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 2N3906_J18Z

Name: 2N3906_J18Z
Brand: onsemi
SKU: 2N3906_J18Z
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: 2N3906_J18Z

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: 2N3906_J18Z.pdf

Description:: TRANS PNP 40V 0.2A TO-92-3

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:8,242

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

Product details

Overview

2N3906_J18Z from onsemi is a PNP bipolar junction transistor (BJT) designed for general-purpose amplification and switching at collector currents from 10 mA to 100 mA. It features V_CEO = −40 V, I_C = −200 mA continuous, h_FE = 100–300 at I_C = −10 mA, and V_CE(sat) = −0.25 V at I_C = −10 mA/I_B = −1 mA - enabling reliable low-voltage logic-level switching in discrete power control circuits.

For engineers reviewing the 2N3906_J18Z datasheet, pinout, applications, or equivalent options, key selection considerations include its TO-92 package with E-B-C terminal order, −40 V breakdown rating, thermal resistance of R_θJA = 200 °C/W, and suitability for linear amplification, level translation, and active-load switching in industrial sensor interfaces and legacy analog subsystems.

Technical Context

The 2N3906_J18Z operates as a standard PNP BJT with fixed-emitter biasing topology, supporting common-emitter and common-base configurations. Its f_T = 250 MHz enables stable operation up to audio and low-RF frequencies, while C_obo = 4.5 pF and C_ibo = 10.0 pF define small-signal input/output capacitance behavior under reverse-biased conditions.

Switching performance is characterized by t_d = 35 ns, t_r = 35 ns, t_s = 225 ns, and t_f = 75 ns at V_CC = −3.0 V and I_C = −10 mA - indicating moderate-speed digital switching capability limited primarily by storage time due to minority-carrier lifetime in the base region.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−40 V - Maximum allowable collector-to-emitter voltage before breakdown; defines safe operating range in high-side switch or amplifier bias designs.
I_C (max)	−200 mA - Continuous collector current limit; supports medium-current load driving without forced cooling.
h_FE	100–300 at I_C = −10 mA - DC current gain range enabling predictable base drive sizing for saturation or linear operation.
V_CE(sat)	−0.25 V at I_C = −10 mA / I_B = −1 mA - Low saturation voltage minimizes conduction loss in switching applications.
f_T	250 MHz - Unity-gain bandwidth confirming usable frequency response up to mid-VHF for small-signal amplification.
R_θJA	200 °C/W - Junction-to-ambient thermal resistance in TO-92 package; determines maximum power dissipation at given ambient temperature.

Pinout & Package

2N3906_J18Z is housed in a TO-92 3-lead through-hole plastic package with straight lead configuration (J61Z option per Figure 17), compliant with JEDEC TO-92 standards. The device uses E-B-C (Emitter-Base-Collector) pin order when viewed with flat side facing outward and leads pointing downward.

Pin/Terminal	Circuit Role	Design Meaning
Lead 1 (left)	Emitter (E)	Current sink node; connects to higher potential rail in PNP high-side switch or bias network reference point.
Lead 2 (center)	Base (B)	Control terminal; requires negative current injection relative to emitter to turn on; typical R_B = 10 kΩ for logic-driven switching.
Lead 3 (right)	Collector (C)	Output current path; connects to load and supply return; must remain ≤ V_E − 40 V to avoid avalanche.

Key Features

Feature	Design Value
PNP polarity with −40 V V_CEO	Enables high-side switching in 3.3 V/5 V systems where emitter ties to V_CC and collector drives grounded loads.
h_FE ≥ 100 at I_C = −10 mA	Reduces required base drive current, easing interface with microcontroller GPIO or logic gates without external buffer stages.
V_CE(sat) ≤ −0.25 V	Limits power loss to <2.5 mW at 10 mA load, supporting thermally constrained PCB layouts in compact analog modules.
f_T = 250 MHz	Supports clean amplification of audio-band signals (≤20 kHz) with ample gain margin and minimal phase shift.
TO-92 mechanical compatibility	Ensures drop-in replacement in legacy through-hole designs using standard 0.1″ pitch prototyping and production tooling.

