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

onsemi MPSA27RLRA

Name: MPSA27RLRA
Brand: onsemi
SKU: MPSA27RLRA
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MPSA27RLRA

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: -

Datasheet:: MPSA27RLRA.pdf

Description:: TRANS NPN DARL SS 60V TO92

Quantity:: RFQ Add To RFQ list

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Inventory:6,270

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Product details

Overview

MPSA27RLRA from onsemi is an NPN silicon Darlington transistor in a TO-92 package, rated for 60 V_CE, 500 mA continuous collector current, and 625 mW power dissipation at 25°C. It delivers high DC current gain (h_FE ≥ 10,000 at I_C = 10 mA), low saturation voltage (V_CE(sat) ≤ 1.5 V at I_C = 100 mA/I_B = 0.1 mA), and is commonly used in low-speed switching and signal amplification circuits requiring high input impedance and current boosting.

For engineers reviewing the MPSA27RLRA datasheet, pinout, applications, or equivalent options, key selection considerations include its Darlington configuration, TO-92 mechanical compatibility, guaranteed minimum h_FE, V_CE(sat) under specified drive conditions, and thermal derating behavior above 25°C.

Technical Context

The MPSA27RLRA integrates two cascaded NPN transistors in a monolithic Darlington pair, providing high current gain with single-base control. Its structure enables high input impedance and low base drive requirements while maintaining discrete device reliability and thermal stability up to +150°C junction temperature.

It operates in linear and saturated modes, with verified V_BE(on) ≤ 2.0 V at I_C = 100 mA and V_CE = 5.0 V, and exhibits small-signal current gain (h_fe) of 1.25–2.4 at 100 MHz - confirming usable bandwidth beyond basic switching applications.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CE max	60 V - supports operation in 24 V and 48 V industrial control rails with margin.
I_C continuous	500 mA - suitable for driving relays, small solenoids, and LED arrays without external heat sinking.
h_FE min	10,000 at I_C = 10 mA - enables microamp-level base drive for robust switching in battery-powered systems.
V_CE(sat) max	1.5 V at I_C = 100 mA / I_B = 0.1 mA - ensures low conduction loss and minimal self-heating during sustained on-state operation.
R_θJA	200 °C/W - defines thermal performance in still-air PCB mounting; requires layout-aware copper area for >250 mA continuous use.
T_J range	−55°C to +150°C - qualified for automotive under-hood and industrial ambient environments.

Pinout & Package

Package: TO-92 (Case 29-11), straight-lead, Pb-free, tape-and-reel packaging (2000 units per reel).

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Emitter terminal of Darlington pair	Common reference node; connects to ground or low-side return path in switch configurations.
2 (Base)	Input control terminal	Drives both internal transistors; requires current limiting resistor to prevent overdrive and thermal runaway.
3 (Collector)	Output current terminal	Connects to load high-side; handles full switched current with V_CE drop governed by saturation characteristics.

Key Features

Feature	Design Value
High h_FE (≥10,000)	Reduces required base drive current by ~100× vs. single BJT, simplifying microcontroller GPIO interfacing.
Low V_CE(sat) (≤1.5 V)	Minimizes power loss in on-state, enabling efficient operation at 100–500 mA loads without forced air cooling.
TO-92 mechanical standardization	Enables drop-in replacement in legacy through-hole designs and compatibility with automated insertion equipment.
Pb-free construction	Meets RoHS Directive 2011/65/EU and JEDEC J-STD-020 reflow profile requirements.

