Nexperia USA Inc. PMST3904,135

Overview

PMST3904 from Nexperia is an AEC-Q101-qualified NPN bipolar junction transistor in SOT323 (SC-70) package, rated for 40 V V_CEO, 200 mA I_C, and DC current gain (h_FE) of 100–300 at I_C = 10 mA, used for low-power switching and amplification in space-constrained automotive and industrial control circuits.

For engineers reviewing the PMST3904 datasheet, PMST3904 pinout, PMST3904 application, or PMST3904 equivalent, key selection criteria include its SC-70 footprint compatibility, 200 mW power dissipation at T_amb ≤ 25 °C, 35 ns rise/fall times, and AEC-Q101 qualification status - critical for reliability-critical signal routing and load switching.

Technical Context

This discrete NPN transistor operates as a saturated switch or linear amplifier with V_CE(sat) ≤ 850 mV at I_C = 10 mA / I_B = 1 mA and V_BE(sat) ≤ 950 mV under same conditions. Its f_T of 300 MHz supports high-speed digital switching up to ~10 MHz edge rates.

Thermal resistance R_th(j-a) is 625 K/W on FR4 PCB (single-sided copper), limiting continuous I_C to ~120 mA at T_j = 150 °C ambient. Switching performance is characterized using standardized test circuit per Fig. 6 with defined pulse conditions (t_p ≤ 300 µs, δ ≤ 0.02).

Key Specifications

Pinout & Package

SOT323 (SC-70) plastic surface-mount package: 3-pin, 1.3 mm pitch, 2.0 mm × 1.25 mm × 0.95 mm body, optimized for high-density PCB layouts and reflow soldering.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN switching transistor applications.

Compared with BC846B,215 and MMBT3904LT1G, PMST3904 uniquely combines AEC-Q101 qualification, SOT323 size, and 40 V/200 mA ratings - making it optimal for new automotive and space-limited industrial designs where qualification and miniaturization are jointly critical.

Availability

PMST3904 is available at Aetrix Electronics and suitable for automotive door modules, industrial sensor interfaces, consumer power management, and medical diagnostic equipment requiring stable component supply and AEC-Q101-compliant discrete transistors.

Supply support for PMST3904 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 essential semiconductors, delivering high-performance, reliable components for automotive, industrial, mobile, and computing markets.

PMST3904 belongs to Nexperia's AEC-Q101-qualified general-purpose transistor product line, engineered for robust low-voltage switching and amplification in thermally demanding, space-constrained applications.

FAQ

Is PMST3904 suitable for automotive applications?

Yes - PMST3904 is explicitly AEC-Q101 qualified per its 2025 data sheet, with validated HTOL, temperature cycling, and HAST testing. It is approved for non-safety-critical automotive use such as body electronics and infotainment peripherals, though not for airbag or braking systems.

What is the maximum allowable continuous collector current at 85 °C ambient?

At T_amb = 85 °C, derating begins at 200 mA maximum. Using R_th(j-a) = 625 K/W and T_j(max) = 150 °C, the allowable I_C drops to approximately 105 mA to maintain T_j ≤ 150 °C with P_tot = I_C × V_CE(sat) ≈ 90 mW.

Can PMST3904 replace MMBT3904 in existing SOT-23 designs?

No - PMST3904 uses SOT323 (SC-70), which has different pad layout, dimensions (2.0 × 1.25 mm vs. 2.9 × 1.3 mm), and thermal profile than SOT-23. Direct replacement requires PCB redesign; however, electrical behavior is functionally equivalent when properly re-biased.

Does PMST3904 have built-in ESD protection?

No - PMST3904 lacks integrated ESD protection diodes. Its CDM and HBM ESD ratings are not specified in the data sheet; external series resistors (≥1 kΩ) and PCB layout best practices (short traces, ground shielding) are recommended for handling-sensitive applications.