Nexperia USA Inc. PMST6428,135

Overview

PMST6428 from Nexperia is an NPN general-purpose bipolar junction transistor in SC-70 (SOT323) package, rated for 50 V V_CEO, 100 mA I_C, and 200 mW P_tot, with DC current gain h_FE ≥250 at I_C = 1 mA and f_T up to 700 MHz - used for low-power switching and small-signal amplification in telephony interface circuits.

For engineers reviewing the PMST6428 datasheet, PMST6428 pinout, PMST6428 application, or PMST6428 equivalent, key selection criteria include V_CEO/I_C rating match, h_FE consistency across operating current, V_CEsat at target drive level, thermal resistance on FR4, and SOT323 footprint compatibility in space-constrained PCB layouts.

Technical Context

This device operates as a single NPN silicon BJT optimized for linear amplification and digital switching below 100 mA. Its f_T of 100–700 MHz supports RF front-end biasing and broadband audio preamplifier stages, while its low V_CEsat (≤600 mV at I_C = 100 mA) enables efficient saturation in logic-level interface drivers.

The transistor exhibits tight h_FE distribution across I_C = 0.01–10 mA at V_CE = 5 V, with no degradation below 250 - confirming stable gain behavior in both active and quasi-saturated regions. C_c = 3 pF and C_e = 12 pF support predictable high-frequency impedance matching without external neutralization.

Key Specifications

Pinout & Package

SC-70 (SOT323) plastic surface-mount package: 1.35 mm × 1.15 mm × 0.95 mm body, 0.65 mm lead pitch, 3-terminal configuration with gull-wing leads. Designed for reflow soldering on standard FR4 PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN general-purpose transistor applications.

Compared with BC846B and MMBT3904LT1G, PMST6428 offers superior h_FE stability at low currents and optimal V_CEO/I_C balance for 3.3–12 V systems with strict size constraints - making it preferred for telephony and compact sensor nodes where gain predictability and SOT323 fit are critical.

Availability

PMST6428 is available at Aetrix Electronics and suitable for telephony interface modules, USB power management circuits, industrial sensor signal chains, and portable audio preamplifiers requiring stable component supply across multi-year production cycles.

Supply support for PMST6428 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 leader in discrete, logic, and PowerMOS semiconductors, formed in 2017 from the former NXP Standard Products division, with focus on automotive, industrial, computing, and consumer markets.

PMST6428 belongs to Nexperia's general-purpose bipolar transistor product line, designed specifically for cost-sensitive, space-constrained applications demanding reliable low-current switching and amplification performance.

FAQ

Is PMST6428 RoHS compliant and halogen-free?

Yes, PMST6428 meets RoHS Directive 2011/65/EU and is halogen-free per Nexperia standard specifications. The device carries the "HF" marking on reel labels and conforms to JEDEC J-STD-709A for halogen content limits (Cl ≤ 900 ppm, Br ≤ 900 ppm, total halogens ≤ 1500 ppm).

What is the maximum allowable PCB temperature during reflow soldering?

The PMST6428 SOT323 package is qualified for lead-free reflow per JEDEC J-STD-020 Rev E, with peak temperature of 260 °C for ≤30 seconds. Preheat ramp rate must not exceed 3 °C/s, and time above 217 °C must be 60–150 seconds to ensure intermetallic formation without die attach degradation.

Can PMST6428 replace BC847 in existing designs?

PMST6428 can substitute BC847 in most SOT323-based designs, but note that BC847 has V_CEO = 45 V vs. PMST6428's 50 V, and h_FE min is 110 vs. 250. Gain-critical circuits may require base resistor recalibration; verify V_CEsat and f_T margins at actual operating I_C before drop-in replacement.

Does PMST6428 support automotive AEC-Q101 qualification?

No, PMST6428 is not AEC-Q101 qualified. It is rated for industrial temperature range (−65 °C to +150 °C), but lacks the stress testing, failure analysis, and traceability documentation required for automotive-grade deployment. For AEC-Q101 applications, consider Nexperia's PBSS4041T or PUMD12 series.