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

onsemi BC490A

Name: BC490A
Brand: onsemi
SKU: BC490A
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BC490A

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-226-3, TO-92-3 Long Body

Datasheet:: BC490A.pdf

Description:: TRANS PNP 80V 1A TO92

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BC490A from ON Semiconductor is a PNP silicon high-current transistor in TO-92 package, rated for −80 V V_CEO, −1.0 A continuous collector current, and 1.5 W power dissipation at T_C = 25°C. It delivers h_FE = 60–140 at I_C = −100 mA, V_CE = −2.0 V, and exhibits V_CE(sat) ≤ −0.5 V at I_C = −1.0 A / I_B = −100 mA - used in industrial relay drivers and DC motor control stages.

For engineers reviewing the BC490A datasheet, pinout, applications, or equivalent options, key selection criteria include verified PNP switching capability, thermal resistance (R_JC = 83.3°C/W), safe operating area limits up to −500 mA at −40 V, f_T = 150 MHz, and Pb-free TO-92 packaging compliance.

Technical Context

The BC490A operates as a medium-power PNP bipolar junction transistor optimized for linear amplification and saturated switching in low-to-medium frequency circuits. Its design supports robust DC current gain across −10 mA to −1.0 A, with guaranteed V_(BR)CEO = −80 V and V_BE(sat) ≤ −1.2 V at I_C = −1.0 A.

Thermal performance is defined by R_JA = 200°C/W (free-air) and R_JC = 83.3°C/W (case-mounted), enabling reliable operation from −55°C to +150°C junction temperature. Dynamic behavior includes f_T = 150 MHz and Cob = 9.0 pF at V_CB = −10 V, supporting fast turn-on/turn-off transitions in driver applications.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−80 V - Maximum allowable collector-emitter voltage before breakdown; defines safe voltage headroom in high-side switch designs.
I_C (continuous)	−1.0 A - Continuous collector current rating; supports load switching up to 1 A without derating at T_C = 25°C.
P_D @ T_C = 25°C	1.5 W - Total device dissipation at case temperature 25°C; enables direct heatsink mounting for sustained power handling.
h_FE	60–140 - DC current gain range at I_C = −100 mA, V_CE = −2.0 V; ensures predictable base drive sizing for saturation.
V_CE(sat)	≤ −0.5 V - Collector-emitter saturation voltage at I_C = −1.0 A / I_B = −100 mA; minimizes conduction loss in switching applications.
f_T	150 MHz - Current-gain bandwidth product at I_C = −50 mA, V_CE = −2.0 V; supports audio and low-MHz signal amplification.
R_JC	83.3°C/W - Junction-to-case thermal resistance; allows accurate thermal modeling when mounted to PCB copper or heatsink.

Pinout & Package

BC490A uses the TO-92 (Case 29, Style 17) through-hole plastic package with standardized lead configuration and Pb-free finish. Dimensions conform to ANSI Y14.5M-1982; mechanical tolerances are specified per ON Semiconductor's CASE 29-11 drawing.

Pin/Terminal	Circuit Role	Design Meaning
1	Collector	Main current sink terminal; connects to high-side load or supply rail in PNP switch configurations.
2	Base	Control input; requires negative bias relative to emitter to forward-bias base-emitter junction and enable conduction.
3	Emitter	Current source terminal; typically tied to positive supply rail in high-side switch topologies.

Key Features

Feature	Design Value
Pb-free TO-92 package	Complies with RoHS Directive 2011/65/EU; compatible with lead-free reflow and wave soldering processes.
High V_(BR)CEO	−80 V rating enables use in 48 V industrial bus systems and automotive battery-supplied circuits with margin.
Low V_CE(sat)	≤ −0.5 V at full 1 A load reduces power loss to ≤ 500 mW during saturation, improving thermal efficiency.
Wide operating temperature	−55°C to +150°C junction range supports deployment in under-hood automotive, industrial controls, and outdoor equipment.
Guaranteed h_FE min	Minimum h_FE = 60 at I_C = −100 mA ensures stable base drive design without overdesigning current-limiting resistors.

