Nexperia USA Inc. PMST5551,115

Overview

PMST5551 from Nexperia is an AEC-Q101-qualified NPN high-voltage transistor in SOT323 (SC-70) package, rated for 160 V V_CEO, 300 mA I_C, and 200 mW P_tot. It delivers DC current gain (h_FE) of 30–250 at 50 mA/5 V and supports switching/amplification in telephony and automotive signal conditioning circuits.

For engineers reviewing the PMST5551 datasheet, PMST5551 pinout, PMST5551 application, or PMST5551 equivalent, key selection criteria include its 160 V collector-emitter breakdown voltage, AEC-Q101 qualification for automotive use, SC-70 thermal resistance of 625 K/W, and verified h_FE performance across 1–50 mA operating range.

Technical Context

This discrete NPN bipolar junction transistor operates with open-base V_CEO = 160 V and open-emitter V_CBO = 180 V, enabling robust high-voltage switching in line-powered telecom interfaces. Its pulsed h_FE test conditions (t_p ≤ 300 µs, δ ≤ 0.02) ensure stable gain under transient loads.

Thermal design relies on FR4 PCB mounting with single-sided copper, yielding R_th(j-a) = 625 K/W; saturation voltages are specified at two bias points - V_CE(sat) ≤ 200 mV at I_C = 50 mA/I_B = 5 mA and ≤ 150 mV at I_C = 10 mA/I_B = 1 mA - supporting low-loss switching operation.

Key Specifications

Pinout & Package

Package: SOT323 (SC-70), plastic surface-mounted, 3-lead, 2.0 mm × 1.25 mm × 0.95 mm body, 1.3 mm lead pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC847BW and MMBT5551, PMST5551 uniquely combines 160 V breakdown capability with AEC-Q101 qualification in SC-70 - making it the only option for automotive or telecom systems requiring both high-voltage tolerance and certified reliability.

Availability

PMST5551 is available at Aetrix Electronics and suitable for telephone line interface circuits, automotive door modules, and industrial power supply feedback loops requiring stable component supply and automotive-grade qualification.

Supply support for PMST5551 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

Nexperia is a global semiconductor expert focused on high-volume, high-reliability discrete and logic devices, with manufacturing rooted in process technology leadership and automotive qualification rigor.

PMST5551 belongs to Nexperia's AEC-Q101-qualified high-voltage bipolar transistor family, engineered specifically for automotive signal conditioning and telecom infrastructure where voltage resilience and long-term stability are critical.

FAQ

Is PMST5551 pin-compatible with MMBT5551?

Yes, PMST5551 uses identical SOT323 pinout (1=Base, 2=Emitter, 3=Collector) and mechanical dimensions as MMBT5551. Electrical specifications match exactly, except PMST5551 adds AEC-Q101 qualification and tighter process controls for automotive use cases.

What is the maximum allowable PCB temperature rise during continuous 300 mA operation?

At 300 mA and V_CE = 1 V, power dissipation reaches 300 mW - exceeding the 200 mW P_tot rating. Derating is required: maximum continuous I_C at 25 °C ambient is 300 mA only if V_CE ≤ 0.67 V; otherwise, thermal limits constrain operation to lower current or reduced ambient temperature.

Can PMST5551 replace PN2222A in existing designs?

No - PN2222A uses TO-92 package and has V_CEO = 40 V, making it incompatible with PMST5551's 160 V rating and SC-70 footprint. Direct replacement would require PCB layout change and revalidation of voltage margins, especially in telephony or automotive applications.

Does PMST5551 support pulsed operation beyond 300 mA?

Yes - I_CM (peak collector current) is rated at 600 mA under pulsed conditions (duty cycle ≤ 2%, pulse width ≤ 300 µs). This enables short-duration surge handling in relay driving or fault-detection circuits without thermal damage.