onsemi NST848BF3T5G

Overview

NST848BF3T5G from onsemi is an NPN general-purpose bipolar junction transistor in SOT-1123 package, rated for V_CEO = 30 V, I_C = 100 mA, and h_FE = 200–450. It delivers low V_CE(sat) ≤ 0.25 V at I_C = 10 mA / I_B = 0.5 mA and supports f_T = 100 MHz, making it suitable for compact low-power amplifier and switching circuits in space-constrained PCBs.

For engineers reviewing the NST848BF3T5G datasheet, pinout, applications, or equivalent options, key selection criteria include its SOT-1123 footprint, guaranteed h_FE range, thermal resistance (R_JA = 360 °C/W with 500 mm² copper), Pb-free/Halide-free compliance, and verified performance at −55°C to +150°C junction temperature.

Technical Context

This NPN BJT operates in linear amplification and saturated switching modes, with base-emitter turn-on voltage V_BE(on) = 580–770 mV and saturation voltage V_CE(sat) as low as 0.25 V. Its f_T = 100 MHz enables RF-capable small-signal amplification up to VHF bands.

Thermal design leverages two dissipation ratings: 290 mW (100 mm² copper) and 347 mW (500 mm² copper), with corresponding R_JA values of 432 °C/W and 360 °C/W. The device's C_ibo = 10 pF and C_obo = 4.5 pF support stable high-frequency biasing and low-noise operation (NF = 10 dB at 1 kHz).

Key Specifications

Pinout & Package

Package: SOT-1123 (Case 524AA), ultra-compact 3-pin surface-mount plastic package with 0.35 mm pitch, optimized for high-density layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBT3904LT1G and PN2222A-AP, the NST848BF3T5G provides superior high-frequency capability (f_T = 100 MHz), tighter h_FE distribution, and a 40% smaller footprint-making it optimal for miniaturized, high-reliability, and RoHS-compliant designs where thermal efficiency and signal integrity matter.

Availability

NST848BF3T5G is available at Aetrix Electronics and suitable for portable audio amplifiers, load switch control, RF front-end biasing, and industrial sensor signal conditioning requiring stable component supply, RoHS compliance, and long-term manufacturability.

Supply support for NST848BF3T5G 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 (formerly ON Semiconductor) is a global semiconductor supplier focused on energy-efficient innovation for automotive, industrial, cloud, and IoT applications.

The NST848BF3T5G belongs to onsemi's general-purpose bipolar transistor family designed specifically for space-constrained, low-power linear and switching functions in consumer and industrial edge devices.

FAQ

What is the maximum junction temperature rating for the NST848BF3T5G?

The NST848BF3T5G has a specified junction and storage temperature range of −55°C to +150°C. This wide rating allows operation in harsh environments such as automotive engine compartments or industrial motor controls. Derating curves in the datasheet confirm safe operation up to 150°C with appropriate PCB copper area (500 mm²), and the device maintains h_FE and V_CE(sat) stability across this full range. The NST848BF3T5G is qualified per AEC-Q101 for stress-tested reliability.

Does the NST848BF3T5G support high-frequency amplification?

Yes, the NST848BF3T5G features a current-gain–bandwidth product (f_T) of 100 MHz at I_C = 10 mA and V_CE = 5.0 V, enabling use in VHF amplifiers, RF bias networks, and local oscillator driver stages. Its low C_ibo (10 pF) and C_obo (4.5 pF) minimize unwanted coupling, and measured noise figure is 10 dB at 1 kHz-supporting clean signal amplification. The NST848BF3T5G is not intended for microwave frequencies (>1 GHz) but performs reliably up to ~200 MHz in well-designed matching networks.

Is the NST848BF3T5G pin-compatible with standard SOT-23 transistors?

No, the NST848BF3T5G uses the SOT-1123 package (0.35 mm pitch), which is physically smaller and not pin-compatible with SOT-23 (0.95 mm pitch) or SOT-323. Pin 1 is Base, Pin 2 is Emitter, Pin 3 is Collector-same signal assignment as many SOT-23 NPNs, but mechanical incompatibility prevents direct replacement without PCB redesign. The NST848BF3T5G requires dedicated SOT-1123 land patterns per onsemi's mechanical drawing 98AON23134D.

What does the "F3" suffix indicate in NST848BF3T5G?

The "F3" in NST848BF3T5G denotes a specific die variant within onsemi's NST848B series, characterized by guaranteed h_FE = 200–450 and optimized V_CE(sat) performance. It distinguishes this version from earlier revisions (e.g., F2) with different gain bins or thermal specs. The "T5G" suffix confirms tape-and-reel packaging (8000 units/reel) and Pb-free (RoHS-compliant) construction. The NST848BF3T5G is fully traceable to onsemi's Rev. 2 datasheet (May 2024).

How does thermal performance differ between 100 mm² and 500 mm² copper layouts for the NST848BF3T5G?

The NST848BF3T5G specifies two thermal derating profiles: with 100 mm² copper, PD = 290 mW and R_JA = 432 °C/W; with 500 mm² copper, PD = 347 mW and R_JA = 360 °C/W. This 17% increase in power handling enables higher continuous current in thermally demanding applications like always-on sensor nodes. Layouts using internal layers or thermal vias can further improve R_JA, but the NST848BF3T5G's datasheet validates only these two standardized test conditions.