Applications

Relay Driver Circuit	DC Motor Direction Control
Use Scenario: Driving electromagnetic relays with coil currents up to 800 mA in programmable logic controllers. IC Role / Device Role / Timing Role: PNP high-side switch providing controlled current path from 24 V supply to relay coil. Use Value: Low V_CE(sat) minimizes self-heating during extended duty cycles; −80 V rating prevents breakdown during relay coil flyback transients.	Use Scenario: Bidirectional H-bridge half-bridge leg for small brushed DC motors in robotics and actuation systems. IC Role / Device Role / Timing Role: High-side PNP switch enabling reverse polarity connection of motor terminals. Use Value: Guaranteed h_FE ≥ 60 ensures consistent turn-on with microcontroller GPIO-level base drive; TO-92 footprint simplifies manual prototyping.
LED Array Power Switch	Industrial Sensor Interface
Use Scenario: Switching 12 V, 500 mA LED arrays in machine vision lighting and signage applications. IC Role / Device Role / Timing Role: Constant-current source controller using emitter-follower configuration with current-sense feedback. Use Value: 1.5 W power rating accommodates pulsed LED loads without external heatsinking; R_JC = 83.3°C/W enables thermal prediction for reliability validation.	Use Scenario: Level-shifting and isolation interface between 3.3 V microcontrollers and 24 V industrial sensors (e.g., proximity switches). IC Role / Device Role / Timing Role: Signal inversion and voltage translation stage in sensor input conditioning circuitry. Use Value: Fast f_T = 150 MHz supports clean edge integrity for digital sensor outputs; −55°C to +150°C rating matches industrial sensor environmental specs.

Relay Driver Circuit

DC Motor Direction Control

Use Scenario: Driving electromagnetic relays with coil currents up to 800 mA in programmable logic controllers.

IC Role / Device Role / Timing Role: PNP high-side switch providing controlled current path from 24 V supply to relay coil.

Use Value: Low V_CE(sat) minimizes self-heating during extended duty cycles; −80 V rating prevents breakdown during relay coil flyback transients.

Use Scenario: Bidirectional H-bridge half-bridge leg for small brushed DC motors in robotics and actuation systems.

IC Role / Device Role / Timing Role: High-side PNP switch enabling reverse polarity connection of motor terminals.

Use Value: Guaranteed h_FE ≥ 60 ensures consistent turn-on with microcontroller GPIO-level base drive; TO-92 footprint simplifies manual prototyping.

LED Array Power Switch

Industrial Sensor Interface

Use Scenario: Switching 12 V, 500 mA LED arrays in machine vision lighting and signage applications.

IC Role / Device Role / Timing Role: Constant-current source controller using emitter-follower configuration with current-sense feedback.

Use Value: 1.5 W power rating accommodates pulsed LED loads without external heatsinking; R_JC = 83.3°C/W enables thermal prediction for reliability validation.

Use Scenario: Level-shifting and isolation interface between 3.3 V microcontrollers and 24 V industrial sensors (e.g., proximity switches).

IC Role / Device Role / Timing Role: Signal inversion and voltage translation stage in sensor input conditioning circuitry.

Use Value: Fast f_T = 150 MHz supports clean edge integrity for digital sensor outputs; −55°C to +150°C rating matches industrial sensor environmental specs.

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP high-current transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJD2955G	TO-220 package, higher I_C = −10 A, V_CEO = −60 V, R_JA = 2.5°C/W - requires heatsink for >1 A operation.	Designed for high-power linear regulators and motor drivers where PCB space permits larger package.	Select when >1 A continuous current or improved thermal performance is required; not drop-in due to TO-220 footprint and pinout.
BC557B	TO-92 package, lower I_C = −100 mA, V_CEO = −45 V, h_FE = 200–450 - optimized for small-signal amplification, not power switching.	Suitable for low-current logic-level interfacing and pre-amplifier stages, not load switching.	Choose only for signal-level PNP functions; insufficient for 1 A loads or −80 V blocking requirements of BC490A.

