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

Nexperia USA Inc. BST52,135

Name: BST52,135
Brand: Nexperia USA Inc.
SKU: BST52,135
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BST52,135

Manufacturer:: Nexperia USA Inc.

Category:: Single Bipolar Transistors

Package:: TO-243AA

Datasheet:: BST52,135.pdf

Description:: TRANS NPN DARL 80V 1A SOT-89

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BST52 from Nexperia is an AEC-Q101-qualified NPN Darlington transistor in SOT89 (SC-62) surface-mount package, delivering 1 A continuous collector current, 80 V V_CEO, DC current gain (h_FE) ≥1000 at 150 mA, and integrated base-emitter diode + resistor for simplified drive. It serves as a high-gain switching element in industrial solenoid, relay, and lamp driver circuits.

For engineers reviewing the BST52 datasheet, BST52 pinout, BST52 application, or BST52 equivalent, key selection criteria include its 1.3 W power dissipation at T_amb ≤25 °C, 1.3 V V_CEsat at I_C = 500 mA / I_B = 0.5 mA, AEC-Q101 qualification, and SOT89 thermal performance with R_th(j-sp) = 16 K/W.

Technical Context

The BST52 implements a monolithic NPN Darlington pair with integrated base-emitter clamping diode and series base resistor-reducing external component count in high-side load switching. Its architecture supports robust turn-on/turn-off control under pulsed conditions (t_p ≤ 300 µs, duty δ ≤ 0.02).

Designed for automotive-grade reliability, it meets AEC-Q101 stress test requirements and operates across −65 °C to +150 °C ambient and junction temperatures. Thermal design leverages the SOT89 collector pad (6 cm² copper area) to achieve R_th(j-a) = 96 K/W in free air and R_th(j-sp) = 16 K/W to solder point.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	80 V - Maximum safe collector-emitter voltage with open base; defines maximum load supply voltage in switching applications.
I_C	1 A continuous - Rated collector current enabling direct drive of 12 V/24 V solenoids, relays, and lamps without external heat sinking.
h_FE	≥1000 at I_C = 150 mA - High DC current gain reduces required base drive current, simplifying microcontroller GPIO interface.
V_CEsat	≤1.3 V at I_C = 500 mA / I_B = 0.5 mA - Low saturation voltage minimizes conduction loss and self-heating during sustained on-state operation.
R_th(j-sp)	16 K/W - Junction-to-solder-point thermal resistance enables predictable PCB-level thermal management using standard FR4 layout guidelines.
t_off	≤1500 ns - Turn-off time supports PWM frequencies up to ~100 kHz in medium-speed industrial switching applications.

Pinout & Package

SOT89 (SC-62) plastic surface-mount package: 3-lead, 1.5 mm pitch, 4.5 mm × 2.5 mm × 1.5 mm body; collector tab thermally and electrically connected to Pin 2.

Pin/Terminal	Circuit Role	Design Meaning
1	Emitter	Low-impedance output node; connects to ground or load return path; forms Darlington emitter output stage.
2	Collector	Main power output terminal; electrically and thermally tied to exposed metal tab for enhanced heat transfer to PCB copper.
3	Base	Control input with integrated series resistor; accepts logic-level drive (e.g., 3.3 V/5 V MCU GPIO) without external current-limiting resistor.

Key Features

Feature	Design Value
Integrated base resistor + emitter diode	Eliminates need for external bias components, reducing BOM count and PCB footprint in discrete switch designs.
AEC-Q101 qualification	Validated for automotive-grade temperature cycling, humidity, and mechanical stress-enabling use in under-hood industrial controls.
High h_FE (≥1000)	Enables single-stage Darlington switching with <1 mA base drive for 1 A loads, easing low-power MCU interfacing.
Low V_CEsat (≤1.3 V)	Reduces power dissipation to ≤1.3 W at full load, supporting compact thermal design without forced airflow.

Applications

Print Hammer Driver

Solenoid Control

Use Scenario: Driving electromagnetic print hammers in industrial dot-matrix printers requiring fast, high-current pulses.

IC Role / Device Role / Timing Role: High-gain NPN Darlington switch providing 1 A peak current with <1.3 V saturation drop and ≤1500 ns turn-off.

Use Value: Enables precise hammer actuation timing and low conduction loss over millions of cycles without thermal derating.

Use Scenario: Controlling 12 V/24 V linear solenoids in factory automation valves and pneumatic actuators.

IC Role / Device Role / Timing Role: Load switch handling inductive kickback via integrated clamp diode and sustaining 1 A steady-state current.

Use Value: Eliminates need for external flyback diode and base resistor, reducing component count and board space by ≥2 parts per channel.

