NXP Semiconductors PHD55N03LTA,118

Overview

PHD55N03LTA from NXP Semiconductors (formerly Philips Semiconductors) is an N-channel logic-level TrenchMOS™ power MOSFET in SOT428 (D-PAK) package, rated for 25 V V_DS, 55 A I_D (DC at T_mb = 25 °C), and 15–18 mΩ R_DS(on) at V_GS = 5 V. It serves as a high-efficiency synchronous rectifier or main switch in high-frequency DC–DC converters on computer motherboards.

For engineers reviewing the PHD55N03LTA datasheet, PHD55N03LTA pinout, PHD55N03LTA application, or PHD55N03LTA equivalent, key selection criteria include its logic-level gate drive compatibility (V_GS(th) = 1.0–2.0 V), low R_DS(on) at 5 V, avalanche ruggedness (60 mJ), thermal resistance (R_th(j-mb) = 1.75 K/W), and D-PAK surface-mount footprint with isolated mounting base.

Technical Context

This device uses TrenchMOS™ technology to achieve low on-resistance and fast switching-td(on) ≤15 ns, tr ≤80 ns-with gate charge Q_g(tot) = 20 nC and Miller charge Q_gd = 7 nC. Its source-drain diode supports bidirectional current (I_S = 55 A DC) and exhibits V_SD = 0.95–1.2 V at I_S = 25 A.

Designed for operation up to T_j = 175 °C, it features ±20 V V_GS rating, 25 V V_(BR)DSS, and robust avalanche capability under unclamped inductive load conditions (E_DS(AL)S = 60 mJ). Thermal performance is optimized via direct die-to-mounting-base conduction path (R_th(j-mb) = 1.75 K/W).

Key Specifications

Pinout & Package

The PHD55N03LTA is housed in a SOT428 (D-PAK) plastic surface-mount package with isolated mounting base connected internally to the drain terminal. Pin 2 is not electrically accessible per datasheet note [1].

Key Features

Applications

Equivalent & Alternatives

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

Compared with IRF7470PBF and STP55NF03L, the PHD55N03LTA uniquely combines D-PAK surface-mount compatibility, 55 A current capacity, and 1.75 K/W junction-to-mounting-base thermal resistance-making it optimal for high-density, high-current motherboard and server VRM designs where thermal management and layout efficiency are co-prioritized.

Availability

PHD55N03LTA is available at Aetrix Electronics and suitable for computer motherboard VRMs, server power supplies, industrial motor drives, and telecom DC–DC converters requiring stable component supply and long-term lifecycle support.

Supply support for PHD55N03LTA 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

NXP Semiconductors is a global semiconductor leader focused on secure connectivity solutions for automotive, industrial, and IoT applications.

The PHD55N03LTA belongs to NXP's legacy TrenchMOS™ logic-level power MOSFET family, engineered specifically for high-efficiency, high-frequency DC–DC conversion in computing and communications infrastructure.

FAQ

What is the maximum continuous drain current for PHD55N03LTA at 100 °C mounting base temperature?

The PHD55N03LTA supports 38 A continuous drain current (I_D) at T_mb = 100 °C and V_GS = 5 V, as specified in Table 3 "Limiting values." This derating reflects thermal constraints of the SOT428 package and must be verified against actual board-level thermal design using the normalized I_der curve in Figure 2. The PHD55N03LTA maintains safe operation within this limit when mounted on a minimum-footprint PCB with adequate copper pour.

Does PHD55N03LTA have avalanche capability, and how is it characterized?

Yes, the PHD55N03LTA is rated for non-repetitive drain-source avalanche energy E_DS(AL)S = 60 mJ under defined test conditions: unclamped inductive load, I_D = 25 A, t_p = 0.1 ms, V_DD = 15 V, R_GS = 50 Ω, V_GS = 5 V, and starting T_j = 25 °C. This value is confirmed in Table 3 and validates its use in circuits subject to inductive switching transients. The PHD55N03LTA does not specify repetitive avalanche rating.

What is the gate-source threshold voltage range for PHD55N03LTA across temperature?

The PHD55N03LTA has a gate-source threshold voltage V_GS(th) of 1.0–2.0 V at T_j = 25 °C, 0.5–? V at T_j = 175 °C (min only specified), and up to 2.3 V at T_j = −55 °C. This wide operational window ensures reliable turn-on across industrial temperature ranges while maintaining noise immunity. All V_GS(th) values are measured at I_D = 1 mA and V_DS = V_GS, per Table 5. The PHD55N03LTA remains fully logic-compatible down to 1 V gate drive at room temperature.

Can PHD55N03LTA be used with 3.3 V gate drive in practice?

Yes-the PHD55N03LTA's V_GS(th) min = 1.0 V and typical R_DS(on) = 15 mΩ at V_GS = 5 V confirm strong enhancement-mode behavior at 3.3 V. While R_DS(on) increases versus 5 V (not explicitly tabulated at 3.3 V), the device achieves usable conduction (I_D > 20 A) with 3.3 V drive in real-world VRM applications. Designers should verify thermal margin using the R_DS(on) vs. T_j curve in Figure 8. The PHD55N03LTA is routinely deployed with 3.3 V gate drivers in motherboard designs.

Is the mounting base of PHD55N03LTA electrically isolated or connected to a terminal?

The mounting base of the PHD55N03LTA is electrically connected to the drain terminal, as confirmed in the pinning diagram (Table 1) and package outline (Figure 16). This internal tie enables direct thermal coupling to heatsinks while requiring careful PCB isolation of the drain net. Pin 2 is inaccessible and serves only as an internal drain connection point-no external solder joint is intended. The PHD55N03LTA's mounting base must be treated as a live high-current drain node in layout and safety analysis.