NXP Semiconductors PMST5401,115

Overview

PMST5401 from NXP Semiconductors (formerly Philips) is a PNP high-voltage general-purpose transistor in SOT323 package, rated for −150 V V_CEO, −300 mA I_C, and 200 mW P_tot, with h_FE = 60–240 at −10 mA, used in telephony line interface and low-power switching circuits.

For engineers reviewing the PMST5401 datasheet, PMST5401 pinout, PMST5401 application, or PMST5401 equivalent, key selection considerations include its PNP polarity, SOT323 footprint compatibility, −150 V breakdown rating, DC current gain range, and thermal resistance of 625 K/W on FR4 PCB.

Technical Context

The PMST5401 operates as a medium-speed PNP bipolar junction transistor optimized for high-voltage, low-current linear and switching roles. Its f_T of 100–300 MHz supports audio-frequency amplification and pulse applications, while V_BEsat ≤ −1 V at −50 mA ensures predictable base drive requirements.

Designed for operation up to T_j = 150 °C and ambient temperatures from −65 °C to +150 °C, it features low leakage (I_CBO ≤ −50 nA at −120 V), 6 pF collector capacitance, and noise figure ≤ 8 dB in 10 Hz–15.7 kHz band - suitable for telephony signal conditioning.

Key Specifications

Pinout & Package

SOT323 (SC-70) plastic surface-mount package: 3-lead, 1.3 mm × 2.2 mm footprint, 0.65 mm pitch, 0.45 mm max height; compatible with automated pick-and-place and reflow soldering.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP high-voltage transistor applications.

Compared with BC807-40,115, the PMST5401 delivers 3.3× higher voltage blocking essential for telecom infrastructure; versus MMBT5401, it offers identical functionality but differs in manufacturing origin and traceability chain - both remain valid alternatives depending on supply chain and compliance requirements.

Availability

PMST5401 is available at Aetrix Electronics and suitable for telephony line interface, low-power switching regulator, and audio signal amplifier applications requiring stable component supply, long-term obsolescence management, and RoHS-compliant sourcing.

Supply support for PMST5401 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 markets, with roots in Philips' pioneering discrete device development.

The PMST5401 belongs to NXP's legacy high-voltage bipolar transistor family, designed specifically for reliability-critical analog signal paths in telecom and industrial control systems where voltage robustness and thermal stability are paramount.

FAQ

What is the maximum collector-emitter voltage rating for the PMST5401?

The PMST5401 has a maximum collector-emitter voltage (V_CEO) rating of −150 V with open base, verified per IEC 134 Absolute Maximum Ratings. This allows safe operation in −48 V telephony systems with ringing transients, and confirms suitability for high-side PNP switching up to this voltage threshold. The PMST5401 must not be operated beyond this limit to prevent junction breakdown.

Is the PMST5401 pin-compatible with the MMBT5401?

Yes, the PMST5401 is pin-compatible with the MMBT5401: both use identical SOT323 (SC-70) package outlines, share identical pin 1 (base), pin 2 (emitter), pin 3 (collector) assignments, and match electrically across all key parameters including V_CEO, h_FE, and V_CEsat. The PMST5401 and MMBT5401 can be substituted without PCB layout changes in most applications.

What is the typical DC current gain (h_FE) of the PMST5401 at −10 mA collector current?

The PMST5401 exhibits a typical DC current gain (h_FE) of 60–240 at V_CE = −5 V and I_C = −10 mA, as specified in the Philips datasheet. This wide range reflects process variation and supports design margining for base drive calculations. The PMST5401's h_FE remains stable across its operating temperature range, enabling predictable biasing in production units.

Can the PMST5401 be used in audio amplifier applications?

Yes, the PMST5401 is suitable for low-noise audio preamplifier stages due to its ≤ 8 dB noise figure in the 10 Hz–15.7 kHz band, f_T ≥ 100 MHz, and low leakage (I_CBO ≤ −50 nA). Its PNP configuration allows complementary use with NPN devices like PMST5551 in push-pull topologies. The PMST5401 delivers clean gain in Class-A configurations without introducing audible distortion.

What is the thermal resistance (R_{th j-a}) of the PMST5401 on FR4 PCB?

The PMST5401 has a junction-to-ambient thermal resistance (R_{th j-a}) of 625 K/W when mounted on a standard FR4 printed-circuit board, as measured under defined test conditions. This value governs safe power derating: for example, at 70 °C ambient, maximum allowable P_tot drops to ~120 mW. The PMST5401's thermal performance is validated for standard reflow assembly without added copper pour.