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

onsemi BSP52T1

Name: BSP52T1
Brand: onsemi
SKU: BSP52T1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BSP52T1

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: -

Datasheet:: BSP52T1.pdf

Description:: TRANS DARL NPN 1A 80V SOT223

Quantity:: RFQ Add To RFQ list

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Inventory:2,240

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Product details

Overview

BSP52T1 from onsemi is an NPN small-signal Darlington transistor in SOT-223 package, rated for 80 V V_CES, 1.0 A I_C, and 1.25 W P_D (on 1 cm² pad), designed for medium-power switching in relay, solenoid, lamp, and print hammer drivers.

For engineers reviewing the BSP52T1 datasheet, pinout, applications, or equivalent options, key selection factors include its Darlington gain (h_FE ≥ 1000 at 150 mA), low base drive requirement (V_BE(sat) = 1.9 V), and thermal performance (R_JA = 100 °C/W on optimized PCB).

Technical Context

This device implements a two-stage NPN Darlington configuration to achieve high DC current gain with minimal base drive current. It operates as a saturated switch, not a linear amplifier, with specified V_CE(sat) ≤ 1.3 V at I_C = 500 mA and I_B = 0.5 mA.

Its switching behavior is characterized by tr = 155 ns, td = 205 ns, ts = 420 ns, and tf = 365 ns under defined test conditions (V_CC = 10 V, I_C = 150 mA). The SOT-223 package supports surface-mount reflow or wave soldering with formed leads that absorb thermal stress.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CES	80 V - Maximum collector-emitter voltage before breakdown in common-emitter configuration
I_C	1.0 A - Continuous collector current rating at T_C = 25°C
h_FE	1000–2000 - DC current gain range at I_C = 150 mA, enabling low-base-drive switching
V_CE(sat)	≤1.3 V - Low saturation voltage at I_C = 500 mA / I_B = 0.5 mA, minimizing conduction loss
R_JA	100 °C/W - Junction-to-ambient thermal resistance on FR-4 with 1 cm² copper pad
f_T	~130 MHz - Current-gain-bandwidth product at I_C = 150 mA, V_CE = 2 V
V_BE(sat)	≤1.9 V - Base-emitter saturation voltage at I_C = 500 mA / I_B = 0.5 mA

Pinout & Package

The BSP52T1 is housed in a SOT-223 (Case 318E) surface-mount package with four terminals: Collector (pins 2 and 4), Base (pin 1), and Emitter (pin 3). The dual-collector configuration improves thermal and current-handling capability.

Pin/Terminal	Circuit Role	Design Meaning
1	Base	Input control terminal; drives internal Darlington pair with low current (I_B = 0.5 mA typical for 500 mA I_C)
2, 4	Collector	High-current output node; pins 2 and 4 are internally connected and share load current and thermal path
3	Emitter	Common emitter reference; connects to ground or return path in low-side switch configurations

Key Features

Feature	Design Value
Darlington architecture	Provides h_FE ≥ 1000, reducing required base drive current by ~10× vs. single NPN
SOT-223 thermal design	Enables 1.25 W power dissipation with 100 °C/W R_JA on standard 1 cm² PCB copper area
Pb-free, RoHS-compliant construction	Meets environmental compliance requirements without compromising solderability or reliability
AEC-Q101 qualification	Validated for automotive-grade temperature cycling, humidity, and mechanical stress per JESD22 standards

Applications

Relay Drivers	Lamp Drivers
Use Scenario: Driving 12 V/24 V electromagnetic relays in industrial PLC I/O modules. IC Role / Device Role / Timing Role: Low-side NPN Darlington switch controlling relay coil current up to 1 A. Use Value: High h_FE allows direct microcontroller GPIO drive without external base resistor network.	Use Scenario: Switching incandescent or LED indicator lamps in automotive dashboards. IC Role / Device Role / Timing Role: Medium-power saturated switch interfacing MCU outputs to lamp loads. Use Value: V_CE(sat) ≤ 1.3 V ensures >90% power efficiency at 500 mA load, minimizing heat buildup.
Solenoid Drivers	Print Hammer Actuators
Use Scenario: Controlling 24 V DC solenoids in vending machines and fluid control valves. IC Role / Device Role / Timing Role: High-current switching element handling inductive loads with flyback protection. Use Value: 80 V V_CES rating accommodates inductive kickback spikes without clamping diodes in many cases.	Use Scenario: Driving impact solenoids in dot-matrix printers requiring fast, repetitive actuation. IC Role / Device Role / Timing Role: Fast-switching Darlington transistor managing pulse-width modulated coil current. Use Value: ts = 420 ns and tf = 365 ns enable reliable operation at 1–2 kHz actuation frequencies.

Relay Drivers

Lamp Drivers

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

IC Role / Device Role / Timing Role: Low-side NPN Darlington switch controlling relay coil current up to 1 A.

Use Value: High h_FE allows direct microcontroller GPIO drive without external base resistor network.

