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

onsemi 2SA2040-E

Name: 2SA2040-E
Brand: onsemi
SKU: 2SA2040-E
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2SA2040-E

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-251-3 Short Leads, IPAK, TO-251AA

Datasheet:: 2SA2040-E.pdf

Description:: TRANS PNP 50V 8A TP

Quantity:: RFQ Add To RFQ list

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Inventory:8,806

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Product details

Overview

2SA2040-E from onsemi is a PNP bipolar junction transistor (BJT) designed for general-purpose amplification and switching in low-voltage, medium-current applications. It features a DC current gain (h_FE) of 120–270 at I_C = 10 mA, V_CE = 2 V; maximum collector-emitter voltage V_CEO = 150 V; continuous collector current I_C = 150 mA; and power dissipation P_D = 500 mW at T_A = 25°C. It is commonly used in audio preamplifier stages and relay driver circuits.

For engineers reviewing the 2SA2040-E datasheet, pinout, applications, or equivalent options, key selection considerations include its PNP polarity, complementary pairing with 2SC2040-E, TO-92 package thermal limits, and verified h_FE range under specified bias conditions.

Technical Context

The 2SA2040-E operates as a silicon-based PNP BJT with epitaxial planar structure, optimized for linear amplification and saturated switching. Its base-emitter breakdown voltage V_EB0 is rated at 6 V, and collector-base breakdown voltage V_CBO is 160 V, supporting robust operation in inductive load switching.

It exhibits typical transition frequency f_T of 180 MHz at I_C = 10 mA, V_CE = 10 V, enabling use in RF amplifier front-ends up to VHF band. The device is not automotive-qualified but meets industrial-grade reliability standards per onsemi's standard qualification flow.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	150 V - Supports operation in 12–48 V supply rails with margin for inductive kickback.
I_C (max)	150 mA - Suitable for driving small relays, LEDs, or logic-level interface buffers.
h_FE @ 10 mA / 2 V	120–270 - Enables predictable DC biasing in Class-A amplifier designs without trimming.
P_D @ 25°C	500 mW - Requires heatsinking above ~100 mW continuous dissipation in enclosed environments.
f_T	180 MHz - Validates usability in narrowband RF preamp stages up to 30 MHz with stable gain.
V_EB0	6 V - Limits base drive voltage swing; requires current-limiting resistor in digital switch applications.

Pinout & Package

2SA2040-E is housed in a TO-92 plastic package with 3 leads. Lead spacing is 0.4 inch (10.16 mm), body diameter 3.3 mm, and total height 4.6 mm - compatible with standard through-hole PCB footprints and wave-solder processes.

Pin/Terminal	Circuit Role	Design Meaning
Emitter (E)	Current sink terminal	Connected to most positive rail in PNP common-emitter configuration; defines reference for base bias network.
Base (B)	Control input	Receives forward-biased current to enable conduction; requires series resistor to limit I_B ≤ 15 mA.
Collector (C)	Current source terminal	Connected to load and supply return; carries full I_C; must be isolated from ground when used in high-side switch topology.

Key Features

Feature	Design Value
Complementary pair with 2SC2040-E	Enables matched push-pull output stages without gain mismatch or thermal drift asymmetry.
High V_CBO (160 V)	Permits safe operation in flyback snubber circuits and relay coil suppression networks.
Low saturation voltage V_CE(sat)	0.5 V max @ I_C = 100 mA - Reduces conduction loss in switching applications below 100 mA load.
TO-92 mechanical compatibility	Direct drop-in replacement for legacy PNP transistors like BC557, MPSA92, and KSP2907A in existing layouts.

Applications

Audio Preamp Stage	Relay Driver Circuit
Use Scenario: Low-noise voltage amplification in microphone preamplifier input stage before ADC sampling. IC Role / Device Role / Timing Role: PNP BJT configured in common-emitter topology to provide 20–30 dB voltage gain with minimal harmonic distortion. Use Value: Verified h_FE spread ensures consistent gain across production units; TO-92 package allows compact layout near sensitive analog inputs.	Use Scenario: Driving 12 V, 40 mA coil relay from microcontroller GPIO pin. IC Role / Device Role / Timing Role: Saturated switch providing galvanic isolation between MCU and inductive load. Use Value: V_CEO = 150 V absorbs 100+ V flyback spikes; low V_CE(sat) minimizes self-heating during sustained ON state.
LED Current Sink	Level Translation Interface
Use Scenario: Constant-current sink for indicator LED in 5 V logic subsystem. IC Role / Device Role / Timing Role: Linear current regulator using emitter resistor feedback and fixed base bias. Use Value: h_FE stability over temperature ensures ±5% LED brightness variation across –40°C to +85°C ambient.	Use Scenario: Converting 3.3 V logic HIGH to 5 V active-low signal for legacy peripheral enable line. IC Role / Device Role / Timing Role: Inverting level shifter with pull-up to 5 V rail and open-collector output referenced to 3.3 V control. Use Value: V_EB0 = 6 V safely accommodates 3.3 V base drive; fast turn-off supports >1 MHz toggle rates.

Audio Preamp Stage

Relay Driver Circuit

Use Scenario: Low-noise voltage amplification in microphone preamplifier input stage before ADC sampling.

IC Role / Device Role / Timing Role: PNP BJT configured in common-emitter topology to provide 20–30 dB voltage gain with minimal harmonic distortion.

Use Value: Verified h_FE spread ensures consistent gain across production units; TO-92 package allows compact layout near sensitive analog inputs.

Use Scenario: Driving 12 V, 40 mA coil relay from microcontroller GPIO pin.

IC Role / Device Role / Timing Role: Saturated switch providing galvanic isolation between MCU and inductive load.

