Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Single Bipolar Transistors

onsemi 2N5961

Name: 2N5961
Brand: onsemi
SKU: 2N5961
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: 2N5961

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-226-3, TO-92-3 (TO-226AA)

Datasheet:: 2N5961.pdf

Description:: TRANS NPN 60V 0.1A TO-92-3

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:6,908

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

2N5961 from Fairchild Semiconductor is an NPN general-purpose amplifier optimized for low-noise, high-gain signal amplification up to 50 mA collector current, with V_CEO = 60 V, h_FE ≥ 100 (at I_C = 10 µA), and noise figure of 3.0 dB at 1 kHz - used in preamplifier stages of audio and instrumentation circuits.

For engineers reviewing the 2N5961 datasheet, pinout, applications, or equivalent options, key selection criteria include its TO-92 package, low-noise performance at microamp bias currents, thermal resistance of 200 °C/W, and compatibility with low-voltage, low-power analog front-ends requiring stable h_FE across I_C = 10 µA to 10 mA.

Technical Context

The 2N5961 operates as a discrete silicon NPN bipolar junction transistor fabricated in Fairchild's Process 07, targeting linear amplification rather than switching. Its design emphasizes low base-emitter voltage (V_BE(on) = 0.5–0.7 V) and high DC current gain (h_FE up to 700) at low collector currents, supporting precision biasing in multi-stage amplifiers.

It exhibits low capacitance (C_cb = 4.0 pF, C_eb = 6.0 pF) and specified noise performance (NF = 3.0 dB @ 1 kHz), confirming suitability for small-signal amplification where bandwidth and SNR are critical - not intended for RF power or digital switching applications.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	60 V - maximum safe collector-emitter voltage before breakdown; sets rail limit for single-supply amplifier stages.
I_C (max)	100 mA - continuous collector current rating; supports headroom for transient peaks beyond nominal 50 mA operation.
h_FE	100–700 - DC current gain range across I_C = 10 µA to 10 mA; enables stable bias design in emitter-degenerated configurations.
NF	3.0 dB @ 1 kHz - measured noise figure with 10 kΩ source; confirms low-noise capability for sensor interface preamps.
R_θJA	200 °C/W - junction-to-ambient thermal resistance in free-air; defines max power dissipation (625 mW) at 25°C ambient.
C_cb	4.0 pF - collector-base capacitance at 5 V; limits high-frequency gain roll-off and stability margin in feedback amplifiers.

Pinout & Package

2N5961 is housed in a standard TO-92 plastic package with 3 leads, rated for ≤625 mW total dissipation and operating from –55°C to +150°C. Pin identification follows JEDEC TO-92 outline: Emitter (lead 1), Base (lead 2), Collector (lead 3), with flat side facing viewer and leads down.

Pin/Terminal	Circuit Role	Design Meaning
E (Lead 1)	Emitter	Current sink terminal; connects to ground or emitter resistor for bias stabilization and AC signal return path.
B (Lead 2)	Base	Control input; requires precise DC bias (e.g., voltage divider) to set operating point within h_FE-dependent I_C range.
C (Lead 3)	Collector	Output node; delivers amplified current to load or next stage; must remain ≤60 V below emitter under all conditions.

Key Features

Feature	Design Value
Low-noise amplification	3.0 dB NF at 1 kHz enables high-fidelity signal conditioning in microphone and transducer preamps.
High DC current gain	h_FE ≥ 100 at I_C = 10 µA supports stable biasing in ultra-low-power analog sensors.
Controlled breakdown ratings	V_CEO = V_CBO = 60 V ensures symmetric voltage handling in common-emitter and common-base topologies.
Thermal robustness	Junction temperature range of –55°C to +150°C allows use in industrial and automotive under-hood environments.

