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

onsemi 2N2102

Name: 2N2102
Brand: onsemi
SKU: 2N2102
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2N2102

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-205AA, TO-5-3 Metal Can

Datasheet:: 2N2102.pdf

Description:: TRANS PNP 65V 1A TO-5

Quantity:: RFQ Add To RFQ list

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Product details

Overview

2N2102 from STMicroelectronics is a silicon planar epitaxial NPN bipolar junction transistor in TO-39 metal package, rated for 65 V V_CEO, 1 A I_C, and 1.5 W P_tot at T_amb ≤ 25 °C, used as general-purpose amplifier and switch in industrial and military small-signal and medium-power circuits.

For engineers reviewing the 2N2102 datasheet, 2N2102 pinout, 2N2102 application, or 2N2102 equivalent, key selection criteria include V_CEO = 65 V, h_FE = 10–120 (I_C = 10 µA to 1 A), f_T ≈ 60 MHz (inferred from h_fe = 6 at 20 MHz), low noise figure (8 dB @ 1 kHz), and TO-39 thermal resistance (R_thj-case = 30 °C/W).

Technical Context

This NPN BJT operates with base-emitter forward bias controlling collector current in linear amplification or saturated switching modes. Its 175 °C max junction temperature and 150 °C/W R_thj-amb support operation in thermally constrained industrial enclosures without forced cooling.

Designed for DC-coupled and RF-amplifier stages up to ~20 MHz, it delivers h_fe = 6 at 20 MHz and low C_CBO = 15 pF, enabling stable gain in tuned amplifiers and reliable switching with t_on/t_off suitable for <100 kHz pulse applications.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	65 V - Maximum safe collector-emitter voltage under open-base condition; defines upper rail limit in amplifier/saturation-switch designs.
I_C	1 A - Continuous collector current rating; supports medium-power load driving up to ~65 W at full V_CEO.
P_tot	1.5 W at T_amb ≤ 25 °C - Thermal power limit requiring heatsinking above ambient; R_thj-case = 30 °C/W enables direct mounting to chassis.
h_FE	10–120 - Wide DC current gain range across I_C = 10 µA to 1 A; allows flexible biasing for low-current sensing or high-current switching.
f_T	≈60 MHz - Estimated transition frequency (from h_fe = 6 @ 20 MHz); supports audio and low-MHz RF amplification with stable gain.
NF	8 dB @ 1 kHz - Measured noise figure with R_g = 510 Ω; suitable for preamplifier stages where signal integrity matters.

Pinout & Package

TO-39 metal can package with hermetically sealed construction, 3-pin layout, and case-connected collector for direct thermal and electrical grounding. Dimensions per JEDEC MS-001 (A = 12.7 mm, D = 6.6 mm, E = 8.5 mm, F = 9.4 mm).

Pin/Terminal	Circuit Role	Design Meaning
Emitter (E)	Current sink terminal	Low-impedance output node in common-emitter configuration; connects to ground or negative rail in most amplifier/switch layouts.
Base (B)	Control input terminal	Receives current-limited drive (e.g., via 1–10 kΩ resistor) to set operating point; sensitive to ESD due to thin oxide layer.
Collector (C)	Current source terminal	Internally connected to metal case; must be electrically isolated from heatsink unless referenced to system ground.

Key Features

Feature	Design Value
Hermetic TO-39 metal package	Enables operation in harsh environments (military/industrial) with guaranteed long-term parameter stability and moisture resistance.
175 °C max junction temperature	Permits sustained operation in unventilated enclosures or near heat-generating components without derating below 125 °C ambient.
V_CER = 80 V (R_BE ≤ 10 Ω)	Supports safe switching of inductive loads with base-clamped turn-off, reducing risk of secondary breakdown during flyback events.
Low C_EBO = 80 pF	Minimizes Miller effect in high-gain CE stages; improves bandwidth predictability in multi-stage amplifiers.

Applications

Industrial Power Supply Control

Military Radio Frequency Amplifier

Use Scenario: Regulating feedback loop in 24–48 V DC-DC converters using discrete transistor-based error amplifiers.

IC Role / Device Role / Timing Role: NPN transconductance amplifier providing precise V_ref error correction with h_FE-stable bias.

Use Value: 65 V V_CEO accommodates transient spikes on 48 V rails; 1.5 W dissipation handles continuous 100 mA error current.

Use Scenario: First-stage low-noise RF amplifier in HF/VHF transceiver front-end (1–30 MHz).

IC Role / Device Role / Timing Role: Common-emitter small-signal amplifier with grounded emitter and tuned collector load.

Use Value: 8 dB NF at 1 kHz and 15 pF C_CBO enable high SNR in weak-signal reception; TO-39 shielding reduces EMI coupling.

