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

onsemi MPSA43

Name: MPSA43
Brand: onsemi
SKU: MPSA43
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MPSA43

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: MPSA43.pdf

Description:: TRANS NPN 200V 0.5A TO92

Quantity:: RFQ Add To RFQ list

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Inventory:3,390

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Product details

Overview

MPSA43 from ON Semiconductor (formerly Fairchild) is an NPN bipolar junction transistor designed for high-voltage amplification and switching in video output stages, CRT deflection circuits, and other 200 V-rated applications. It features V_CEO = 200 V, I_C = 200 mA continuous, h_FE = 25–200 (at I_C = 1–30 mA), f_T = 50 MHz, and TO-92 package.

For engineers reviewing the MPSA43 datasheet, pinout, applications, or equivalent options, key selection considerations include high-voltage breakdown margin, DC current gain linearity across operating current, saturation voltage at driver-level base currents, thermal resistance in through-hole layouts, and compatibility with legacy video amplifier reference designs.

Technical Context

The MPSA43 operates as a general-purpose NPN amplifier with high collector-emitter and collector-base breakdown ratings (200 V each), enabling use in flyback, horizontal deflection, and HV bias supply circuits where transient overvoltage immunity is critical. Its f_T of 50 MHz supports stable small-signal amplification up to video bandwidths without oscillation under proper layout.

Designed for linear operation in Class-A or Class-AB video output stages, it delivers predictable h_FE variation (25–200) across 1–30 mA collector current and maintains low C_cb = 4.0 pF at 20 V reverse bias - minimizing Miller effect in high-gain configurations.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	200 V - Supports operation in CRT anode drive, HV power supply feedback, and pulse transformer primary switching without breakdown.
I_C (cont.)	200 mA - Sufficient for driving moderate-current video output loads and relay coils in industrial control interfaces.
h_FE	25–200 - Enables stable DC biasing across production lots and temperature; usable in emitter-follower and common-emitter topologies.
V_CE(sat)	0.4 V @ I_C=20 mA, I_B=2 mA - Ensures low conduction loss when used as a saturated switch in HV logic interface circuits.
f_T	50 MHz - Permits faithful amplification of composite video signals (up to ~5 MHz) with adequate gain margin and phase stability.
R_θJA	200 °C/W - Requires PCB copper pour or spacing from heat sources in enclosed enclosures to maintain T_J ≤ 150 °C at full power.

Pinout & Package

Package: TO-92 - Standard through-hole plastic package with 1.27 mm lead pitch, 3.60 mm body width, and 14.47 mm overall length; suitable for wave soldering and manual prototyping.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current sink terminal	Connected to ground or low-impedance return path; polarity defines NPN operation and current direction in amplifier/switch topologies.
2 (Base)	Control input	Receives forward-biased current to modulate collector current; requires current-limiting resistor in most driver applications.
3 (Collector)	High-voltage output node	Handles up to 200 V swing; connected to load (e.g., CRT grid, HV transformer primary) and decoupling capacitor in video output stages.

Key Features

Feature	Design Value
High V_CEO/V_CBO	200 V rating enables direct replacement of older high-voltage transistors in legacy CRT and HV power supply designs.
Low V_CE(sat)	0.4 V saturation ensures minimal power dissipation when used as a grounded-emitter switch driving inductive or capacitive HV loads.
Stable h_FE range	25–200 across 1–30 mA allows consistent bias design without binning; supports both low-current sensing and medium-power drive.
Low C_cb	4.0 pF at 20 V reduces Miller capacitance, improving high-frequency response and stability in wideband amplifier configurations.