Applications

Relay Driver Circuit	LED Array Switching
Use Scenario: Driving 12 V/24 V electromagnetic relays in PLC I/O modules and HVAC controllers. IC Role / Device Role / Timing Role: High-gain Darlington switch providing galvanic isolation between logic-level MCU outputs and relay coils. Use Value: Eliminates need for external driver stages; 10,000 h_FE allows direct GPIO control with <100 µA base current.	Use Scenario: Sequencing multi-segment LED displays in industrial status panels and instrumentation dashboards. IC Role / Device Role / Timing Role: Low-loss current sink for common-anode LED strings operating at 20–100 mA per segment. Use Value: V_CE(sat) ≤ 1.5 V preserves forward voltage headroom for red/green/yellow LEDs while minimizing thermal rise.
Linear Voltage Regulator Pass Element	Signal Amplifier Stage
Use Scenario: Medium-current pass transistor in adjustable 3-terminal linear regulators supplying 100–400 mA to analog sensor subsystems. IC Role / Device Role / Timing Role: Series-pass element controlled by error amplifier feedback loop; operates in active region. Use Value: High h_FE improves regulation accuracy by reducing base current error contribution to output current sensing.	Use Scenario: Pre-amplification of low-level sensor signals (e.g., thermistor bridges, photodiode currents) before ADC sampling. IC Role / Device Role / Timing Role: High-input-impedance common-emitter amplifier stage with DC-coupled bias network. Use Value: 2.4 h_fe at 100 MHz supports stable gain up to audio frequencies without oscillation risk in properly decoupled layouts.

Relay Driver Circuit

LED Array Switching

Use Scenario: Driving 12 V/24 V electromagnetic relays in PLC I/O modules and HVAC controllers.

IC Role / Device Role / Timing Role: High-gain Darlington switch providing galvanic isolation between logic-level MCU outputs and relay coils.

Use Value: Eliminates need for external driver stages; 10,000 h_FE allows direct GPIO control with <100 µA base current.

Use Scenario: Sequencing multi-segment LED displays in industrial status panels and instrumentation dashboards.

IC Role / Device Role / Timing Role: Low-loss current sink for common-anode LED strings operating at 20–100 mA per segment.

Use Value: V_CE(sat) ≤ 1.5 V preserves forward voltage headroom for red/green/yellow LEDs while minimizing thermal rise.

Linear Voltage Regulator Pass Element

Signal Amplifier Stage

Use Scenario: Medium-current pass transistor in adjustable 3-terminal linear regulators supplying 100–400 mA to analog sensor subsystems.

IC Role / Device Role / Timing Role: Series-pass element controlled by error amplifier feedback loop; operates in active region.

Use Value: High h_FE improves regulation accuracy by reducing base current error contribution to output current sensing.

Use Scenario: Pre-amplification of low-level sensor signals (e.g., thermistor bridges, photodiode currents) before ADC sampling.

IC Role / Device Role / Timing Role: High-input-impedance common-emitter amplifier stage with DC-coupled bias network.

Use Value: 2.4 h_fe at 100 MHz supports stable gain up to audio frequencies without oscillation risk in properly decoupled layouts.

Equivalent & Alternatives

The following parts are listed as comparable options for similar Darlington transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MPSA28RLRA	Higher V_CE rating (80 V vs. 60 V); identical TO-92 package and h_FE spec.	Better suited for 48 V telecom or PoE-powered systems where higher breakdown margin is required.	Select MPSA28RLRA when operating voltage exceeds 50 V or transient suppression headroom is critical.
ULN2003A	7-channel Darlington array IC (SO-16), integrated base resistors and clamp diodes; not discrete or pin-compatible.	Designed for parallel digital output driving (e.g., stepper motors, matrix displays); requires PCB redesign.	Choose ULN2003A only when multiple synchronized Darlington outputs are needed and board space permits SOIC footprint.

Compared with MPSA27RLRA, MPSA28RLRA offers higher voltage tolerance without sacrificing gain or package compatibility, while ULN2003A provides integration benefits at the cost of flexibility and discrete-level design control.

Availability

MPSA27RLRA is available at Aetrix Electronics and suitable for relay drivers, LED array switches, linear regulator pass elements, and low-frequency signal amplifiers requiring stable component supply across industrial control, test equipment, and embedded instrumentation programs.

Supply support for MPSA27RLRA 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 focused on energy-efficient innovation for automotive, industrial, cloud, and IoT applications.

