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_D81Z

Name: 2N3906_D81Z
Brand: onsemi
SKU: 2N3906_D81Z
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: 2N3906_D81Z

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: 2N3906_D81Z.pdf

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

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:8,060

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

Product details

Overview

2N3906_D81Z 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 use in low-voltage logic-level interface circuits and discrete amplifier stages.

For engineers reviewing the 2N3906_D81Z datasheet, pinout, applications, or equivalent options, key selection considerations include its TO-92 J61Z lead form (per Figure 17), guaranteed −40 V breakdown ratings, thermal resistance R_θJA = 200 °C/W on FR-4, and verified small-signal f_T = 250 MHz performance under standard test conditions.

Technical Context

The 2N3906_D81Z operates as a silicon PNP BJT with fixed emitter-base and collector-base junctions optimized for linear amplification and saturated switching. Its DC current gain (h_FE) varies predictably with collector current - 100 min at −10 mA, 60 min at −50 mA, and 30 min at −100 mA - supporting stable bias design across mid-current ranges.

Switching behavior is characterized by t_d = 35 ns, t_r = 35 ns, t_s = 225 ns, and t_f = 75 ns under V_CC = −3.0 V, I_C = −10 mA, and I_B1 = I_B2 = −1.0 mA, confirming suitability for moderate-speed digital logic interfacing and pulse generation up to ~1–2 MHz.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−40 V - Maximum safe collector-emitter voltage before breakdown; defines rail compatibility in negative-supply amplifier or switch stages.
I_C (cont.)	−200 mA - Absolute max continuous collector current; sets upper limit for sustained load drive without thermal derating.
h_FE	100–300 at I_C = −10 mA - Confirmed DC current gain range for stable bias point design in Class-A amplifiers or active loads.
V_CE(sat)	−0.25 V at I_C = −10 mA / I_B = −1 mA - Low saturation voltage enables efficient switching with minimal power loss in emitter-follower or level-shift configurations.
f_T	250 MHz - Current-gain bandwidth product measured at I_C = −10 mA, V_CE = −20 V; supports RF amplification up to VHF band edge.
R_θJA	200 °C/W - Junction-to-ambient thermal resistance on standard FR-4 PCB; determines required heatsinking for >125 mW dissipation.

Pinout & Package

2N3906_D81Z uses the TO-92 package with J61Z lead form (0.200″ inline spacing), per ON Semiconductor Figure 17. The device has three terminals in E-B-C order when viewed with flat side facing outward and leads pointing down.

Pin/Terminal	Circuit Role	Design Meaning
E (Emitter)	Current source terminal for PNP operation	Connected to higher potential (e.g., V_CC or bias rail); defines reference node for base control and collector current sourcing.
B (Base)	Control input for minority-carrier injection	Receives reverse-biased current to turn on transistor; requires −0.65 V to −0.85 V V_BE(sat) for full conduction at I_C = −10 mA.
C (Collector)	Current output/sink terminal	Delivers controlled current to load; must remain ≤ V_E − 40 V to avoid breakdown; used in common-emitter or common-base topologies.

Key Features

Feature	Design Value
Guaranteed V_(BR)CEO ≥ −40 V	Enables reliable operation in −36 V rail systems with 10% safety margin, meeting industrial supply tolerance requirements.
Low V_CE(sat) (−0.25 V)	Reduces conduction loss in high-duty-cycle switching applications such as LED drivers or relay coils, improving efficiency over alternatives with >−0.4 V drop.
f_T = 250 MHz	Supports amplification of signals up to 100 MHz with usable gain, suitable for IF stages in AM/FM receivers and clock buffer circuits.
Verified noise figure ≤ 4.0 dB	Meets low-noise preamplifier requirements in audio and sensor signal conditioning where SNR > 70 dB is critical.

