onsemi MMBT5210

Overview

MMBT5210 from Fairchild Semiconductor is an NPN general-purpose amplifier optimized for low-noise, high-gain analog signal amplification at collector currents from 1 µA to 50 mA. It features V_CEO = 50 V, h_FE = 250–600 (at I_C = 1–10 mA), f_T = 30 MHz, and NF = 2.0–3.0 dB in audio-band noise-critical applications such as preamplifier stages in portable audio receivers.

For engineers reviewing the MMBT5210 datasheet, pinout, applications, or equivalent options, key selection criteria include its SOT-23 package thermal resistance (R_θJA = 357 °C/W), low V_BE(on) = 0.85 V at I_C = 1 mA, and verified noise performance under 22 kΩ source impedance at 10 Hz–15.7 kHz bandwidth.

Technical Context

The MMBT5210 operates as a silicon NPN bipolar junction transistor with fixed-emitter biasing capability and common-emitter configuration suitability. Its design emphasizes stable DC current gain across temperature (±25% variation from −40°C to +125°C) and predictable small-signal parameters including h_fe = 250–900 and C_cb = 4.0 pF at V_CB = 5.0 V.

Thermal derating is defined at 2.8 mW/°C above 25°C ambient, with maximum power dissipation of 350 mW in SOT-23. Junction-to-ambient thermal resistance (357 °C/W) reflects its surface-mount thermal limitation, requiring careful PCB copper area planning for sustained >10 mA operation.

Key Specifications

Pinout & Package

SOT-23 plastic surface-mount package (marking: "3M"), with standardized lead frame geometry and JEDEC MO-215 compliant footprint. Thermal pad not present; solder joint thermal conduction relies on trace copper area.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC847B and MPSA18, the MMBT5210 offers superior noise performance and highest h_FE range in SOT-23, making it optimal for space-constrained, low-noise analog signal chains where thermal management permits 350 mW operation.

Availability

MMBT5210 is available at Aetrix Electronics and suitable for audio preamplifier stages, DC-coupled sensor interfaces, low-voltage logic level shifters, and RF detector bias stages requiring stable component supply across production lifecycles.

Supply support for MMBT5210 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 devices before its acquisition by ON Semiconductor in 2016.

The MMBT5210 belongs to Fairchild's general-purpose NPN transistor product line, designed specifically for low-noise, medium-gain analog amplification in consumer, industrial, and communications equipment.

FAQ

What is the maximum continuous collector current rating for the MMBT5210?

The MMBT5210 has a maximum continuous collector current (I_C) rating of 100 mA per Absolute Maximum Ratings. However, due to its 350 mW power dissipation limit in SOT-23 and thermal resistance of 357 °C/W, sustained operation above ~10 mA at 25°C ambient requires PCB thermal relief. The MMBT5210 datasheet specifies derating of 2.8 mW/°C above 25°C.

Does the MMBT5210 support operation at elevated temperatures?

Yes, the MMBT5210 is rated for junction temperatures from −55°C to +150°C. Its h_FE, f_T, and noise figure remain functional across this range, with typical h_FE varying ±25% and NF increasing <1 dB from −40°C to +125°C. The MMBT5210 must be mounted on adequate copper area to maintain T_J ≤ 150°C under load.

What is the noise figure specification for the MMBT5210 and under what conditions is it measured?

The MMBT5210 achieves a noise figure of 2.0 dB at I_C = 20 µA, V_CE = 5.0 V, R_S = 22 kΩ, and bandwidth 10 Hz–15.7 kHz. A second condition yields 3.0 dB at R_S = 10 kΩ. These values are measured per standard low-frequency noise test methods and are directly applicable to microphone preamp and sensor interface designs using the MMBT5210.

Is the MMBT5210 pin-compatible with the TO-92 version 2N5210?

No, the MMBT5210 (SOT-23) and 2N5210 (TO-92) share identical electrical specifications but differ in package and pinout. The MMBT5210 uses emitter-base-collector (E-B-C) pin order in SOT-23, whereas the 2N5210 uses collector-base-emitter (C-B-E) in TO-92. PCB layout and footprint must be redesigned when substituting MMBT5210 for 2N5210.

What is the typical current gain (h_FE) of the MMBT5210 at low collector currents?

The MMBT5210 delivers h_FE ≥ 200 at I_C = 100 µA and V_CE = 5.0 V, enabling reliable amplification in ultra-low-power sensor front-ends. This gain remains usable down to I_C = 1 µA, supporting micropower bias networks. The MMBT5210 datasheet confirms this value under standardized test conditions and shows typical pulsed h_FE curves across the full 1 µA–50 mA operating range.