Texas Instruments CSD17581Q5A

Overview

CSD17581Q5A from Texas Instruments is a 30-V, 2.9-mΩ N-channel NexFET™ power MOSFET in a thermally enhanced 8-pin SON (VSONP-DQJ) 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 123-A silicon-limited continuous drain current at 25°C.

For engineers reviewing the CSD17581Q5A datasheet, CSD17581Q5A pinout, CSD17581Q5A application, or CSD17581Q5A equivalent, key selection criteria include R_DS(on) vs. V_GS behavior at 4.5 V and 10 V, gate charge profile for PWM efficiency, thermal resistance (R_θJC = 1.5°C/W), avalanche energy rating (76 mJ), and compatibility with 5-mm × 6-mm PCB land patterns requiring exposed thermal pad soldering.

Technical Context

This device employs a trench-gate silicon process to achieve low Q_g (20 nC @ 4.5 V) and low Q_gd (4.0 nC), enabling fast switching with reduced Miller-induced turn-off delay. Its R_DS(on) of 2.9 mΩ @ V_GS = 10 V and 3.5 mΩ @ V_GS = 4.5 V supports efficient operation in 5-V and 12-V gate drive systems.

The 8-pin VSONP (DQJ) package integrates an exposed thermal pad and three parallel source terminals (pins 4, 7, 8) plus two parallel drain terminals (pins 1, 2, 3), delivering low package inductance and R_θJA = 50°C/W on 1-in² 2-oz Cu - critical for high-current, high-density DC/DC designs where thermal management and switching loss dominate system efficiency.

Key Specifications

Pinout & Package

The CSD17581Q5A uses an 8-pin VSONP (DQJ) plastic package measuring 5.0 mm × 6.0 mm × 1.1 mm max height, featuring an exposed thermal pad (pin 5) that must be soldered to PCB for thermal and mechanical integrity. The package supports high-current routing via multiple paralleled terminals.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IRF7759L2TRPBF and DMT6009LPS-13, the CSD17581Q5A delivers superior thermal performance via its soldered thermal pad and lowest Q_gd, making it optimal for high-power-density, high-frequency buck converters where thermal headroom and switching fidelity are critical.

Availability

CSD17581Q5A is available at Aetrix Electronics and suitable for telecom point-of-load converters, server VRM control stages, and industrial PLC auxiliary supplies requiring stable component supply, long-term manufacturability, and RoHS-compliant packaging.

Supply support for CSD17581Q5A 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 with over 90 years of innovation in industrial, automotive, and communications markets.

The CSD17581Q5A belongs to TI's NexFET™ power MOSFET product line, engineered specifically for high-efficiency, high-frequency DC/DC conversion in space-constrained infrastructure equipment where low Q_g, low R_DS(on), and thermal reliability are primary design drivers.

FAQ

What is the maximum continuous drain current rating for the CSD17581Q5A at 100°C case temperature?

The CSD17581Q5A has a continuous drain current rating of 60 A at T_C = 100°C, derated from its 123-A silicon-limited rating at 25°C. This value reflects package thermal limits under real-world PCB mounting conditions and is validated per JEDEC JESD51-2 standards using a 1-in² 2-oz Cu pad. The CSD17581Q5A maintains safe operation within its SOA curve up to this current when R_θJC = 1.5°C/W is achieved.

Does the CSD17581Q5A require a gate resistor for stable operation in a 1-MHz synchronous buck converter?

Yes - while the CSD17581Q5A's low Q_gd (4.0 nC) improves controllability, a small gate resistor (typically 1–5 Ω) is recommended to dampen parasitic oscillation caused by PCB trace inductance interacting with C_iss (3640 pF). TI's reference design SLVA672 confirms stable 1-MHz operation with 2.2-Ω series gate resistance and Kelvin-connected gate-source return path for the CSD17581Q5A.

Can the CSD17581Q5A be used with 4.5-V gate drive in a 3.3-V output buck converter?

Yes - the CSD17581Q5A specifies R_DS(on) = 3.5 mΩ at V_GS = 4.5 V and ID = 16 A, and its V_GS(th) (1.3 V typ) ensures full enhancement well below 4.5 V. In 3.3-V output designs, this enables efficient operation with standard 5-V gate drivers without level-shifting, provided gate drive rise/fall times remain <20 ns to minimize transition losses.

What is the recommended PCB land pattern for the thermal pad of the CSD17581Q5A?

Texas Instruments recommends a 4.9 mm × 4.46 mm solder mask-defined thermal pad with 8 × 0.675-mm thermal vias (0.3-mm drill, tented on backside) centered under the CSD17581Q5A's exposed pad. Per SLUA271, this achieves R_θJC ≤ 1.5°C/W and prevents solder voiding; stencil aperture should be 70% open area (e.g., 0.125-mm thick stencil with 0.45-mm × 0.45-mm square openings).

Is the CSD17581Q5A suitable for avalanche energy handling in non-synchronous flyback designs?

Yes - the CSD17581Q5A is fully avalanche-rated with E_AS = 76 mJ (ID = 39 A, L = 0.1 mH, R_G = 25 Ω), verified per JEDEC JESD24-1. This makes it suitable for ruggedized flyback or forward converters where the MOSFET absorbs transformer leakage energy, provided peak avalanche current stays within the SOA curve and pulse duration remains ≤100 μs per datasheet Section 5.3.