Applications

Industrial Sensor Signal Conditioning	Legacy Microcontroller I/O Level Translation
Use Scenario: Amplifying low-level output from resistive temperature detectors (RTDs) or strain gauges in 24 V industrial PLC input modules. IC Role / Device Role / Timing Role: Discrete PNP amplifier in common-emitter configuration with emitter-degeneration bias for stable DC gain and noise rejection. Use Value: Delivers h_FE-stabilized gain >100 with NF = 4.0 dB at 100 μA, enabling sub-mV signal resolution without op-amp complexity.	Use Scenario: Converting 3.3 V logic-high outputs from ARM Cortex-M MCUs to −5 V or −12 V levels required by legacy RS-232 transceivers or analog multiplexers. IC Role / Device Role / Timing Role: Active pull-up switch configured as emitter-follower with base driven by MCU GPIO. Use Value: Achieves <100 ns propagation delay and <0.25 V saturation drop, preserving timing margins in full-duplex serial communication paths.
Discrete Power Supply Enable Control	Analog Front-End Load Switching
Use Scenario: Enabling/disabling auxiliary 12 V rails in programmable power supplies using microcontroller PWM signals. IC Role / Device Role / Timing Role: High-side switch with base resistor network and flyback diode protection for inductive loads. Use Value: Handles −200 mA continuous current with R_θJA = 200 °C/W, allowing operation up to +70 °C ambient without heatsinking.	Use Scenario: Isolating precision DAC output stages from varying load impedances in test equipment front-ends. IC Role / Device Role / Timing Role: Current-source buffer in common-base configuration to maintain constant output impedance. Use Value: Provides h_fe-independent current mirroring accuracy via matched V_BE tracking and low C_obo = 4.5 pF for minimal capacitive loading.

Industrial Sensor Signal Conditioning

Legacy Microcontroller I/O Level Translation

Use Scenario: Amplifying low-level output from resistive temperature detectors (RTDs) or strain gauges in 24 V industrial PLC input modules.

IC Role / Device Role / Timing Role: Discrete PNP amplifier in common-emitter configuration with emitter-degeneration bias for stable DC gain and noise rejection.

Use Value: Delivers h_FE-stabilized gain >100 with NF = 4.0 dB at 100 μA, enabling sub-mV signal resolution without op-amp complexity.

Use Scenario: Converting 3.3 V logic-high outputs from ARM Cortex-M MCUs to −5 V or −12 V levels required by legacy RS-232 transceivers or analog multiplexers.

IC Role / Device Role / Timing Role: Active pull-up switch configured as emitter-follower with base driven by MCU GPIO.

Use Value: Achieves <100 ns propagation delay and <0.25 V saturation drop, preserving timing margins in full-duplex serial communication paths.

Discrete Power Supply Enable Control

Analog Front-End Load Switching

Use Scenario: Enabling/disabling auxiliary 12 V rails in programmable power supplies using microcontroller PWM signals.

IC Role / Device Role / Timing Role: High-side switch with base resistor network and flyback diode protection for inductive loads.

Use Value: Handles −200 mA continuous current with R_θJA = 200 °C/W, allowing operation up to +70 °C ambient without heatsinking.

Use Scenario: Isolating precision DAC output stages from varying load impedances in test equipment front-ends.

IC Role / Device Role / Timing Role: Current-source buffer in common-base configuration to maintain constant output impedance.

Use Value: Provides h_fe-independent current mirroring accuracy via matched V_BE tracking and low C_obo = 4.5 pF for minimal capacitive loading.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MMBT3906	SOT-23 surface-mount package; R_θJA = 357 °C/W; same electrical specs except lower PD = 350 mW.	Requires PCB redesign for SMT assembly; unsuitable for through-hole prototyping or high-power dissipation (>150 mW).	Select MMBT3906 only when board space constraints mandate SMT and thermal budget permits derated power handling.
PZT3906	SOT-223-4L package with exposed thermal pad; PD = 1000 mW; R_θJA = 125 °C/W; identical electrical characteristics.	Supports higher continuous current (−200 mA at elevated ambient) but requires 4-pin footprint and thermal land pattern.	Choose PZT3906 when sustained −200 mA operation above +50 °C ambient is required and thermal pad layout is feasible.

Compared with MMBT3906 and PZT3906, the 2N3906_J18Z offers optimal balance of legacy TO-92 compatibility, 625 mW power dissipation, and standardized pinout - making it the preferred choice for service replacements, educational labs, and cost-sensitive through-hole production where thermal demands do not exceed 70 °C ambient.

