustains 14 A continuously - confirming its suitability for thermally constrained PoE PSE modules where heatsinking is limited.

Does CSD19538Q3AT have avalanche capability, and what is its rated energy?

Yes, the CSD19538Q3AT is fully avalanche rated per TI's production test. Its single-pulse avalanche energy (E_AS) is 8.1 mJ when tested at I_D = 12.7 A, L = 0.1 mH, and R_G = 25 Ω - a key specification enabling robust hot-plug operation in Power over Ethernet systems without external clamping components.

What is the gate threshold voltage range for CSD19538Q3AT, and how does it vary with temperature?

The CSD19538Q3AT has a gate threshold voltage (V_GS(th)) range of 2.8 V to 3.8 V at T_A = 25°C, with a typical value of 3.2 V. As temperature increases, V_GS(th) decreases linearly - dropping to ~2.4 V at 125°C - which must be accounted for in gate drive design to ensure full enhancement across the full –55°C to +150°C operating junction range.

Is CSD19538Q3AT compatible with lead-free reflow processes, and what is its MSL rating?

Yes, the CSD19538Q3AT is RoHS compliant, halogen free, and qualified for lead-free reflow. It carries an MSL Level-1 rating per JEDEC J-STD-020, with unlimited floor life and peak reflow temperature tolerance up to 260°C - enabling compatibility with standard Pb-free assembly lines without baking or special handling.

What package type and dimensions does CSD19538Q3AT use, and is thermal pad soldering required?

The CSD19538Q3AT uses the VSONP (DNH) 8-pin no-lead package measuring 3.3 mm × 3.3 mm with 0.9 mm maximum height. Its exposed thermal pad is mandatory for both thermal performance (R_θJC = 5.5°C/W) and mechanical reliability - TI requires soldering the pad to a minimum 1-in², 2 oz Cu PCB area per SLUA271 layout guidelines.