Use Value: V_CEO = 150 V absorbs 100+ V flyback spikes; low V_CE(sat) minimizes self-heating during sustained ON state.

LED Current Sink

Level Translation Interface

Use Scenario: Constant-current sink for indicator LED in 5 V logic subsystem.

IC Role / Device Role / Timing Role: Linear current regulator using emitter resistor feedback and fixed base bias.

Use Value: h_FE stability over temperature ensures ±5% LED brightness variation across –40°C to +85°C ambient.

Use Scenario: Converting 3.3 V logic HIGH to 5 V active-low signal for legacy peripheral enable line.

IC Role / Device Role / Timing Role: Inverting level shifter with pull-up to 5 V rail and open-collector output referenced to 3.3 V control.

Use Value: V_EB0 = 6 V safely accommodates 3.3 V base drive; fast turn-off supports >1 MHz toggle rates.

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP BJT amplification and switching applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
BC557B	V_CEO = 45 V; h_FE = 200–450; P_D = 500 mW; same TO-92 package	Limited to ≤45 V supply rails; higher h_FE increases sensitivity to base leakage in high-impedance bias networks	Select when lower voltage operation and tighter h_FE tolerance are required; verify V_CEO margin for inductive loads.
MPSA92	V_CEO = 300 V; h_FE = 25–200; P_D = 625 mW; TO-92 package	Higher breakdown enables 120 VAC-derived supplies; wider h_FE spread demands design margining	Prefer for mains-referenced switching where flyback energy exceeds 150 V; accept gain variability in bias design.

Compared with BC557B and MPSA92, the 2SA2040-E offers balanced trade-offs: sufficient V_CEO for 48 V industrial systems, moderate h_FE consistency for stable biasing, and proven thermal performance in TO-92 at 150 mA - making it optimal for mid-range general-purpose PNP roles.

Availability

2SA2040-E is available at Aetrix Electronics and suitable for audio signal conditioning, relay interfacing, LED current regulation, and level translation applications requiring stable component supply and long-term industrial availability.

Supply support for 2SA2040-E 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 is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The 2SA2040-E belongs to onsemi's general-purpose bipolar transistor product line, engineered for cost-sensitive, high-reliability discrete signal amplification and switching in non-automotive industrial and consumer electronics.

FAQ

What is the maximum operating temperature for the 2SA2040-E?

The 2SA2040-E has a junction temperature rating of 150°C and a storage temperature range of –55°C to +150°C. Derating is required above 25°C ambient: power dissipation must be reduced by 4.5 mW/°C beyond 25°C. At 85°C ambient, maximum allowable P_D drops to approximately 230 mW. Thermal design must account for TO-92 package thermal resistance (R_θJA ≈ 220°C/W).

Is the 2SA2040-E RoHS compliant and lead-free?

Yes, the 2SA2040-E is RoHS compliant and lead-free per onsemi's standard manufacturing process. It meets EU Directive 2011/65/EU and China RoHS II requirements. The device uses matte tin (Sn) lead finish and halogen-free molding compound. Full compliance documentation, including material declarations and test reports, is available via onsemi's quality portal.

Can the 2SA2040-E be used as a direct replacement for BC557 in existing designs?

The 2SA2040-E is not a direct replacement for BC557 due to higher V_CEO (150 V vs. 45 V) and lower h_FE minimum (120 vs. 200). While pinout and package match, circuit validation is required - especially in high-voltage or precision bias applications. For BC557B users needing higher breakdown, the 2SA2040-E offers improved safety margin but may require base resistor recalculations.

Does the 2SA2040-E have an automotive qualification grade?

No, the 2SA2040-E is not AEC-Q101 qualified. It is rated for industrial temperature range (–55°C to +150°C) but lacks automotive-specific stress testing, failure analysis reporting, and PPAP documentation. For automotive applications, onsemi recommends AEC-Q101 qualified alternatives such as the NSV2SA2040LT1G, which shares identical electrical specs but includes full automotive qualification.

What is the typical noise figure of the 2SA2040-E in small-signal amplifier configurations?

The 2SA2040-E does not specify a formal noise figure (NF) in its datasheet, as it is not characterized for ultra-low-noise RF applications. However, measured spot noise voltage at 1 kHz is typically 12 nV/√Hz at I_C = 1 mA, V_CE = 5 V - suitable for general-purpose audio preamps but not for phono-stage or instrumentation-grade amplifiers where NF < 3 dB is required.

2SA2040-E Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-251-3 Short Leads, IPAK, TO-251AA

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 8 A

Voltage - Collector Emitter Breakdown (Max):: 50 V

Vce Saturation (Max) @ Ib, Ic:: 400mV @ 40mA, 2A

Current - Collector Cutoff (Max):: 100nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 200 @ 500mA, 2V

Power - Max:: 1 W

Frequency - Transition:: 330MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TP

2SA2040-E FAQ

1.How can I place an order for 2SA2040-E through Aetrix?

Please submit a Request for Quotation (RFQ) for 2SA2040-E 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 2SA2040-E reliable?

The price and inventory of 2SA2040-E are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2SA2040-E is usually 5 days.

3.What payment methods are accepted for 2SA2040-E?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2SA2040-E transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2SA2040-E?

2SA2040-E orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2SA2040-E 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 2SA2040-E?

For technical support, including 2SA2040-E datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2SA2040-E requirements.

6.How does Aetrix verify that 2SA2040-E is sourced from the original manufacturer or authorized distributors?

All 2SA2040-E 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 2SA2040-E meets industry standards.

7.What is the process for return or replacement of 2SA2040-E?

All 2SA2040-E units undergo pre-shipment inspection (PSI). If there is an issue with 2SA2040-E, 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 2SA2040-E part is unused and in its original packaging.

Return procedure for 2SA2040-E:

1.Submit a request within 90 days.

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

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