Availability

2N3906_J18Z is available at Aetrix Electronics and suitable for industrial sensor interfaces, legacy microcontroller I/O conditioning, and discrete power supply enable control requiring stable component supply across long-lifecycle embedded programs.

Supply support for 2N3906_J18Z 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier delivering energy-efficient silicon solutions for automotive, industrial, cloud, medical, and IoT applications.

The 2N3906_J18Z belongs to onsemi's legacy general-purpose transistor family, engineered for reliability and consistency in discrete analog signal conditioning and switching functions across decades of industrial design cycles.

FAQ

What is the pin configuration of the 2N3906_J18Z?

The 2N3906_J18Z uses a TO-92 package with E-B-C (Emitter-Base-Collector) pin order when viewed with the flat side facing outward and leads pointing downward. Lead 1 (left) is Emitter, Lead 2 (center) is Base, and Lead 3 (right) is Collector - matching JEDEC TO-92 standard orientation for direct replacement in legacy designs.

Does the 2N3906_J18Z support switching applications?

Yes, the 2N3906_J18Z supports switching applications with verified parameters: t_d = 35 ns, t_r = 35 ns, t_s = 225 ns, and t_f = 75 ns at I_C = −10 mA. Its V_CE(sat) = −0.25 V at I_C/I_B = −10 mA/−1 mA ensures low conduction loss, making it suitable for medium-speed digital logic interfacing and power rail control.

What is the maximum power dissipation of the 2N3906_J18Z?

The 2N3906_J18Z has a total device dissipation (P_D) of 625 mW at T_A = 25°C, with a thermal derating factor of 5.0 mW/°C above that temperature. This allows up to ~500 mW dissipation at +50°C ambient when mounted on standard FR-4 PCB, sufficient for most linear amplifier and switching roles in non-ventilated enclosures.

Can the 2N3906_J18Z replace the MMBT3906 in a circuit?

The 2N3906_J18Z can replace the MMBT3906 electrically but not mechanically: both share identical V_CEO, h_FE, and V_CE(sat) specs, yet the 2N3906_J18Z uses TO-92 through-hole packaging versus SOT-23 surface-mount. PCB layout changes are required, and thermal performance differs (R_θJA = 200 vs. 357 °C/W), so power handling must be re-evaluated.

What is the noise figure of the 2N3906_J18Z and where is it specified?

The 2N3906_J18Z has a noise figure (NF) of 4.0 dB measured at I_C = −100 μA, V_CE = −5.0 V, R_S = 1.0 kΩ, and frequency range 10 Hz to 15.7 kHz - per onsemi's PZT3906/D datasheet Figure 7 and Electrical Characteristics table. This makes it suitable for low-noise preamplifier stages in sensor signal chains.

2N3906_J18Z 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:: PNP

Current - Collector (Ic) (Max):: 200 mA

Voltage - Collector Emitter Breakdown (Max):: 40 V

Vce Saturation (Max) @ Ib, Ic:: 400mV @ 5mA, 50mA

Current - Collector Cutoff (Max):: -

DC Current Gain (hFE) (Min) @ Ic, Vce:: 100 @ 10mA, 1V

Power - Max:: 625 mW

Frequency - Transition:: 250MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

2N3906_J18Z FAQ

1.How can I place an order for 2N3906_J18Z through Aetrix?

Please submit a Request for Quotation (RFQ) for 2N3906_J18Z 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 2N3906_J18Z reliable?

The price and inventory of 2N3906_J18Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2N3906_J18Z is usually 5 days.

3.What payment methods are accepted for 2N3906_J18Z?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2N3906_J18Z transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2N3906_J18Z?

2N3906_J18Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2N3906_J18Z 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 2N3906_J18Z?

For technical support, including 2N3906_J18Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2N3906_J18Z requirements.

6.How does Aetrix verify that 2N3906_J18Z is sourced from the original manufacturer or authorized distributors?

All 2N3906_J18Z 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 2N3906_J18Z meets industry standards.

7.What is the process for return or replacement of 2N3906_J18Z?

All 2N3906_J18Z units undergo pre-shipment inspection (PSI). If there is an issue with 2N3906_J18Z, 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 2N3906_J18Z part is unused and in its original packaging.

Return procedure for 2N3906_J18Z:

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…