Applications

Audio Preamplifier Stage	Instrumentation Signal Conditioning
Use Scenario: Amplifying weak signals from dynamic microphones or piezoelectric sensors before ADC sampling. IC Role / Device Role / Timing Role: Low-noise NPN amplifier in common-emitter configuration with emitter degeneration. Use Value: 3.0 dB noise figure and h_FE ≥ 150 at I_C = 1.0 mA preserve SNR in sub-mV input ranges.	Use Scenario: Front-end gain stage in portable multimeters or data loggers measuring thermocouple or strain gauge outputs. IC Role / Device Role / Timing Role: Linear amplifier with stable h_FE over temperature for calibrated DC gain accuracy. Use Value: V_CEO = 60 V and R_θJA = 200 °C/W allow reliable operation with ±15 V rails and ambient up to 70°C.
Low-Power Sensor Interface	Discrete Op-Amp Input Pair
Use Scenario: Biasing and amplifying output of photodiode or Hall-effect sensors in battery-powered IoT nodes. IC Role / Device Role / Timing Role: High-gain, low-I_C active load in transimpedance or differential pair configurations. Use Value: h_FE ≥ 120 at I_C = 100 µA enables nanoamp-level input current amplification without external bias networks.	Use Scenario: Building discrete-input differential amplifiers where matched h_FE and low C_cb improve CMRR and bandwidth. IC Role / Device Role / Timing Role: Complementary NPN pair (with matching PNP) in discrete op-amp input stage. Use Value: C_cb = 4.0 pF and C_eb = 6.0 pF minimize Miller effect, supporting >10 MHz small-signal bandwidth.

Audio Preamplifier Stage

Instrumentation Signal Conditioning

Use Scenario: Amplifying weak signals from dynamic microphones or piezoelectric sensors before ADC sampling.

IC Role / Device Role / Timing Role: Low-noise NPN amplifier in common-emitter configuration with emitter degeneration.

Use Value: 3.0 dB noise figure and h_FE ≥ 150 at I_C = 1.0 mA preserve SNR in sub-mV input ranges.

Use Scenario: Front-end gain stage in portable multimeters or data loggers measuring thermocouple or strain gauge outputs.

IC Role / Device Role / Timing Role: Linear amplifier with stable h_FE over temperature for calibrated DC gain accuracy.

Use Value: V_CEO = 60 V and R_θJA = 200 °C/W allow reliable operation with ±15 V rails and ambient up to 70°C.

Low-Power Sensor Interface

Discrete Op-Amp Input Pair

Use Scenario: Biasing and amplifying output of photodiode or Hall-effect sensors in battery-powered IoT nodes.

IC Role / Device Role / Timing Role: High-gain, low-I_C active load in transimpedance or differential pair configurations.

Use Value: h_FE ≥ 120 at I_C = 100 µA enables nanoamp-level input current amplification without external bias networks.

Use Scenario: Building discrete-input differential amplifiers where matched h_FE and low C_cb improve CMRR and bandwidth.

IC Role / Device Role / Timing Role: Complementary NPN pair (with matching PNP) in discrete op-amp input stage.

Use Value: C_cb = 4.0 pF and C_eb = 6.0 pF minimize Miller effect, supporting >10 MHz small-signal bandwidth.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
2N5088	Same Process 07 family; identical V_CEO, V_CBO, and h_FE specs; slightly lower NF (2.5 dB) but same TO-92 package.	Preferred where lowest possible noise is required at I_C < 100 µA; otherwise functionally interchangeable.	Select 2N5088 when NF < 3.0 dB is mandatory; otherwise 2N5961 offers identical gain and voltage ratings with broader availability.
BC547B	Higher max I_C (100 mA vs. 50 mA typical), lower h_FE min (200 vs. 100), and higher C_cb (5 pF); TO-92 compatible but not process-matched.	Better suited for general-purpose switching or medium-gain amplification; less optimal for ultra-low-noise preamp use.	Choose BC547B only if higher current drive or cost sensitivity outweighs noise and gain consistency requirements.

Compared with 2N5088 and BC547B, the 2N5961 provides the best balance of verified low-noise performance, high h_FE at microamp bias, and documented thermal reliability - making it preferred for precision analog front-ends where gain stability and SNR are design-critical.

