onsemi NSCT3906LT1G

Overview

NSCT3906LT1G from onsemi is a PNP silicon general-purpose transistor in SOT-23 package, rated for −40 V V_CEO, −200 mA I_C, and 225 mW power dissipation on FR-5 board. It delivers DC current gain (h_FE) of 60–300 across 0.1–100 mA I_C, with V_CE(sat) ≤ −0.25 V at −10 mA/−1 mA drive, used in discrete logic-level switching and signal inversion circuits.

For engineers reviewing the NSCT3906LT1G datasheet, pinout, applications, or equivalent options, key selection criteria include verified PNP polarity, SOT-23 footprint compatibility, guaranteed −40 V breakdown, low saturation voltage under defined bias conditions, and Pb-free compliance per J-STD-609.

Technical Context

This device operates as a discrete bipolar junction transistor with fixed PNP polarity and no integrated biasing or protection. Its small-signal current gain (h_fe) ranges 100–400 at 1 kHz, and f_T is 250 MHz at −10 mA/−20 V, supporting audio-frequency amplification and fast-switching applications up to ~100 MHz.

Thermal performance is defined for two board types: R_JA = 556 °C/W on FR-5 (225 mW @ 25°C) and 417 °C/W on alumina (300 mW @ 25°C). Junction temperature must remain within −55°C to +150°C for reliable operation.

Key Specifications

Pinout & Package

SOT-23 (TO-236) package, 3-pin surface-mount, case 318-08, 1.0 mm × 1.4 mm × 0.95 mm body height, 0.65 mm pitch. RoHS-compliant matte tin finish, tape-and-reel packaging (3,000 units/reel).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBT3906LT1G, NSCT3906LT1G offers identical performance in the same SOT-23 footprint but with distinct reel packaging and date-code marking; versus PN2907A, it provides superior thermal efficiency and RF capability in a compact surface-mount form factor.

Availability

NSCT3906LT1G is available at Aetrix Electronics and suitable for LED driver switching, level-shifting interfaces, audio pre-amplifier stages, power supply enable control, and discrete logic inversion requiring stable component supply and Pb-free compliance.

Supply support for NSCT3906LT1G 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

onsemi (Nasdaq: ON) is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The NSCT3906LT1G belongs to onsemi's general-purpose bipolar transistor product line, designed for cost-sensitive, high-volume discrete switching and amplification in consumer, computing, and industrial electronics where reliability and Pb-free compliance are essential.

FAQ

What is the maximum continuous collector current rating for NSCT3906LT1G?

The NSCT3906LT1G has a maximum continuous collector current (I_C) rating of −200 mA at T_A = 25°C. This rating applies to DC or low-duty-cycle pulsed operation on FR-5 board; derating is required above 25°C at 1.8 mW/°C. The device maintains specified h_FE and V_CE(sat) performance up to −100 mA under typical bias conditions.

Is NSCT3906LT1G pin-compatible with MMBT3906LT1G?

Yes, NSCT3906LT1G is pin-compatible with MMBT3906LT1G: both use identical SOT-23 package with Base–Emitter–Collector pinout (1–2–3), same thermal and electrical specifications, and share the same onsemi die. The difference lies only in part marking, tape-and-reel packaging quantity (3,000 vs. 10,000), and internal order code - no PCB or schematic changes are needed.

What is the typical noise figure of NSCT3906LT1G and under what conditions is it measured?

The NSCT3906LT1G has a typical noise figure (NF) of 4.0 dB, measured at I_C = −100 µA, V_CE = −5.0 V, R_S = 1.0 kΩ, and f = 1.0 kHz. This value is confirmed in the official onsemi datasheet Figure 7 and reflects performance in low-current audio pre-amplifier applications where signal integrity at sub-mV levels is critical.

Does NSCT3906LT1G support high-speed switching applications?

Yes, NSCT3906LT1G supports high-speed switching with documented t_d ≤ 35 ns, t_r ≤ 35 ns, t_s ≤ 225 ns, and t_f ≤ 75 ns under V_CC = −3.0 V, I_C = −10 mA, and I_B1 = −1.0 mA test conditions. Its 250 MHz f_T further validates suitability for digital signal routing and clock buffering up to ~50 MHz.

What is the thermal resistance junction-to-ambient for NSCT3906LT1G on standard FR-5 PCB?

The thermal resistance junction-to-ambient (R_JA) for NSCT3906LT1G on FR-5 board is 556 °C/W at T_A = 25°C, corresponding to a total device dissipation (P_D) of 225 mW. Derating is linear at 1.8 mW/°C above 25°C, meaning usable power drops to ~135 mW at 85°C ambient - critical for thermal design in enclosed industrial enclosures.