Texas Instruments CSD18503KCS

Overview

CSD18503KCS from Texas Instruments is a 40V, 3.6mΩ (at V_GS = 10V), N-channel NexFET™ power MOSFET in a TO-220 package, designed for high-efficiency DC-DC conversion and synchronous rectification. It delivers 100A continuous drain current at T_C = 100°C, features ultra-low gate charge (Q_g = 30nC at 10V), and supports logic-level drive with V_GS(th) = 1.9V.

For engineers reviewing the CSD18503KCS datasheet, CSD18503KCS pinout, CSD18503KCS application, or CSD18503KCS equivalent, key selection criteria include R_DS(on) stability across temperature, avalanche energy rating (162mJ), thermal resistance (R_θJC = 0.8°C/W), and gate-drive compatibility with standard PWM controllers in high-frequency power stages.

Technical Context

This MOSFET employs a silicon-based planar trench process optimized for low Q_gd/Q_g ratio (4.6nC/30nC), enabling fast switching with reduced Miller-induced shoot-through risk. Its transconductance (g_fs = 98S) and low threshold voltage support robust turn-on under partial gate drive conditions.

The device is rated for unclamped inductive switching up to 358A pulsed drain current and operates across –55°C to +175°C junction temperature. Thermal design leverages direct case-to-heatsink conduction via the TO-220 drain-connected tab, with R_θJC tightly specified at 0.8°C/W.

Key Specifications

Pinout & Package

TO-220 plastic package with isolated mounting tab (drain-connected); 3-terminal configuration optimized for vertical heatsink mounting and manual through-hole assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IRF1404PBF and STP40NF10L, the CSD18503KCS delivers superior gate-charge efficiency (30nC vs. ≥75nC), guaranteed avalanche capability, and tighter V_GS(th) control-making it optimal for high-frequency, high-reliability power stages where thermal management and driver simplicity are critical.

Availability

CSD18503KCS is available at Aetrix Electronics and suitable for DC-DC conversion, motor control, and hot-swap protection applications requiring stable component supply, long-term industrial lifecycle support, and traceable sourcing.

Supply support for CSD18503KCS 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 specializing in analog, embedded processing, and power management technologies, with decades of leadership in high-performance power devices.

The CSD18503KCS belongs to TI's NexFET™ power MOSFET product line, engineered specifically for high-efficiency, high-frequency power conversion in servers, telecom infrastructure, and industrial motor drives.

FAQ

What is the maximum continuous drain current rating for the CSD18503KCS at 100°C case temperature?

The CSD18503KCS supports 100A continuous drain current when the case temperature (T_C) is maintained at 100°C. This rating is silicon-limited and reflects thermal equilibrium under forced-air or heatsink-cooled conditions with R_θJC = 0.8°C/W. At T_C = 25°C, the rating increases to 142A, but practical designs must respect derating curves in the datasheet.

Does the CSD18503KCS require a gate resistor for stable operation?

Yes - while the CSD18503KCS does not mandate a gate resistor, a series gate resistor (typically 2–10Ω) is recommended to dampen ringing, control dV/dt, and prevent oscillation during switching. The device's low Q_gd (4.6nC) and high g_fs (98S) make it sensitive to parasitic inductance; proper gate loop layout and resistor selection are essential for reliable CSD18503KCS performance.

Is the CSD18503KCS suitable for linear-mode operation in hot-swap circuits?

Yes - the CSD18503KCS is qualified for linear-mode use, supported by its 188W power dissipation rating, 175°C max junction temperature, and SOA curve validated up to 10ms pulses. When used in hot-swap FET applications, ensure gate drive remains within ±20V and implement thermal foldback to avoid exceeding safe operating area limits during sustained inrush events.

What is the diode forward voltage (V_SD) of the body diode in the CSD18503KCS at 75A?

The body diode forward voltage (V_SD) of the CSD18503KCS is 0.8V minimum and 1.0V typical at I_SD = 75A and T_C = 25°C. This low V_SD contributes to reduced conduction loss during dead-time conduction in synchronous rectifiers, and the diode's 60nC Q_rr and 37ns t_rr further minimize reverse recovery losses in high-frequency topologies.

How does the CSD18503KCS compare to older TO-220 MOSFETs in terms of thermal performance?

The CSD18503KCS achieves R_θJC = 0.8°C/W - among the lowest for TO-220 packages - due to optimized die attach and internal thermal path design. This is ~30% better than legacy equivalents like IRF1404 (R_θJC ≈ 1.1°C/W), enabling higher power density and relaxed heatsink requirements. The CSD18503KCS also maintains R_DS(on) stability across temperature, reducing thermal runaway risk in parallel configurations.