Use Scenario: Switching incandescent or LED indicator lamps in automotive dashboards.

IC Role / Device Role / Timing Role: Medium-power saturated switch interfacing MCU outputs to lamp loads.

Use Value: V_CE(sat) ≤ 1.3 V ensures >90% power efficiency at 500 mA load, minimizing heat buildup.

Solenoid Drivers

Print Hammer Actuators

Use Scenario: Controlling 24 V DC solenoids in vending machines and fluid control valves.

IC Role / Device Role / Timing Role: High-current switching element handling inductive loads with flyback protection.

Use Value: 80 V V_CES rating accommodates inductive kickback spikes without clamping diodes in many cases.

Use Scenario: Driving impact solenoids in dot-matrix printers requiring fast, repetitive actuation.

IC Role / Device Role / Timing Role: Fast-switching Darlington transistor managing pulse-width modulated coil current.

Use Value: ts = 420 ns and tf = 365 ns enable reliable operation at 1–2 kHz actuation frequencies.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MMBD1402LT1G	Lower I_C (200 mA), smaller SOT-23 package, no dual-collector configuration	Not suitable for >300 mA loads; limited thermal capacity	Select when board space is constrained and load current ≤ 200 mA
BSP51T1G	PNP complement; same package, mirrored polarity, V_CEO = −80 V, I_C = −1.0 A	Used in high-side switching or complementary driver stages	Select only for PNP topology needs; not a functional replacement for BSP52T1

Compared with MMBD1402LT1G and BSP51T1G, the BSP52T1 offers higher current handling (1.0 A), superior thermal performance (1.25 W on 1 cm²), and dual-collector layout-making it uniquely suited for medium-power NPN switching where gain, saturation voltage, and robustness are jointly critical.

Availability

BSP52T1 is available at Aetrix Electronics and suitable for relay drivers, solenoid controls, lamp switching, and print hammer actuation requiring stable component supply across industrial automation, automotive body electronics, and embedded electromechanical systems.

Supply support for BSP52T1 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, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The BSP52T1 belongs to onsemi's medium-power discrete transistor family, engineered specifically for robust, high-gain switching in electromechanical interface applications where reliability under thermal and electrical stress is essential.

FAQ

What is the maximum continuous collector current for the BSP52T1?

The BSP52T1 is rated for a maximum continuous collector current of 1.0 A at case temperature T_C = 25°C. Derating applies above 25°C per the datasheet's 10 mW/°C slope for the 1.25 W power rating condition. Actual usable current depends on PCB copper area and ambient temperature; with 1 cm² pad, full 1.0 A is achievable below ~75°C ambient.

Does the BSP52T1 have a built-in base-emitter resistor?

No, the BSP52T1 does not include any integrated base-emitter resistor. It is a bare Darlington transistor requiring external base current limiting. This gives designers full control over switching speed and saturation depth but necessitates proper base resistor calculation based on target I_C and h_FE minimum.

Is the BSP52T1 suitable for automotive applications?

Yes, the BSP52T1 is AEC-Q101 qualified and PPAP capable, making it suitable for automotive applications such as body control modules, lighting drivers, and HVAC actuators. Its operating temperature range (−65°C to +150°C) and robust construction meet automotive reliability requirements.

What is the difference between BSP52T1G and BSP52T1?

The BSP52T1G designation indicates the Pb-free, RoHS-compliant version of the BSP52T1. Both share identical electrical specifications, pinout, and package. The "G" suffix reflects environmental compliance; the base part number BSP52T1 refers to the same device family and is used for ordering the 7-inch/1000-unit reel.

Can the BSP52T1 be used in linear amplification mode?

No, the BSP52T1 is explicitly designed and characterized for switching applications-not linear amplification. Its datasheet provides only saturation, cutoff, and switching parameters; no small-signal h_fe, f_T linearity, or distortion data is specified for analog use. Operating in active region risks thermal instability and undefined gain behavior.

BSP52T1 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:: -

BSP52T1 FAQ

1.How can I place an order for BSP52T1 through Aetrix?

Please submit a Request for Quotation (RFQ) for BSP52T1 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 BSP52T1 reliable?

The price and inventory of BSP52T1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BSP52T1 is usually 5 days.

3.What payment methods are accepted for BSP52T1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BSP52T1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BSP52T1?

BSP52T1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BSP52T1 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 BSP52T1?

For technical support, including BSP52T1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BSP52T1 requirements.

6.How does Aetrix verify that BSP52T1 is sourced from the original manufacturer or authorized distributors?

All BSP52T1 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 BSP52T1 meets industry standards.

7.What is the process for return or replacement of BSP52T1?

All BSP52T1 units undergo pre-shipment inspection (PSI). If there is an issue with BSP52T1, 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 BSP52T1 part is unused and in its original packaging.

Return procedure for BSP52T1:

1.Submit a request within 90 days.

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

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