Nexperia USA Inc. PMST3904,115

Overview

PMST3904 from Nexperia is an AEC-Q101-qualified NPN switching transistor in SOT323 (SC-70) package, rated for V_CEO = 40 V, I_C = 200 mA, and h_FE = 100–300 at I_C = 10 mA. It delivers low V_CE(sat) (650–850 mV at I_C/I_B = 10) and fast switching (t_d/t_r ≤ 35 ns), used in compact load switching and signal amplification circuits on space-constrained PCBs.

For engineers reviewing the PMST3904 datasheet, PMST3904 pinout, PMST3904 application, or PMST3904 equivalent, key selection criteria include its SC-70 footprint compatibility, guaranteed h_FE range across temperature, AEC-Q101 qualification status (per revision v.3), V_CE(sat) performance at 10 mA drive, and thermal resistance (R_th(j-a) = 625 K/W on FR4).

Technical Context

This discrete NPN bipolar junction transistor operates in active or saturation mode for digital switching and linear amplification. Its design centers on high-current gain consistency (h_FE ≥ 100 at I_C = 10 mA, T_amb = 25 °C) and robust thermal behavior under pulsed conditions (t_p ≤ 300 µs, duty δ ≤ 0.02).

It features low leakage (I_CBO, I_EBO ≤ 50 nA), tight V_BE(sat) control (≤ 950 mV at I_C = 50 mA), and defined switching dynamics (t_s ≤ 200 ns, t_f ≤ 50 ns) with specified test circuit per Figure 6 - enabling predictable timing in gate-drive and logic-level interface stages.

Key Specifications

Pinout & Package

SOT323 (SC-70) plastic surface-mounted package: 3-pin, 1.3 mm pitch, 2.0 mm × 1.25 mm × 0.95 mm body; optimized for reflow soldering with standardized footprint (Figure 8).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC846B,115, PMST3904 trades higher V_CEO for automotive qualification; compared with MMBT3904LT1G, it sacrifices thermal performance for 35% smaller footprint - making it optimal for ultra-compact, non-automotive consumer or computing applications.

Availability

PMST3904 is available at Aetrix Electronics and suitable for LED driver circuits, microcontroller GPIO expansion, low-voltage relay drivers, and signal-level amplifier stages requiring stable component supply and consistent parametric performance across production lots.

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 high-volume, high-reliability discrete and logic devices, with leadership in ESD protection, MOSFETs, and bipolar transistors.

The PMST3904 belongs to Nexperia's general-purpose bipolar transistor product line, engineered for space-constrained switching and amplification in consumer, computing, and industrial equipment - prioritizing footprint efficiency and parametric consistency over automotive qualification in latest revisions.

FAQ

Is PMST3904 qualified for automotive applications?

No - per datasheet revision v.4 (Sept 2025), PMST3904 is explicitly marked "non-automotive qualified" and superseded for automotive use. The v.3 revision noted AEC-Q101 qualification, but this was removed due to product reclassification. For automotive designs, consult Nexperia's PMST3904-Q series or equivalent qualified alternatives.

What is the maximum allowable base current for continuous operation?

The absolute maximum peak base current (I_BM) is 100 mA, but continuous DC base current must be limited by thermal constraints. At T_amb = 25 °C, P_tot = 200 mW limits I_B to ≤ 2 mA when V_BE ≈ 0.7 V; for reliable long-term operation, keep I_B ≤ 1 mA with adequate PCB copper pour.

Can PMST3904 replace BC847 in existing SOT323 designs?

Yes - PMST3904 and BC847 share identical SOT323 pinout, V_CEO = 45 V (BC847) vs. 40 V (PMST3904), and overlapping h_FE ranges. However, verify that 40 V rating suffices for your application's worst-case V_CE stress, and confirm switching speed requirements align - PMST3904 has faster t_f (≤50 ns vs. typical 60 ns).

How does thermal performance change on 2-layer vs. 4-layer PCBs?

The datasheet R_th(j-a) = 625 K/W assumes single-sided FR4 (1 oz Cu). On 2-layer boards with internal ground planes, R_th(j-a) improves to ~450 K/W; on 4-layer boards with thermal vias to inner planes, it reaches ~320 K/W. This directly increases usable I_C - e.g., 200 mA becomes sustainable at T_amb = 85 °C on 4-layer versus 60 °C on single-sided.