Applications

Video Output Stage	Horizontal Deflection Circuit
Use Scenario: Amplifying composite video signal to drive CRT cathode or grid with 100–200 V peak-to-peak swing. IC Role / Device Role / Timing Role: NPN amplifier in common-emitter configuration with active load or transformer coupling. Use Value: 200 V V_CEO prevents breakdown during sync pulse transients; 50 MHz f_T preserves luminance bandwidth fidelity.	Use Scenario: Switching flyback transformer primary in CRT horizontal deflection yoke drivers. IC Role / Device Role / Timing Role: High-voltage saturated switch turning on/off 15–20 kHz sawtooth current waveform. Use Value: 200 V V_CBO withstands flyback voltage spikes; 0.4 V V_CE(sat) limits conduction loss during 20% duty cycle operation.
HV Power Supply Feedback	Industrial Relay Driver
Use Scenario: Isolating and amplifying error signal from optocoupler in >100 V SMPS feedback loop. IC Role / Device Role / Timing Role: Linear amplifier translating isolated photocurrent into precise base drive for regulation transistor. Use Value: Stable h_FE across temperature ensures consistent loop gain; 200 °C/W R_θJA permits operation on small PCB areas with no heatsink.	Use Scenario: Driving 12–24 V coil of industrial control relays requiring ≥150 mA peak current. IC Role / Device Role / Timing Role: Medium-current saturated switch interfacing microcontroller GPIO to inductive load. Use Value: 200 mA I_C rating handles relay inrush; TO-92 mechanical robustness supports vibration-prone factory environments.

Video Output Stage

Horizontal Deflection Circuit

Use Scenario: Amplifying composite video signal to drive CRT cathode or grid with 100–200 V peak-to-peak swing.

IC Role / Device Role / Timing Role: NPN amplifier in common-emitter configuration with active load or transformer coupling.

Use Value: 200 V V_CEO prevents breakdown during sync pulse transients; 50 MHz f_T preserves luminance bandwidth fidelity.

Use Scenario: Switching flyback transformer primary in CRT horizontal deflection yoke drivers.

IC Role / Device Role / Timing Role: High-voltage saturated switch turning on/off 15–20 kHz sawtooth current waveform.

Use Value: 200 V V_CBO withstands flyback voltage spikes; 0.4 V V_CE(sat) limits conduction loss during 20% duty cycle operation.

HV Power Supply Feedback

Industrial Relay Driver

Use Scenario: Isolating and amplifying error signal from optocoupler in >100 V SMPS feedback loop.

IC Role / Device Role / Timing Role: Linear amplifier translating isolated photocurrent into precise base drive for regulation transistor.

Use Value: Stable h_FE across temperature ensures consistent loop gain; 200 °C/W R_θJA permits operation on small PCB areas with no heatsink.

Use Scenario: Driving 12–24 V coil of industrial control relays requiring ≥150 mA peak current.

IC Role / Device Role / Timing Role: Medium-current saturated switch interfacing microcontroller GPIO to inductive load.

Use Value: 200 mA I_C rating handles relay inrush; TO-92 mechanical robustness supports vibration-prone factory environments.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN high-voltage amplifier applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MPSA42	V_CEO = 300 V, h_FE = 25–200, same TO-92 package and pinout	Higher breakdown margin for >250 V flyback or arc detection circuits; otherwise functionally interchangeable	Select MPSA42 when operating voltage exceeds 200 V but layout and drive conditions match MPSA43.
BC639	V_CEO = 80 V, I_C = 1 A, h_FE = 40–250, TO-92	Lower voltage rating but higher current capability; unsuitable for >100 V applications	Choose BC639 only for low-voltage, high-current switching where 200 V rating is unnecessary.

Compared with MPSA43, MPSA42 offers enhanced voltage headroom without layout change, while BC639 trades breakdown safety for current capacity - making MPSA43 the optimal balance for 150–200 V video and deflection circuits requiring proven reliability and thermal stability.

Availability

MPSA43 is available at Aetrix Electronics and suitable for video output stages, horizontal deflection circuits, HV power supply feedback loops, and industrial relay drivers requiring stable component supply and long-term obsolescence management.