Availability

2N5961 is available at Aetrix Electronics and suitable for audio preamplifier stages, instrumentation signal conditioning, and low-power sensor interfaces requiring stable component supply and long-term obsolescence management.

Supply support for 2N5961 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 analog, discrete, and power ICs before its acquisition by ON Semiconductor in 2016; known for high-reliability bipolar transistors and legacy process technologies.

The 2N5961 belongs to Fairchild's legacy "2N" series of general-purpose NPN transistors designed specifically for low-noise, high-gain linear amplification in industrial and test equipment - not optimized for switching speed or power efficiency.

FAQ

What is the maximum collector-emitter voltage rating for the 2N5961?

The 2N5961 has a maximum collector-emitter voltage (V_CEO) rating of 60 V at T_A = 25°C. This rating is based on a maximum junction temperature of 150°C and applies under steady-state DC conditions. Operation above this voltage risks irreversible breakdown, and pulsed applications require consultation with Fairchild's factory per datasheet Note 2.

Does the 2N5961 support low-noise operation at microamp collector currents?

Yes, the 2N5961 is characterized for low-noise operation at I_C = 10 µA, delivering a noise figure of 3.0 dB with R_S = 10 kΩ at 1 kHz and 400 Hz bandwidth. This performance is explicitly documented in the "SMALL SIGNAL CHARACTERISTICS" table of the official Fairchild datasheet, confirming its suitability for ultra-low-current preamplifier designs.

What package type is used for the 2N5961, and how are its pins arranged?

The 2N5961 uses a TO-92 plastic package with three leads. When viewing the flat side of the device with leads pointing downward, the pin order from left to right is Emitter (lead 1), Base (lead 2), and Collector (lead 3). This configuration is confirmed in Fairchild's TO-92 packaging documentation and matches JEDEC standard outline TO-92.

How does the 2N5961 compare to the 2N5088 in terms of noise and gain?

The 2N5961 and 2N5088 share the same Process 07 fabrication and identical absolute maximum ratings. The 2N5088 has a slightly lower typical noise figure (2.5 dB vs. 3.0 dB), while both specify h_FE ≥ 100 at I_C = 10 µA. The 2N5961 datasheet explicitly references the 2N5088 for characteristics, confirming functional equivalence except for minor NF variation.

Is the 2N5961 suitable for use in automotive under-hood environments?

The 2N5961 supports an operating junction temperature range of –55°C to +150°C and has a thermal resistance R_θJA of 200 °C/W. While its specifications meet extended temperature requirements, Fairchild's datasheet includes no AEC-Q101 qualification statement. Therefore, the 2N5961 may be used in non-safety-critical automotive ambient zones only after full system-level validation - it is not certified for life-support or safety-critical automotive functions.

2N5961 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 (TO-226AA)

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 100 mA

Voltage - Collector Emitter Breakdown (Max):: 60 V

Vce Saturation (Max) @ Ib, Ic:: 200mV @ 500µA, 10mA

Current - Collector Cutoff (Max):: 2nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 150 @ 10mA, 5V

Power - Max:: 625 mW

Frequency - Transition:: -

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

2N5961 FAQ

1.How can I place an order for 2N5961 through Aetrix?

Please submit a Request for Quotation (RFQ) for 2N5961 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for 2N5961 reliable?

The price and inventory of 2N5961 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2N5961 is usually 5 days.

3.What payment methods are accepted for 2N5961?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2N5961 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2N5961?

2N5961 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2N5961 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for 2N5961?

For technical support, including 2N5961 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2N5961 requirements.

6.How does Aetrix verify that 2N5961 is sourced from the original manufacturer or authorized distributors?

All 2N5961 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 2N5961 meets industry standards.

7.What is the process for return or replacement of 2N5961?

All 2N5961 units undergo pre-shipment inspection (PSI). If there is an issue with 2N5961, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The 2N5961 part is unused and in its original packaging.

Return procedure for 2N5961:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

Tech Hub

2026-09-09 Counterfeit Electronic Components: How to Detect, Authenticate, and Test Suspect Parts

Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…