Automotive Ignition Driver

Test Equipment Signal Generator Stage

Use Scenario: Driving ignition coil primary winding in legacy distributor-based engine control units.

IC Role / Device Role / Timing Role: Saturated switch turning coil current on/off with fast t_on/t_off and V_CE(sat) = 0.5 V.

Use Value: V_CER = 80 V withstands 300 V+ flyback spikes when coil is de-energized; 175 °C T_j survives under-hood temperatures.

Use Scenario: Output buffer stage in benchtop function generator delivering ±10 V, 100 mA sine/triangle waveforms.

IC Role / Device Role / Timing Role: Class-A linear amplifier biased at 500 mA for low-distortion output swing.

Use Value: h_FE = 25 @ I_C = 500 mA ensures predictable bias stability; TO-39 case provides mechanical rigidity and thermal mass.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
2N2219A	V_CEO = 40 V, P_tot = 1.8 W, TO-39, h_FE = 50–250 @ I_C = 150 mA	Lower voltage rating limits use in >40 V systems; higher h_FE eases base drive design.	Select when lower V_CEO suffices and higher DC gain is preferred over voltage margin.
BC548B	V_CEO = 30 V, P_tot = 0.5 W, TO-92, h_FE = 200–450 @ I_C = 2 mA	Plastic package, lower power/voltage; unsuitable for >30 V or >500 mW applications.	Choose only for low-voltage, low-power signal amplification where TO-39 ruggedness is unnecessary.

Compared with 2N2102, 2N2219A trades voltage headroom for higher gain and slightly higher power, while BC548B offers cost-effective plastic-packaged amplification at significantly reduced voltage, power, and thermal capability-neither matches the 2N2102's 65 V/1.5 W/TO-39 combination for demanding industrial switching.

Availability

2N2102 is available at Aetrix Electronics and suitable for industrial power supply control, military radio frequency amplifiers, automotive ignition drivers, and test equipment signal generator stages requiring stable component supply despite its obsolete status.

Supply support for 2N2102 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The 2N2102 belongs to ST's legacy bipolar transistor product line, engineered for reliability-critical analog amplification and switching in military-grade and high-temperature industrial equipment.

FAQ

Is the 2N2102 still in active production?

No, the 2N2102 is marked "Obsolete Product(s)" in ST's official documentation (Rev. December 2002). It is no longer manufactured but remains available through authorized legacy distributors and Aetrix Electronics' long-life inventory with full traceability and testing verification.

Can the 2N2102 be used as a direct replacement for the 2N2222?

No-it is not a drop-in replacement. The 2N2222 has V_CEO = 40 V and P_tot = 0.5 W in TO-18, whereas the 2N2102 offers 65 V and 1.5 W in TO-39. Pinout differs (2N2222: E-B-C; 2N2102: E-B-C but case-connected collector), requiring PCB and thermal redesign.

What is the maximum safe switching frequency for the 2N2102?

While not explicitly specified, its h_fe = 6 at 20 MHz implies usable switching up to ~100 kHz in saturated mode. For linear amplification, bandwidth is limited by f_T ≈ 60 MHz and circuit parasitics; practical RF use is confirmed up to 30 MHz per military application notes.

Does the metal TO-39 case require electrical isolation from the heatsink?

Yes-the collector is internally bonded to the case. If the collector node is not at chassis ground potential, the case must be electrically insulated using mica washers or silicone pads to prevent short circuits, especially in floating or negative-rail configurations.

2N2102 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-205AA, TO-5-3 Metal Can

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 1 A

Voltage - Collector Emitter Breakdown (Max):: 65 V

Vce Saturation (Max) @ Ib, Ic:: -

Current - Collector Cutoff (Max):: -

DC Current Gain (hFE) (Min) @ Ic, Vce:: -

Power - Max:: -

Frequency - Transition:: -

Operating Temperature:: -

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-5

2N2102 FAQ

1.How can I place an order for 2N2102 through Aetrix?

Please submit a Request for Quotation (RFQ) for 2N2102 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 2N2102 reliable?

The price and inventory of 2N2102 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2N2102 is usually 5 days.

3.What payment methods are accepted for 2N2102?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2N2102 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2N2102?

2N2102 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2N2102 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 2N2102?

For technical support, including 2N2102 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2N2102 requirements.

6.How does Aetrix verify that 2N2102 is sourced from the original manufacturer or authorized distributors?

All 2N2102 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 2N2102 meets industry standards.

7.What is the process for return or replacement of 2N2102?

All 2N2102 units undergo pre-shipment inspection (PSI). If there is an issue with 2N2102, 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 2N2102 part is unused and in its original packaging.

Return procedure for 2N2102:

1.Submit a request within 90 days.

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

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