NXP Semiconductors PHM18NQ15T,518

Overview

PHM18NQ15T from NXP Semiconductors (formerly Philips Semiconductors) is an N-channel TrenchMOS™ standard-level power MOSFET in a thermally enhanced HVSON8 (QLPAK) package, rated for 150 V V_DS, 19 A continuous drain current at T_mb = 25 °C, and 75 mΩ maximum R_DS(on) at V_GS = 10 V and T_j = 25 °C. It serves as a primary-side switch in DC-to-DC converters and portable equipment power stages.

For engineers reviewing the PHM18NQ15T datasheet, PHM18NQ15T pinout, PHM18NQ15T application, or PHM18NQ15T equivalent, key selection criteria include its 2 K/W junction-to-mounting-base thermal resistance, avalanche energy rating of 170 mJ, and gate charge profile optimized for high-frequency switching in compact power supplies.

Technical Context

This device employs TrenchMOS™ technology to achieve low on-resistance and fast switching with controlled gate charge distribution: Q_g(tot) = 26.4 nC, Q_gd = 8.8 nC, and C_iss = 1150 pF at V_DS = 25 V. Its SO-8 footprint-compatible QLPAK package integrates an exposed mounting base electrically connected to the drain, enabling direct thermal coupling to PCB copper.

The PHM18NQ15T operates with a gate threshold voltage V_GS(th) of 2–4 V at 25 °C and maintains stable R_DS(on) up to 150 °C junction temperature (129–173 mΩ max), supporting robust operation in thermally constrained environments without external gate drivers.

Key Specifications

Pinout & Package

Package: HVSON8 (QLPAK), plastic thermal-enhanced very thin small outline package, no leads, 8 terminals, body dimensions 6 × 5 × 0.85 mm, with exposed mounting base electrically tied to drain terminals.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP18NF15 and IRFZ44NPBF, the PHM18NQ15T uniquely combines 150 V rating, QLPAK's 2 K/W thermal performance, and surface-mount compatibility-making it irreplaceable in space-constrained, high-input-voltage DC-DC modules where thermal management relies solely on PCB layout.

Availability

PHM18NQ15T is available at Aetrix Electronics and suitable for DC-DC converter primary-side switching, portable equipment power management, and motor drive half-bridge applications requiring stable component supply across extended production lifecycles.

Supply support for PHM18NQ15T 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, headquartered in Eindhoven, Netherlands, is a global semiconductor leader focused on secure connectivity solutions for automotive, industrial, and IoT markets.

The PHM18NQ15T belongs to NXP's TrenchMOS™ standard-level power MOSFET product line, engineered specifically for high-efficiency, high-density switched-mode power supplies in portable and industrial equipment where thermal performance and reliability under repetitive stress are critical.

FAQ

What is the maximum continuous drain current rating for PHM18NQ15T at 100 °C mounting base temperature?

The PHM18NQ15T supports 12 A continuous drain current (I_D) at T_mb = 100 °C and V_GS = 10 V, as specified in Table 3 of the datasheet. This derating reflects thermal limitations of the QLPAK package; maintaining adequate PCB copper area and airflow ensures stable operation at this current level. The PHM18NQ15T must be mounted on a minimum 200 mm² thermal pad to achieve the published 12 A rating.

Does PHM18NQ15T have avalanche capability, and how is it quantified?

Yes, the PHM18NQ15T is rated for non-repetitive drain-source avalanche energy E_DS(AL)S = 170 mJ under defined conditions: unclamped inductive load, I_D = 9.9 A, pulse width t_p = 0.16 ms, V_DD ≤ 150 V, V_GS = 10 V, and starting junction temperature of 25 °C. This specification confirms robustness against inductive switching transients in flyback and forward converters. The PHM18NQ15T leverages TrenchMOS™ structure to sustain this energy without degradation.

What is the gate threshold voltage range for PHM18NQ15T, and how does it vary with temperature?

The PHM18NQ15T has a gate-source threshold voltage V_GS(th) of 2–4 V at T_j = 25 °C, narrowing to 1.2–4.4 V across the full junction temperature range (−55 °C to +150 °C). At high temperature, the lower bound drops to 1.2 V, ensuring turn-on remains reliable under thermal stress. This behavior is confirmed in Table 5 and Figure 9 of the datasheet. Designers using the PHM18NQ15T should ensure gate drive exceeds 4.5 V to guarantee full enhancement across all operating conditions.

Can PHM18NQ15T be used as a synchronous rectifier, and what diode characteristics support this?

Yes, the PHM18NQ15T integrates a source-drain body diode with V_SD = 0.76–1.2 V at I_S = 5 A and reverse recovery time t_rr = 87 ns, making it suitable for synchronous rectification in medium-frequency DC-DC converters. Its Q_r = 162 nC and low C_oss = 187 pF further reduce switching losses during commutation. When used as a synchronous rectifier, the PHM18NQ15T must be driven with precise timing to avoid shoot-through; its gate charge profile (Q_gs = 3.9 nC, Q_gd = 8.8 nC) enables clean turn-on/turn-off control in such configurations.

What is the thermal resistance from junction to mounting base (R_th(j-mb)) for PHM18NQ15T, and how is it measured?

The PHM18NQ15T has a typical thermal resistance R_th(j-mb) = 2 K/W from junction to mounting base, as stated in Table 4. This value is derived from transient thermal impedance measurements per Figure 4 and assumes the mounting base is soldered to a solid copper thermal pad on the PCB. Unlike case-to-ambient metrics, R_th(j-mb) isolates package conduction performance independent of system-level airflow or heatsinking-enabling accurate junction temperature prediction using T_j = T_mb + (P_diss × 2 K/W). This parameter is critical for validating thermal design before prototyping the PHM18NQ15T.