NXP Semiconductors PHX18NQ20T,127

Overview

PHX18NQ20T from NXP Semiconductors (formerly Philips Semiconductors) is an N-channel enhancement-mode TrenchMOS™ power MOSFET in SOT186A (TO-220F) package, rated for 200 V V_DS, 8.2 A continuous drain current at 25 °C, and 130–180 mΩ R_DS(on) at V_GS = 10 V and T_j = 25 °C. It serves as a high-efficiency switching element in off-line SMPS primary-side switches and DC–DC converter low-side drivers.

For engineers reviewing the PHX18NQ20T datasheet, PHX18NQ20T pinout, PHX18NQ20T application, or PHX18NQ20T equivalent, key selection criteria include its isolated tab design enabling direct heatsink mounting without insulation hardware, 2500 V_RMS isolation rating, and fast switching with 3 ns turn-on / 92 ns turn-off times under resistive load conditions.

Technical Context

This device implements TrenchMOS™ technology to achieve low on-state resistance and reduced gate charge (Q_g(tot) = 40 nC), supporting high-frequency operation in hard-switched topologies. Its thermal resistance from junction to heatsink is 4.17 K/W, and it features an integrated source-drain diode with 130 ns reverse recovery time and 0.8 µC recovered charge.

The PHX18NQ20T operates across −55 °C to +150 °C junction temperature range, with gate-source threshold voltage (V_GS(th)) specified from 2–4 V at 25 °C and down to 1.2 V at 150 °C-enabling stable turn-on margin under thermal stress. Its 200 V breakdown voltage and ±20 V gate-source rating support robust operation in 115/230 V AC-input power supplies.

Key Specifications

Pinout & Package

SOT186A (TO-220F) plastic single-ended package with isolated heatsink tab, 3 leads, and one mounting hole. The isolated tab allows direct mechanical and thermal attachment to a heatsink without electrical insulation hardware.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP18NF20 and IRF640NPBF, the PHX18NQ20T delivers superior thermal integration via its isolated tab and lower R_DS(on), making it uniquely suited for space-constrained, safety-certified AC/DC power supplies where layout simplicity and reliability are critical.

Availability

PHX18NQ20T is available at Aetrix Electronics and suitable for off-line switched-mode power supplies, television/computer monitor power supplies, and DC–DC converters requiring stable component supply, long-term lifecycle support, and certified isolation performance.

Supply support for PHX18NQ20T 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 formed from the spin-off of Philips Semiconductors in 2006, specializing in high-performance analog, logic, and power management solutions for automotive, industrial, and consumer markets.

The PHX18NQ20T belongs to NXP's legacy TrenchMOS™ power MOSFET product line, engineered specifically for high-efficiency, high-reliability AC/DC and DC/DC conversion in safety-critical power supply applications.

FAQ

What is the maximum continuous drain current rating for PHX18NQ20T at 100 °C heatsink temperature?

The PHX18NQ20T supports 5.2 A continuous drain current (I_D) at T_hs = 100 °C and V_GS = 10 V, as specified in Table 3 (Limiting Values). This derating reflects thermal constraints of the SOT186A package and ensures safe operation within the 150 °C maximum junction temperature limit. Designers must verify PCB copper area and airflow to sustain this current in real-world conditions.

Does PHX18NQ20T have a built-in body diode, and what are its key parameters?

Yes, the PHX18NQ20T integrates a source-drain body diode with forward voltage V_SD = 0.9–1.2 V at I_S = 16 A and reverse recovery time t_rr = 130 ns. Its recovered charge Q_r is 0.8 µC, and peak forward current I_SM reaches 33 A in pulsed operation. These values are confirmed in Table 5 (Characteristics) and support efficient freewheeling in hard-switched topologies.

Can PHX18NQ20T be used with gate drive voltages below 10 V, and what is its guaranteed turn-on threshold?

Yes-PHX18NQ20T has a gate-source threshold voltage V_GS(th) of 2–4 V at T_j = 25 °C and remains functional down to 1.2 V at 150 °C (Table 5). It achieves full enhancement at V_GS = 10 V, but will conduct meaningfully at ≥4.5 V. For robust operation, gate drive should exceed 5 V minimum to ensure low R_DS(on) across temperature and process variation.

What is the thermal resistance from junction to heatsink (R_th(j-hs)) for PHX18NQ20T, and how does it impact heatsink sizing?

The PHX18NQ20T has R_th(j-hs) = 4.17 K/W (Table 4), measured with the isolated tab directly mounted to a heatsink. This low value-enabled by the metal tab's direct thermal path-means a 30 W dissipation (P_tot) at 25 °C ambient yields only ~125 °C junction rise, well within the 150 °C limit. Heatsink selection must account for interface resistance and ambient rise, but no insulator is needed.

Is PHX18NQ20T RoHS compliant and lead-free?

The PHX18NQ20T was originally released in 2000, predating RoHS legislation (2006). While NXP's later revisions of compatible devices (e.g., PHX18NQ20T/118) are RoHS-compliant and lead-free, the base PHX18NQ20T part number as documented in Rev. 01 (2000) does not carry RoHS certification. Customers requiring compliance must verify the specific date code and consult NXP's current product change notices for qualified variants.