onsemi MPS6531

Overview

MPS6531 from Fairchild Semiconductor is an NPN general-purpose bipolar junction transistor designed for medium-power amplification and switching applications, with a continuous collector current rating of 1.0 A, V_CEO = 40 V, and DC current gain (h_FE) ranging from 60 to 270 at IC = 10–500 mA. It is commonly used in low-voltage power supplies, relay drivers, and signal amplification stages where robust thermal performance and reliable saturation behavior are required.

For engineers reviewing the MPS6531 datasheet, pinout, applications, or equivalent options, key selection considerations include its TO-92 package compatibility, verified V_CE(sat) ≤ 0.3 V at I_C = 100 mA / I_B = 10 mA, guaranteed breakdown voltages (V_(BR)CEO ≥ 40 V), and thermal resistance R_θJA = 200 °C/W for board-level thermal design.

Technical Context

The MPS6531 operates as a silicon NPN BJT fabricated using Fairchild's Process 19, optimized for stable DC gain and low saturation voltage across collector currents up to 500 mA. Its junction temperature range spans –55°C to +150°C, supporting operation in industrial ambient environments without derating below 25°C.

Electrical behavior is characterized by tightly specified OFF-state leakage (I_CBO ≤ 50 nA at V_CB = 40 V), predictable ON-state parameters (V_BE(sat) ≤ 1.0 V), and small-signal output capacitance (C_ob = 5.0 pF at V_CB = 10 V), making it suitable for both linear amplification and fast-switching roles in discrete analog and power-control circuits.

Key Specifications

Pinout & Package

Package: TO-92 - Standard 3-lead through-hole plastic package with 0.1" lead pitch, compatible with manual soldering and wave soldering processes. Dimensions conform to JEDEC TO-92 outline (1:1 scale drawing provided in datasheet Rev. B).

Key Features

Applications

Equivalent & Alternatives

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

Compared with PN2222A and BC547B, the MPS6531 uniquely balances 1.0 A current capability, 40 V breakdown, and TO-92 form factor-making it the only option among the three qualified for sustained 500–1000 mA switching without package or thermal compromise.

Availability

MPS6531 is available at Aetrix Electronics and suitable for relay drivers, linear regulator pass elements, audio preamplifiers, and LED current switches requiring stable component supply and long-term industrial availability.

Supply support for MPS6531 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 company specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016. Its legacy products remain widely deployed in industrial and automotive systems.

The MPS6531 belongs to Fairchild's general-purpose NPN transistor family engineered for cost-sensitive, medium-power analog and switching applications where reliability, thermal stability, and consistent gain behavior are critical.

FAQ

What is the maximum continuous collector current rating for the MPS6531?

The MPS6531 has a maximum continuous collector current (I_C) rating of 1.0 A at T_A = 25°C. Derating applies above 25°C per the specified 5.0 mW/°C thermal derating curve. This rating enables use in medium-power switching applications such as relay drivers and LED current switches without auxiliary heatsinking under typical ambient conditions.

Does the MPS6531 have a guaranteed minimum DC current gain (h_FE)?

Yes, the MPS6531 guarantees h_FE ≥ 60 at V_CE = 1.0 V and I_C = 10 mA, and ≥ 50 at V_CE = 10 V and I_C = 500 mA. These values are measured and binned per datasheet test conditions, supporting reliable base drive calculation in both amplification and saturated-switch configurations involving the MPS6531.

What is the collector-emitter saturation voltage (V_CE(sat)) of the MPS6531 under typical switching conditions?

The MPS6531 exhibits V_CE(sat) ≤ 0.3 V when operated at I_C = 100 mA and I_B = 10 mA. This low saturation voltage directly reduces conduction losses and junction heating, making the MPS6531 well-suited for efficient on/off control of moderate-current loads in applications such as power supply enable circuits and sensor interface switches.

Is the MPS6531 available in tape-and-reel packaging?

Yes, the MPS6531 is offered in tape-and-reel packaging with 2,000 units per reel (EOL codes D26Z, D27Z, D74Z, D75Z). Reel dimensions comply with standard TO-92 taping specifications, including carrier tape width (0.708"), sprocket hole diameter (0.157"), and feed pitch (0.500"), ensuring compatibility with automated pick-and-place equipment used in high-volume manufacturing of assemblies containing the MPS6531.

What is the thermal resistance from junction to ambient (R_θJA) for the MPS6531 in its TO-92 package?

The MPS6531 has a specified R_θJA of 200 °C/W when mounted on a standard FR-4 PCB with no copper pour. This value reflects worst-case natural convection cooling and serves as the baseline for thermal design calculations. For higher-power operation, designers may improve thermal performance by adding copper pads or thermal vias-though the MPS6531's 625 mW dissipation limit at 25°C remains the primary constraint.