The MPSA27RLRA belongs to onsemi's general-purpose bipolar transistor product line, engineered for cost-sensitive, high-reliability discrete switching and amplification in legacy and new-design through-hole systems.

FAQ

What is the maximum continuous collector current rating for MPSA27RLRA?

The MPSA27RLRA is rated for 500 mA continuous collector current at T_A = 25°C. Derating is required above this temperature - 5.0 mW/°C - meaning usable current drops to approximately 375 mA at 50°C ambient. This rating assumes adequate PCB copper area for heat dissipation and excludes second-breakdown limits shown in Figure 5 of the datasheet.

Does MPSA27RLRA have built-in protection features like flyback diodes?

No, the MPSA27RLRA is a bare Darlington transistor without integrated protection. External components - such as a reverse-biased diode across inductive loads - must be added to suppress voltage spikes during turn-off. This is standard practice for all discrete Darlington devices including MPSA27RLRA, and failure to implement clamping may cause premature device failure.

Is MPSA27RLRA pin-compatible with MPSA13 or MPSA14?

No, MPSA27RLRA is not pin-compatible with MPSA13 or MPSA14. While all three are TO-92 Darlington transistors, MPSA13/MPSA14 use emitter-base-collector (E-B-C) pinout order, whereas MPSA27RLRA uses emitter-base-collector (E-B-C) - same physical pin assignment - but differs in gain and saturation characteristics. However, electrical substitution requires verification of h_FE and V_CE(sat) in the target circuit; direct replacement is not guaranteed.

What is the typical base-emitter voltage for MPSA27RLRA under operating conditions?

The MPSA27RLRA exhibits a typical V_BE(on) of 2.0 V when operated at I_C = 100 mA and V_CE = 5.0 V. This reflects the stacked V_BE of two series-connected NPN junctions. Designers must account for this higher forward voltage when sizing base resistors to ensure sufficient drive current without exceeding I_B limits.

Can MPSA27RLRA be used in linear amplifier configurations?

Yes, MPSA27RLRA can operate in the active region for linear amplification, as confirmed by its specified h_fe (1.25–2.4) at 100 MHz and safe operating area curves in Figure 5. However, due to its Darlington structure, it has higher output capacitance and lower f_T than single BJTs - making it best suited for audio-frequency and DC-coupled low-bandwidth amplifiers rather than RF or high-speed applications.

MPSA27RLRA Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: *

Package/Case:: -

Packaging:: Cut Tape (CT)

Product Status:: Obsolete

Transistor Type:: -

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

Voltage - Collector Emitter Breakdown (Max):: -

Vce Saturation (Max) @ Ib, Ic:: -

Current - Collector Cutoff (Max):: -

DC Current Gain (hFE) (Min) @ Ic, Vce:: -

Power - Max:: -

Frequency - Transition:: -

Operating Temperature:: -

Grade:: -

Qualification:: -

Mounting Type:: -

Supplier Device Package:: -

MPSA27RLRA FAQ

1.How can I place an order for MPSA27RLRA through Aetrix?

Please submit a Request for Quotation (RFQ) for MPSA27RLRA 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 MPSA27RLRA reliable?

The price and inventory of MPSA27RLRA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MPSA27RLRA is usually 5 days.

3.What payment methods are accepted for MPSA27RLRA?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MPSA27RLRA transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MPSA27RLRA?

MPSA27RLRA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MPSA27RLRA 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 MPSA27RLRA?

For technical support, including MPSA27RLRA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MPSA27RLRA requirements.

6.How does Aetrix verify that MPSA27RLRA is sourced from the original manufacturer or authorized distributors?

All MPSA27RLRA 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 MPSA27RLRA meets industry standards.

7.What is the process for return or replacement of MPSA27RLRA?

All MPSA27RLRA units undergo pre-shipment inspection (PSI). If there is an issue with MPSA27RLRA, 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 MPSA27RLRA part is unused and in its original packaging.

Return procedure for MPSA27RLRA:

1.Submit a request within 90 days.

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

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