Applications

Audio Preamp Stage	Logic-Level Translator
Use Scenario: Amplifying weak microphone or piezoelectric sensor signals in battery-powered portable audio devices. IC Role / Device Role / Timing Role: Discrete PNP amplifier in common-emitter configuration with emitter degeneration for linearity and gain stability. Use Value: Delivers 20–30 dB voltage gain with <4.0 dB noise figure at 100 μA–1 mA bias, preserving signal integrity in sub-1 V_PP analog paths.	Use Scenario: Converting TTL/CMOS logic-high (3.3 V) to −5 V or −12 V levels for legacy industrial control inputs. IC Role / Device Role / Timing Role: Saturated PNP switch sinking current from negative rail into microcontroller GPIO or optocoupler anode. Use Value: Achieves <35 ns turn-on delay and <75 ns fall time, supporting clean level translation up to 2 MHz without added propagation delay.
Discrete Power Switch	Current Mirror Reference
Use Scenario: Driving small solenoids, relays, or indicator LEDs from microcontroller outputs in automotive body electronics modules. IC Role / Device Role / Timing Role: Low-side PNP switch with base resistor network controlling collector current up to −100 mA. Use Value: Maintains V_CE(sat) ≤ −0.4 V at −50 mA, limiting power dissipation to <20 mW and eliminating need for external heatsinking.	Use Scenario: Building matched current sources in precision analog ICs or sensor front-ends requiring temperature-stable bias currents. IC Role / Device Role / Timing Role: One leg of a two-transistor current mirror with emitter degeneration resistors for improved matching. Use Value: Exhibits h_FE consistency within ±15% across −1 mA to −10 mA, enabling <0.5% current ratio error in well-matched PCB layouts.

Audio Preamp Stage

Logic-Level Translator

Use Scenario: Amplifying weak microphone or piezoelectric sensor signals in battery-powered portable audio devices.

IC Role / Device Role / Timing Role: Discrete PNP amplifier in common-emitter configuration with emitter degeneration for linearity and gain stability.

Use Value: Delivers 20–30 dB voltage gain with <4.0 dB noise figure at 100 μA–1 mA bias, preserving signal integrity in sub-1 V_PP analog paths.

Use Scenario: Converting TTL/CMOS logic-high (3.3 V) to −5 V or −12 V levels for legacy industrial control inputs.

IC Role / Device Role / Timing Role: Saturated PNP switch sinking current from negative rail into microcontroller GPIO or optocoupler anode.

Use Value: Achieves <35 ns turn-on delay and <75 ns fall time, supporting clean level translation up to 2 MHz without added propagation delay.

Discrete Power Switch

Current Mirror Reference

Use Scenario: Driving small solenoids, relays, or indicator LEDs from microcontroller outputs in automotive body electronics modules.

IC Role / Device Role / Timing Role: Low-side PNP switch with base resistor network controlling collector current up to −100 mA.

Use Value: Maintains V_CE(sat) ≤ −0.4 V at −50 mA, limiting power dissipation to <20 mW and eliminating need for external heatsinking.

Use Scenario: Building matched current sources in precision analog ICs or sensor front-ends requiring temperature-stable bias currents.

IC Role / Device Role / Timing Role: One leg of a two-transistor current mirror with emitter degeneration resistors for improved matching.

Use Value: Exhibits h_FE consistency within ±15% across −1 mA to −10 mA, enabling <0.5% current ratio error in well-matched PCB layouts.

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 package (3-pin), R_θJA = 357 °C/W, I_C = −200 mA, same electrical specs but lower power dissipation (350 mW vs. 625 mW).	Preferred for space-constrained PCBs; unsuitable for >150 mW continuous dissipation without thermal relief.	Select MMBT3906 only when board area is critical and thermal budget allows for higher junction temperature rise.
BC807-40	PNP BJT with h_FE = 250–630 at I_C = −100 mA, V_CEO = −45 V, SOT-23 package, higher gain spread and tighter V_CE(sat) spec (−0.3 V max).	Better suited for high-gain, low-saturation switching in automotive gate drivers; not drop-in due to different h_FE distribution.	Choose BC807-40 when designing for higher current gain consistency above −50 mA or stricter V_CE(sat) limits.

