Texas Instruments CSD18511KTT

Overview

CSD18511KTT from Texas Instruments is a 40V N-Channel NexFET™ Power MOSFET in D2PAK (TO-263) package, featuring 2.1 mΩ R_DS(on) at V_GS = 10 V, 63.9 nC total gate charge, and avalanche-rated operation. It serves as a high-efficiency power switch in secondary-side synchronous rectification and motor control circuits where low conduction and switching losses are critical.

For engineers reviewing the CSD18511KTT datasheet, CSD18511KTT pinout, CSD18511KTT application, or CSD18511KTT equivalent, key selection criteria include its 110 A continuous drain current (package-limited), 0.8 °C/W junction-to-case thermal resistance, 156 mJ single-pulse avalanche energy, and D2PAK thermal pad layout compatibility for high-power PCB designs.

Technical Context

This MOSFET employs a silicon-limited design optimized for high-current, low-voltage DC/DC conversion stages. Its low Q_gd/Q_g ratio (9.7 nC / 63.9 nC) supports fast, controlled switching with reduced Miller-induced turn-on risk, while the exposed thermal pad enables efficient heat transfer to the PCB.

The device operates across –55°C to 175°C junction temperature range and sustains 400 A pulsed drain current under defined conditions. Its 0.9–1.0 V body diode forward voltage at 100 A and 62 nC reverse recovery charge support high-frequency synchronous rectifier performance with minimal commutation loss.

Key Specifications

Pinout & Package

D2PAK (TO-263) plastic package with exposed thermal pad on underside; 3-pin configuration (Drain, Gate, Source) with Pin 1 = Gate, Pin 2 = Drain, Pin 3 = Source. Thermal pad must be soldered to PCB copper for rated power dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IRF1404ZPBF and STL220N4F7AG, the CSD18511KTT delivers optimal balance of low R_DS(on), moderate Q_g, proven avalanche ruggedness, and industry-standard D2PAK thermal management-making it preferred for high-reliability 40 V synchronous rectification and motor drive designs.

Availability

CSD18511KTT is available at Aetrix Electronics and suitable for server VRMs, industrial motor drives, telecom power supplies, and automotive auxiliary power modules requiring stable component supply and long-term manufacturability.

Supply support for CSD18511KTT 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.

The CSD18511KTT belongs to TI's NexFET™ Power MOSFET product line, engineered specifically for high-efficiency, high-current power conversion in compact form factors where thermal performance and switching fidelity are critical.

FAQ

What is the maximum continuous drain current rating for the CSD18511KTT?

The CSD18511KTT has a continuous drain current rating of 110 A when limited by the D2PAK package thermal capability at T_C = 25°C. At elevated case temperatures (e.g., 100°C), the silicon-limited current drops to 137 A, but package derating governs practical design limits. This value assumes proper PCB copper area and thermal pad soldering per TI's SLMA002 layout guidelines.

Does the CSD18511KTT support logic-level gate drive?

Yes, the CSD18511KTT supports logic-level gate drive with a typical threshold voltage (V_GS(th)) of 1.8 V and guaranteed turn-on at V_GS ≥ 4.5 V. Its R_DS(on) is specified at both 4.5 V (3.2 mΩ) and 10 V (2.1 mΩ), making it compatible with 3.3 V and 5 V microcontroller outputs when paired with appropriate gate buffering.

What is the significance of the avalanche rating for the CSD18511KTT?

The CSD18511KTT is fully avalanche-rated with E_AS = 156 mJ (ID = 56 A, L = 0.1 mH, R_G = 25 Ω). This means it can safely absorb inductive energy during unclamped switching events-such as motor phase short-circuits or transformer leakage spikes-without catastrophic failure, enhancing system reliability in motor control and power supply designs.

How does the D2PAK package of the CSD18511KTT impact thermal design?

The D2PAK (TO-263) package of the CSD18511KTT features an exposed thermal pad that must be soldered to a large PCB copper area. With R_θJC = 0.8 °C/W, this enables direct heat transfer from the die to the board, allowing >150 W power dissipation when coupled to internal planes or external heatsinks-significantly outperforming TO-220 or SO-8 alternatives in high-current applications.

Can the CSD18511KTT be used in synchronous rectifier applications at frequencies above 300 kHz?

Yes, the CSD18511KTT is suitable for synchronous rectification up to 500 kHz due to its low Q_gd/Q_g ratio (9.7 nC / 63.9 nC), fast switching times (t_d(off) = 17 ns, t_f = 3 ns), and low output capacitance (C_oss = 591 pF typ). These characteristics minimize switching loss and improve light-load efficiency in high-frequency LLC and resonant converters using the CSD18511KTT.