Texas Instruments CSD17551Q5A

Overview

CSD17551Q5A from Texas Instruments is a 30V, N-channel NexFET™ power MOSFET in a thermally enhanced 8-pin SON (5 mm × 6 mm) package, optimized as a control FET in synchronous buck converters. It delivers R_DS(on) = 7 mΩ at V_GS = 10 V, Q_g = 6.0 nC, and avalanche-rated operation for robustness in telecom and computing point-of-load applications.

For engineers reviewing the CSD17551Q5A datasheet, CSD17551Q5A pinout, CSD17551Q5A application, or CSD17551Q5A equivalent, key selection criteria include low gate charge for high-frequency switching, ultra-low on-resistance at 4.5 V gate drive, thermal resistance of 4.2°C/W (junction-to-case), and compatibility with compact 5×6 mm PCB layouts in space-constrained DC/DC modules.

Technical Context

This MOSFET employs a trench-gate silicon process to achieve ultra-low Q_g (6.0 nC) and Q_gd (1.4 nC), enabling fast switching with reduced Miller-induced turn-off delay. Its R_DS(on) remains stable across temperature-11 mΩ at 125°C (V_GS = 4.5 V)-supporting high-efficiency control-FET operation in synchronous rectification stages.

The device integrates an intrinsic body diode with V_SD = 0.8–1.0 V at I_SD = 11 A and Q_rr = 8.7 nC, minimizing reverse-recovery losses. Its 30 V V_DS rating and 31.3 mJ single-pulse avalanche energy ensure reliability under transient overvoltage conditions in non-isolated buck topologies.

Key Specifications

Pinout & Package

Package: VSONP (DQJ), 8-pin, 5 mm × 6 mm plastic SON with exposed thermal pad (bottom-side). Dimensions per TI mechanical drawing M0135-01: D1 = 4.90 mm, E = 6.00 mm, A = 1.00 mm, thermal pad area ≈ 25 mm².

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar N-channel control-FET applications.

Compared with CSD17551Q5A, CSD17573Q5B trades 2.5 mΩ higher on-resistance for 1.3 nC lower gate charge-favoring high-frequency, low-current operation-while IRF7759L2TRPBF offers broader industry familiarity but sacrifices 50% more switching loss and requires larger gate-driver capability.

Availability

CSD17551Q5A is available at Aetrix Electronics and suitable for networking point-of-load converters, server VRM control stages, and industrial PLC power supplies requiring stable component supply and long-term manufacturability.

Supply support for CSD17551Q5A 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 ICs with broad industrial, automotive, and communications market reach.

The NexFET™ power MOSFET product line was engineered specifically for high-efficiency, high-frequency DC/DC conversion-emphasizing ultra-low gate charge, minimized package inductance, and thermally optimized packaging for next-generation power delivery networks.

FAQ

What is the maximum continuous drain current for CSD17551Q5A at 25°C case temperature?

The CSD17551Q5A supports a continuous drain current of 48 A when the case temperature (T_C) is maintained at 25°C, as specified in its Absolute Maximum Ratings table. This rating assumes ideal heat sinking; actual usable current in PCB-mounted applications depends on thermal design and ambient conditions. For CSD17551Q5A, the 13.5 A rating at T_A = 25°C reflects natural convection limits on standard FR4 boards.

Does CSD17551Q5A require a gate resistor for stable operation in a 1 MHz synchronous buck converter?

CSD17551Q5A has an internal gate resistance of 1.4 Ω, which provides inherent damping to suppress gate-loop oscillation. In most 1 MHz designs with proper PCB layout (short gate traces, ground plane under gate net), no external gate resistor is required. However, if ringing persists, a 2–5 Ω surface-mount resistor in series with the gate is recommended-CSD17551Q5A's low Q_gd makes it particularly responsive to such tuning.

Can CSD17551Q5A be used as a synchronous rectifier in a 12 V input buck converter?

Yes, CSD17551Q5A is qualified for synchronous rectifier use in 12 V input buck converters due to its low R_DS(on) (7 mΩ @ 10 V), fast switching (t_f = 4.3 ns), and integrated body diode with low V_SD (0.8 V). Its 30 V V_DS rating provides sufficient margin for 12 V systems with typical overshoot, and its avalanche rating ensures robustness during transient events in CSD17551Q5A-based designs.

What is the recommended PCB land pattern for CSD17551Q5A's thermal pad?

The recommended PCB land pattern for CSD17551Q5A's exposed thermal pad follows TI's SLPA005 guidelines: a 4.9 mm × 4.5 mm central copper area with eight 0.65 mm thermal vias (minimum) connecting to inner-layer ground planes. The pattern matches dimensions F10 (4.9–5.0 mm) and F11 (4.46–4.56 mm) in the official mechanical drawing-critical for achieving the specified R_θJA = 52.3°C/W and avoiding thermal derating in CSD17551Q5A deployments.

Is CSD17551Q5A compatible with lead-free reflow profiles?

Yes, CSD17551Q5A is rated for lead-free reflow with MSL Level-1 (unlimited floor life) and peak reflow temperature of 260°C per JEDEC J-STD-020. Its SN (tin) lead finish and VSONP package are fully compatible with standard Pb-free soldering processes. No special pre-bake or handling is required before reflow-CSD17551Q5A can be placed directly from tape-and-reel into production lines meeting IPC-7095 guidelines.