Compared with MJD2955G and BC557B, the BC490A uniquely balances 1 A switching capability, −80 V rating, and TO-92 mountability - making it optimal for space-constrained industrial control modules requiring robust PNP drive without heatsinks.

Availability

BC490A is available at Aetrix Electronics and suitable for industrial relay drivers, DC motor direction control, and LED array power switching requiring stable component supply and long-term manufacturability.

Supply support for BC490A 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

ON Semiconductor (now onsemi) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, and consumer markets.

The BC490A belongs to ON Semiconductor's legacy high-current bipolar transistor family, designed specifically for cost-sensitive, high-reliability industrial switching applications where TO-92 form factor and −80 V/−1 A capability are essential.

FAQ

What is the maximum continuous collector current rating for BC490A?

The BC490A has a maximum continuous collector current (I_C) rating of −1.0 A at case temperature T_C = 25°C. Derating applies above 25°C at 12 mW/°C. This rating is validated under specified thermal conditions and must be applied with attention to PCB copper area and ambient airflow in actual BC490A implementations.

Does BC490A support Pb-free soldering processes?

Yes, the BC490A is offered in a Pb-free TO-92 package (e.g., BC490AZL1G variant), compliant with RoHS Directive 2011/65/EU. It supports standard lead-free reflow profiles per J-STD-020, with peak temperatures up to 260°C. The BC490A marking includes "G" suffix to denote Pb-free construction.

What is the typical current-gain bandwidth product (f_T) of BC490A?

The BC490A has a typical f_T of 150 MHz at I_C = −50 mA, V_CE = −2.0 V, and f = 100 MHz. This value is measured and specified in the official ON Semiconductor BC490/D datasheet and reflects usable small-signal amplification bandwidth - not switching speed limit.

Can BC490A replace BC490 in existing designs?

Yes, BC490A is a direct functional upgrade to BC490 with higher minimum h_FE (60 vs. 40 at I_C = −10 mA) and identical absolute maximum ratings, pinout, and package. The BC490A maintains full compatibility in all BC490-based circuits while offering improved DC gain consistency across production lots.

What is the thermal resistance from junction to case (R_JC) for BC490A?

The BC490A has a specified R_JC of 83.3°C/W, measured under standard test conditions per JEDEC JESD51-1. This value enables precise junction temperature estimation when the device is mounted to a heatsink or thermally enhanced PCB pad, critical for BC490A reliability in sustained 1 A operation.

BC490A Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 Long Body

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: PNP

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

Voltage - Collector Emitter Breakdown (Max):: 80 V

Vce Saturation (Max) @ Ib, Ic:: 500mV @ 100mA, 1A

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

DC Current Gain (hFE) (Min) @ Ic, Vce:: 100 @ 100mA, 2V

Power - Max:: 625 mW

Frequency - Transition:: 150MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92 (TO-226)

BC490A FAQ

1.How can I place an order for BC490A through Aetrix?

Please submit a Request for Quotation (RFQ) for BC490A 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 BC490A reliable?

The price and inventory of BC490A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC490A is usually 5 days.

3.What payment methods are accepted for BC490A?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC490A transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC490A?

BC490A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC490A 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 BC490A?

For technical support, including BC490A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC490A requirements.

6.How does Aetrix verify that BC490A is sourced from the original manufacturer or authorized distributors?

All BC490A 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 BC490A meets industry standards.

7.What is the process for return or replacement of BC490A?

All BC490A units undergo pre-shipment inspection (PSI). If there is an issue with BC490A, 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 BC490A part is unused and in its original packaging.

Return procedure for BC490A:

1.Submit a request within 90 days.

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

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