Compared with MMBT3906 and BC807-40, the 2N3906_D81Z offers superior thermal performance (625 mW PD, 200 °C/W R_θJA) and proven reliability in through-hole industrial assemblies, making it optimal for legacy-compatible designs requiring mechanical robustness and long-term availability.

Availability

2N3906_D81Z is available at Aetrix Electronics and suitable for industrial control panels, audio signal conditioning circuits, and discrete logic interface modules requiring stable component supply and long-lifecycle support.

Supply support for 2N3906_D81Z 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 specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The 2N3906_D81Z belongs to onsemi's legacy general-purpose BJT product line, engineered for broad compatibility, manufacturability, and long-term reliability in cost-sensitive discrete circuit designs.

FAQ

What is the pin configuration of the 2N3906_D81Z?

The 2N3906_D81Z uses a TO-92 package with J61Z lead form (0.200″ inline spacing). When oriented with the flat side facing the viewer and leads pointing downward, the pin order from left to right is Emitter (E), Base (B), Collector (C). This matches JEDEC TO-92 standard orientation and is confirmed in Figure 17 of the official onsemi datasheet PZT3906/D Rev. 2.

Does the 2N3906_D81Z support switching applications?

Yes, the 2N3906_D81Z is qualified for switching use with documented parameters: t_d = 35 ns, t_r = 35 ns, t_s = 225 ns, and t_f = 75 ns at I_C = −10 mA. These values enable reliable operation in digital logic interfaces, LED drivers, and relay control circuits up to 2 MHz, provided base drive meets −1.0 mA minimum for full saturation.

What is the maximum power dissipation for the 2N3906_D81Z?

The 2N3906_D81Z has a total device dissipation (P_D) of 625 mW at T_A = 25°C, with a derating factor of 5.0 mW/°C above that temperature. This rating applies specifically to the TO-92 package variant and assumes mounting on standard FR-4 PCB per onsemi's thermal test condition (1.6″ × 1.6″ × 0.06″).

Is the 2N3906_D81Z RoHS compliant?

Yes, the 2N3906_D81Z is RoHS compliant and lead-free, consistent with onsemi's corporate compliance policy and the environmental specifications stated in the PZT3906/D datasheet. It meets EU Directive 2011/65/EU and associated exemptions for homogeneous materials.

How does the 2N3906_D81Z compare to the MMBT3906 in terms of thermal performance?

The 2N3906_D81Z delivers significantly better thermal performance than the MMBT3906: R_θJA = 200 °C/W versus 357 °C/W, and P_D = 625 mW versus 350 mW. This means the 2N3906_D81Z can dissipate nearly twice the power under identical ambient conditions, making it preferable for higher-current or thermally constrained applications where the TO-92 footprint is acceptable.

2N3906_D81Z Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

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

Packaging:: Tape & Reel (TR)

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_D81Z FAQ

1.How can I place an order for 2N3906_D81Z through Aetrix?

Please submit a Request for Quotation (RFQ) for 2N3906_D81Z 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_D81Z reliable?

The price and inventory of 2N3906_D81Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2N3906_D81Z is usually 5 days.

3.What payment methods are accepted for 2N3906_D81Z?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2N3906_D81Z transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2N3906_D81Z?

2N3906_D81Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2N3906_D81Z 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_D81Z?

For technical support, including 2N3906_D81Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2N3906_D81Z requirements.

6.How does Aetrix verify that 2N3906_D81Z is sourced from the original manufacturer or authorized distributors?

All 2N3906_D81Z 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_D81Z meets industry standards.

7.What is the process for return or replacement of 2N3906_D81Z?

All 2N3906_D81Z units undergo pre-shipment inspection (PSI). If there is an issue with 2N3906_D81Z, 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_D81Z part is unused and in its original packaging.

Return procedure for 2N3906_D81Z:

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…