onsemi MPS918

Overview

MPS918 from onsemi is an NPN silicon small-signal amplifier transistor in TO-92 package, rated for V_CEO = 15 V, I_C = 50 mA, and f_T = 600 MHz, with h_FE ≥ 20 at I_C = 3.0 mA and V_CE = 1.0 V - used in RF oscillator and broadband amplifier stages in consumer audio and low-power wireless transmitters.

For engineers reviewing the MPS918 datasheet, pinout, applications, or equivalent options, key selection criteria include its 15 V collector-emitter breakdown rating, 600 MHz gain-bandwidth product, low 0.4 V saturation voltage, Pb-free TO-92 packaging, and suitability for Class-A RF amplification up to 500 MHz.

Technical Context

The MPS918 operates as a general-purpose NPN bipolar junction transistor optimized for RF small-signal amplification and oscillator circuits. Its design supports DC-coupled common-emitter configurations with V_CE(sat) ≤ 0.4 V at I_C = 10 mA / I_B = 1.0 mA and V_BE(sat) ≤ 1.0 V under same conditions.

Thermal performance is defined by R_JA = 357 °C/W (PCB-mounted) and R_JC = 147 °C/W, enabling operation from −55 °C to +150 °C junction temperature. Electrical characterization includes noise figure NF ≤ 6.0 dB at 60 MHz, C_ibo = 2.0 pF, and C_obo = 3.0 pF at specified bias conditions.

Key Specifications

Pinout & Package

Package: TO-92 (Case 29-11, Style 17), through-hole plastic package with standardized lead pitch and mechanical outline per ON Semiconductor specification.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN small-signal amplifier applications.

Compared with MPS3563 and 2N3904, the MPS918 offers optimal balance of 15 V voltage rating, 600 MHz bandwidth, and low-noise RF performance - making it preferred for cost-sensitive UHF oscillator and medium-bandwidth amplifier designs where V_CEO margin and thermal resistance (R_JA = 357 °C/W) are critical.

Availability

MPS918 is available at Aetrix Electronics and suitable for FM transmitter modules, audio preamplifiers, RF detector bias networks, and LED driver switches requiring stable component supply and RoHS-compliant through-hole packaging.

Supply support for MPS918 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 specializing in energy-efficient power management, analog, sensors, and connectivity solutions for automotive, industrial, and consumer markets.

The MPS918 belongs to onsemi's legacy amplifier transistor family designed for reliable, low-cost RF and audio signal amplification in space-constrained, thermally sensitive applications.

FAQ

What is the maximum operating junction temperature for the MPS918?

The MPS918 has an operating and storage junction temperature range of −55 °C to +150 °C. This wide range allows deployment in automotive under-hood environments and industrial equipment with elevated ambient temperatures. The device's thermal resistance R_JC = 147 °C/W enables effective heat transfer to heatsinks or PCB copper when mounted in high-reliability applications. Always verify actual junction temperature using T_J = T_A + (P_D × R_JA) in final layout.

Is the MPS918 pin-compatible with the 2N3904?

No, the MPS918 is not pin-compatible with the 2N3904. While both use TO-92 packages, the MPS918 follows Style 17 pinout (Emitter-Base-Collector), whereas the 2N3904 uses Style 2 (Base-Emitter-Collector). Swapping them without board revision will reverse emitter and base connections, causing circuit failure. Always confirm pinout diagrams from official onsemi documentation before substitution.

Does the MPS918 support Pb-free soldering processes?

Yes, the MPS918G variant is explicitly designated as Pb-free and qualified for standard reflow and wave soldering per J-STD-020 and J-STD-006. The standard MPS918 is also compatible with Pb-free processes, as confirmed in ON Semiconductor's Soldering and Mounting Techniques Reference Manual (SOLDERRM/D). Both variants meet RoHS Directive 2011/65/EU requirements without derating.

What is the typical noise figure of the MPS918 and at what conditions is it measured?

The MPS918 has a maximum noise figure (NF) of 6.0 dB, measured at I_C = 1.0 mA, V_CE = 6.0 V, R_S = 400 Ω, and f = 60 MHz. This value reflects its suitability for low-noise RF amplification in IF stages and receiver front-ends. Actual NF varies with bias point and source impedance; designers should optimize base bias and emitter degeneration to achieve best noise performance in target frequency bands.

Can the MPS918 be used in switching applications?

Yes, the MPS918 can be used in low-speed switching applications such as LED drivers or relay controls, thanks to its V_CE(sat) ≤ 0.4 V at I_C = 10 mA and I_B = 1.0 mA. However, it is not optimized for high-frequency switching - its f_T = 600 MHz reflects small-signal AC performance, not switching speed. For fast digital switching (>1 MHz), dedicated switching transistors like MMBT2222A are recommended instead of the MPS918.