Texas Instruments CSD17581Q3AT

Overview

CSD17581Q3AT from Texas Instruments is a 30-V, 3.2-mΩ N-channel NexFET™ power MOSFET in an 8-pin SON (VSONP-DNH) package, optimized as a control FET in high-frequency synchronous buck converters for telecom and computing point-of-load applications, with 20 nC total gate charge at 4.5 V and avalanche-rated operation.

For engineers reviewing the CSD17581Q3AT datasheet, CSD17581Q3AT pinout, CSD17581Q3AT application, or CSD17581Q3AT equivalent, key selection criteria include R_DS(on) vs. temperature stability, low Q_gd/Q_g ratio for switching loss minimization, thermal resistance (R_θJC = 2°C/W), and compatibility with 4.5-V gate drive in compact DC/DC designs.

Technical Context

This device employs a silicon-limited, trench-based N-channel MOSFET structure with integrated source-drain diode, designed for unidirectional high-side or low-side switching in synchronous rectification topologies. Its gate threshold voltage (1.3 V typ.) enables robust turn-on with standard logic-level drivers, while low output capacitance (C_oss = 342–445 pF) supports fast switching up to 1 MHz.

The exposed thermal pad and 2°C/W junction-to-case thermal resistance enable efficient heat transfer to PCB copper, critical for sustained 60-A continuous drain current at T_C = 25°C. Dynamic parameters-including 4.0 nC Q_gd, 12 ns t_d(on), and 10 ns t_f-are characterized under V_DS = 15 V, I_D = 16 A, and zero-gate-resistance conditions per JEDEC JESD24-11.

Key Specifications

Pinout & Package

Package: VSONP (DNH) 3.3 mm × 3.3 mm × 0.9 mm plastic no-lead package with exposed thermal pad (Pin 9). Requires soldering of thermal pad to PCB for rated thermal performance and mechanical reliability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CSD17581Q3AT, CSD17579Q3A trades marginally lower Q_g for higher R_DS(on), while IRLHS6342TRPBF offers lower on-resistance but sacrifices avalanche ruggedness and thermal pad integration-making CSD17581Q3AT the balanced choice for robust, thermally constrained POL and motor control designs.

Availability

CSD17581Q3AT is available at Aetrix Electronics and suitable for point-of-load converters, motor control half-bridges, server VRMs, and hot-swap protection circuits requiring stable component supply, consistent parametric performance, and long-term industrial lifecycle support.

Supply support for CSD17581Q3AT 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, specializing in analog, embedded processing, and power management technologies for industrial, automotive, and communications markets.

CSD17581Q3AT belongs to TI's NexFET™ power MOSFET product line, engineered specifically for high-efficiency, high-frequency DC/DC conversion in space-constrained computing and networking infrastructure.

FAQ

What is the maximum continuous drain current for CSD17581Q3AT at 100°C case temperature?

The CSD17581Q3AT supports 21 A continuous drain current at T_C = 100°C, derated from its 60-A rating at T_C = 25°C per the absolute maximum ratings table. This value reflects package thermal limitation-not silicon capability-and assumes proper PCB copper area and airflow per TI's recommended layout guidelines. The CSD17581Q3AT maintains stable R_DS(on) up to 125°C junction temperature, enabling reliable operation in thermally demanding environments.

Does CSD17581Q3AT require a gate resistor for stable switching in a 500-kHz synchronous buck converter?

Yes, a small external gate resistor (typically 1–5 Ω) is recommended for the CSD17581Q3AT in 500-kHz buck converters to dampen gate ringing caused by PCB trace inductance interacting with its 1.8–3.6 Ω internal gate resistance and 2800–3640 pF input capacitance. TI's evaluation data shows that 2.2 Ω optimizes EMI and switching loss trade-offs without compromising t_d(on) (12 ns) or t_f (10 ns) performance. The CSD17581Q3AT's low Q_gd further reduces sensitivity to gate drive impedance variations.

Can CSD17581Q3AT be used as a replacement for CSD17581Q3A in existing designs?

Yes, the CSD17581Q3AT is functionally and electrically identical to CSD17581Q3A, differing only in tape-and-reel packaging (250 vs. 2500 units per reel) and part marking. Both share identical VSONP (DNH) 8-pin package dimensions, thermal pad layout, pinout, and full electrical specifications including R_DS(on), Q_g, and avalanche rating. No PCB or schematic changes are required when substituting CSD17581Q3AT for CSD17581Q3A in production or prototyping.

What is the recommended PCB land pattern for the thermal pad of CSD17581Q3AT?

Texas Instruments specifies a solid 3.1 mm × 3.1 mm copper pad for the CSD17581Q3AT's exposed thermal pad, with 8–12 thermal vias (0.3 mm diameter, spaced ≤1 mm apart) connecting to inner-layer ground or power planes. The recommended stencil aperture is 76% coverage (3.1 mm × 3.1 mm opening) using a 0.125-mm-thick stencil. This layout achieves the rated 2°C/W R_θJC and prevents solder voiding-critical for maintaining the CSD17581Q3AT's 60-A current capability and thermal reliability.

Is CSD17581Q3AT qualified for automotive applications per AEC-Q101?

No, the CSD17581Q3AT is not AEC-Q101 qualified. It is specified for industrial and computing applications with operating junction temperature range of –55°C to 150°C and is rated for commercial/industrial use only. While its absolute maximum ratings and thermal performance meet many automotive sub-system requirements, TI does not certify or guarantee CSD17581Q3AT for automotive use. For AEC-Q101-compliant alternatives, engineers should consult TI's automotive-qualified NexFET™ portfolio, such as the CSD17573Q5B.