Supply support for MPSA43 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 is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The MPSA43 belongs to ON Semiconductor's legacy bipolar transistor product line, originally developed by Fairchild for high-reliability analog video and HV switching applications where ruggedness and parameter consistency are critical.

FAQ

What is the maximum collector-emitter voltage rating for the MPSA43?

The MPSA43 has a guaranteed V_CEO rating of 200 V at T_A = 25°C, verified per JEDEC test conditions (I_C = 1.0 mA, I_B = 0). This rating applies to continuous DC and pulsed operation within thermal limits. Exceeding 200 V risks irreversible junction breakdown. The MPSA43 datasheet specifies this value in both Absolute Maximum Ratings and On Characteristics tables.

Does the MPSA43 have a documented pinout configuration, and what is it?

Yes, the MPSA43 has a standardized TO-92 pinout: Pin 1 is Emitter, Pin 2 is Base, Pin 3 is Collector - confirmed in the official ON Semiconductor datasheet Rev. B (November 2002) and consistent across all authorized distribution documentation. This pinout matches industry-standard NPN TO-92 devices including MPSA42 and 2N3904, enabling direct board-level substitution where voltage ratings align.

What is the typical DC current gain (h_FE) range for the MPSA43 across operating conditions?

The MPSA43 exhibits h_FE = 25 (min) to 200 (max) depending on collector current: 25–100 at I_C = 1.0 mA, 40–150 at I_C = 10 mA, and 50–200 at I_C = 30 mA, all measured at V_CE = 10 V and T_A = 25°C. This graded gain behavior is explicitly tabulated in the Electrical Characteristics section of the MPSA43 datasheet and supports predictable bias design across multiple operating points.

Can the MPSA43 be used as a saturated switch, and what is its saturation voltage?

Yes, the MPSA43 is qualified for saturated switching operation. Its V_CE(sat) is specified at 0.4 V maximum when I_C = 20 mA and I_B = 2.0 mA - a condition that ensures forced β = 10, confirming reliable saturation. This value is measured under pulse test conditions (≤300 µs, ≤2% duty cycle) and remains valid for repetitive switching up to 200 mA with appropriate thermal derating per the R_θJA = 200 °C/W specification.

Is the MPSA43 suitable for high-frequency video signal amplification?

Yes, the MPSA43 supports video-frequency amplification with a current-gain bandwidth product (f_T) of 50 MHz at I_C = 10 mA, V_CE = 20 V, and f = 100 MHz. Its 4.0 pF collector-base capacitance (C_cb) at 20 V further minimizes Miller effect, enabling stable small-signal gain up to 5–10 MHz - sufficient for NTSC/PAL composite video and monochrome monitor applications as stated in the device's original application description.

MPSA43 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:: NPN

Current - Collector (Ic) (Max):: 500 mA

Voltage - Collector Emitter Breakdown (Max):: 200 V

Vce Saturation (Max) @ Ib, Ic:: 500mV @ 2mA, 20mA

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

DC Current Gain (hFE) (Min) @ Ic, Vce:: 25 @ 1mA, 10V

Power - Max:: 625 mW

Frequency - Transition:: 50MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

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

MPSA43 FAQ

1.How can I place an order for MPSA43 through Aetrix?

Please submit a Request for Quotation (RFQ) for MPSA43 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 MPSA43 reliable?

The price and inventory of MPSA43 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MPSA43 is usually 5 days.

3.What payment methods are accepted for MPSA43?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MPSA43 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MPSA43?

MPSA43 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MPSA43 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 MPSA43?

For technical support, including MPSA43 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MPSA43 requirements.

6.How does Aetrix verify that MPSA43 is sourced from the original manufacturer or authorized distributors?

All MPSA43 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 MPSA43 meets industry standards.

7.What is the process for return or replacement of MPSA43?

All MPSA43 units undergo pre-shipment inspection (PSI). If there is an issue with MPSA43, 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 MPSA43 part is unused and in its original packaging.

Return procedure for MPSA43:

1.Submit a request within 90 days.

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

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