onsemi MPS918G

Overview

MPS918G 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 MPS918G datasheet, pinout, applications, or equivalent options, key selection criteria include its 15 V collector-emitter breakdown voltage, 600 MHz transition frequency, Pb-free TO-92 packaging, 0.4 V saturation voltage at 10 mA drive, and suitability for Class-C RF amplification up to 500 MHz.

Technical Context

The MPS918G operates as a general-purpose NPN bipolar junction transistor optimized for RF small-signal amplification and oscillator circuits. Its design supports stable gain at frequencies up to 500 MHz, with verified P_out = 30 mW and η = 25% oscillator collector efficiency under specified bias conditions (I_C = 8.0 mA, V_CB = 15 V).

It features low noise figure (NF ≤ 6.0 dB at 60 MHz), moderate input capacitance (C_ibo ≤ 2.0 pF), and tight thermal resistance (R_JC = 147 °C/W), enabling reliable operation in compact, thermally constrained PCB layouts without forced cooling.

Key Specifications

Pinout & Package

Package: TO-92 (Case 29-11, Style 17), Pb-free, through-hole mounting. Dimensions per onsemi mechanical drawing 98ASB42022B.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPS3563G and BC547C, the MPS918G offers balanced RF capability (600 MHz f_T) and voltage robustness (15 V V_CEO) in a Pb-free TO-92 package - making it optimal for cost-sensitive, medium-frequency oscillator and driver designs where both gain bandwidth and supply margin matter.

Availability

MPS918G is available at Aetrix Electronics and suitable for FM transmitter oscillators, portable audio preamplifiers, and ISM-band sensor node transmitters requiring stable component supply and RoHS-compliant through-hole assembly.

Supply support for MPS918G 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, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The MPS918G belongs to onsemi's Preferred Devices family of general-purpose bipolar transistors, designed for cost-effective, high-reliability RF and audio signal amplification in volume production.

FAQ

What is the maximum operating frequency for the MPS918G in amplifier configurations?

The MPS918G has a transition frequency f_T of 600 MHz, verified under I_C = 4.0 mA, V_CE = 10 V, and f = 100 MHz test conditions. In practical common-emitter amplifier designs, usable small-signal gain extends reliably to 200–300 MHz; at 500 MHz, the MPS918G delivers 30 mW output power in oscillator mode with 25% collector efficiency, confirming functional RF capability beyond 400 MHz.

Is the MPS918G pin-compatible with the MPS3563G?

No - while both the MPS918G and MPS3563G use TO-92 packages and share identical pinout (Emitter/Base/Collector on pins 1/2/3 per Style 17), they are not functionally interchangeable without circuit review. The MPS3563G has lower V_CEO (12 V vs. 15 V) and higher f_T (1500 MHz vs. 600 MHz), requiring bias and matching network adjustments. The MPS918G datasheet does not claim pin compatibility or drop-in replacement status with MPS3563G.

What is the thermal resistance junction-to-case (R_JC) for the MPS918G?

The MPS918G has a thermal resistance R_JC of 147 °C/W, measured under standard test conditions per onsemi specification. This value applies when the device is mounted with proper lead soldering to a PCB and reflects heat transfer from die to case surface - critical for estimating junction temperature rise during continuous 350 mW dissipation in confined enclosures.

Does the MPS918G support Pb-free reflow soldering?

Yes - the MPS918G is explicitly marked as Pb-free in the ordering information and conforms to onsemi's Pb-free strategy. It supports standard SnPb and lead-free reflow profiles per the onsemi Soldering and Mounting Techniques Reference Manual (SOLDERRM/D), with peak temperatures up to 260 °C for 10 seconds, validated for TO-92 package integrity and wire bond reliability.

What is the typical noise figure of the MPS918G and under what conditions is it measured?

The MPS918G has a maximum noise figure (NF) of 6.0 dB, measured at I_C = 1.0 mA, V_CE = 6.0 V, source impedance R_S = 400 kΩ, and frequency f = 60 MHz. This value reflects small-signal noise performance in common-emitter configuration and is representative for low-noise preamplifier use in audio and narrowband RF applications below 100 MHz.