onsemi MPS6518

Overview

MPS6518 from Fairchild Semiconductor is a PNP general-purpose bipolar junction transistor designed for low-power amplification and switching applications, with a 40 V V_CEO, 200 mA continuous collector current rating, and DC current gain (h_FE) of 150–300 at 2 mA, used in signal conditioning stages of consumer audio preamps and discrete logic inverters.

For engineers reviewing the MPS6518 datasheet, pinout, applications, or equivalent options, key selection criteria include its TO-92 package compatibility, verified V_CE(sat) ≤ 0.5 V at I_C = 50 mA/I_B = 5 mA, thermal resistance R_θJA = 200 °C/W, and suitability for linear amplification or saturated-switching roles in cost-sensitive analog subsystems.

Technical Context

The MPS6518 operates as a silicon PNP BJT with fixed-emitter bias topology, supporting both active-mode amplification (V_CE ≥ 1 V) and saturation-mode switching (V_CE(sat) ≤ 0.5 V). Its h_FE variation across I_C = 2–100 mA confirms stable gain behavior in mid-current range.

Thermal design relies on its 625 mW total dissipation at 25°C, derated by 5.0 mW/°C above ambient, and junction-to-ambient thermal resistance of 200 °C/W - consistent with standard TO-92 plastic package limitations and requiring no heatsink below 100 mW power dissipation.

Key Specifications

Pinout & Package

Package: TO-92 - standard 3-lead through-hole plastic package with flat side identifying emitter-collector orientation; lead spacing 0.500", height 0.928", weight 0.1977 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 2N3906 and MPSA92, the MPS6518 delivers higher guaranteed h_FE and lower V_CE(sat), making it preferable for gain-critical amplifiers and low-loss switches in 5–24 V systems - while maintaining full TO-92 footprint compatibility and identical pinout.

Availability

MPS6518 is available at Aetrix Electronics and suitable for audio pre-amplifier stages, discrete logic inverters, LED driver circuits, and temperature sensor interfaces requiring stable component supply and long-term manufacturing continuity.

Supply support for MPS6518 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

Fairchild Semiconductor was a U.S.-based semiconductor manufacturer specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016.

The MPS6518 belongs to Fairchild's legacy general-purpose transistor family, engineered for cost-effective, reliable amplification and switching in consumer, industrial, and automotive auxiliary electronics.

FAQ

What is the maximum collector current rating for the MPS6518?

The MPS6518 has an absolute maximum continuous collector current (I_C) of 200 mA at T_A = 25°C. However, the device is functionally specified for use up to 100 mA per its design documentation, ensuring stable h_FE and thermal performance without forced cooling. Derating is required above 25°C at 5.0 mW/°C.

Does the MPS6518 have the same pinout as the 2N3906?

Yes, the MPS6518 uses the standard TO-92 package with identical pinout to the 2N3906: Emitter (lead 1), Base (lead 2), Collector (lead 3) when viewed with flat side facing outward and leads down. This allows direct substitution in existing layouts where thermal and gain margins permit.

What is the typical DC current gain (h_FE) of the MPS6518 at 10 mA collector current?

At V_CE = 10 V and I_C = 10 mA, the MPS6518 exhibits h_FE between 150 and 300 per its datasheet. The typical value falls near 225, supporting robust base drive design for both linear and switching applications without requiring tight binning.

Can the MPS6518 be used in high-frequency amplifier circuits?

The MPS6518 has an output capacitance (C_ob) of 4.0 pF at V_CB = 10 V, limiting its useful small-signal bandwidth to approximately 10 MHz. It is not recommended for RF or broadband applications but performs reliably in audio and low-speed digital signal conditioning where stability and gain consistency are prioritized.

What is the junction-to-ambient thermal resistance (R_θJA) of the MPS6518?

The MPS6518 has a specified R_θJA of 200 °C/W in free-air conditions using the standard TO-92 package. This means a 100 mW power dissipation will raise the junction temperature by 20°C above ambient - confirming suitability for unheatsinked operation in most low-power analog and logic interface designs.