Relay Coil Driver

Lamp Load Switch

Use Scenario: Energizing 12 V/24 V electromagnetic relay coils in PLC I/O modules and power distribution panels.

IC Role / Device Role / Timing Role: High-current, low-V_CEsat switch driving inductive relay loads with integrated base resistor for clean turn-on.

Use Value: Ensures reliable coil energization even with marginal MCU drive strength; suppresses base oscillation without added RC snubber.

Use Scenario: Switching incandescent or LED-based indicator lamps and panel lighting in automotive dashboards and industrial HMIs.

IC Role / Device Role / Timing Role: Robust DC load switch rated for 1 A continuous, supporting hot-plug and surge-tolerant lamp turn-on.

Use Value: Withstands lamp cold-resistance inrush (up to 10× steady-state current) due to 2 A I_CM peak rating and 150 °C T_j limit.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
ON Semiconductor NSS12500UW3T1G	Lower h_FE (min 250), higher V_CEsat (1.5 V), no integrated base resistor, SOT-323 package.	Requires external base resistor; less suitable for low-drive MCU interfaces; smaller thermal mass limits I_C to 0.5 A continuous.	Select when board space is critical and base drive capability exceeds 2 mA; not drop-in for BST52's integrated biasing.
Diodes Incorporated DXT7051Q-13	Higher V_CEO (100 V), same h_FE (1000 min), no integrated diode, SOT-89 package, AEC-Q101 qualified.	Lacks integrated emitter-base diode; requires external flyback protection for inductive loads; identical thermal mounting.	Prefer where higher voltage margin is needed and external clamping is acceptable; matches BST52's footprint and drive simplicity except for diode omission.

Compared with NSS12500UW3T1G and DXT7051Q-13, BST52 uniquely combines integrated base resistor + emitter diode, 1 A continuous rating in SOT89, and AEC-Q101 qualification-making it optimal for space-constrained, low-component-count industrial switching where drive simplicity and inductive load robustness are prioritized.

Availability

BST52 is available at Aetrix Electronics and suitable for industrial solenoid control, relay coil driving, and lamp load switching requiring stable component supply and automotive-grade reliability.

Supply support for BST52 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

Nexperia is a global semiconductor expert focused on high-volume, high-reliability essential semiconductors-including logic, discretes, MOSFETs, and ESD protection devices.

BST52 belongs to Nexperia's AEC-Q101-qualified bipolar transistor family, engineered specifically for robust, low-complexity industrial and automotive load switching where integration, thermal performance, and qualification matter.

FAQ

What is the maximum continuous collector current for BST52 at 25 °C ambient?

The BST52 is rated for 1 A continuous collector current (I_C) when mounted on an FR4 PCB with specified 6 cm² collector copper area and ambient temperature ≤25 °C. Derating applies above 25 °C per the R_th(j-a) = 96 K/W thermal resistance; at 70 °C ambient, max I_C drops to approximately 0.7 A to maintain T_j ≤150 °C.

Does BST52 require an external base resistor when driven by a 3.3 V microcontroller GPIO?

No. The BST52 integrates a base resistor optimized for direct logic-level drive; at 3.3 V, it delivers ~0.5 mA base current-sufficient to saturate the Darlington at up to 500 mA collector current. External resistor addition is unnecessary and may impair switching speed or saturation depth.

Can BST52 replace a standard NPN transistor like BC817 in relay driver circuits?

Yes-with caveats. BST52 offers higher h_FE (≥1000 vs. ~250), lower V_CEsat (≤1.3 V vs. ~0.7 V), and integrated base resistor/diode, but has slower turn-off (1500 ns vs. ~200 ns). It excels in high-current, low-speed switching where gain and integration outweigh speed; not recommended for >50 kHz PWM.

Is the SOT89 package of BST52 compatible with standard reflow soldering profiles?

Yes. Nexperia specifies compatibility with JEDEC J-STD-020D reflow profiles. The SOT89 footprint (Fig. 4) uses 1.2 mm × 1.9 mm solder lands per lead and supports peak temperatures up to 260 °C. Critical for thermal performance: ensure ≥6 cm² of 1 oz. copper connected to Pin 2 (collector) for optimal heat dissipation.

BST52,135 Specifications

Product attributes: Attribute value

Manufacturer:: Nexperia USA Inc.

Series:: -

Package/Case:: TO-243AA

Packaging:: Tape & Reel (TR)

Product Status:: Active

Transistor Type:: NPN - Darlington

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

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

Vce Saturation (Max) @ Ib, Ic:: 1.3V @ 500µA, 500mA

Current - Collector Cutoff (Max):: 500nA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 2000 @ 500mA, 10V

Power - Max:: 1.3 W

Frequency - Transition:: 200MHz

Operating Temperature:: 150°C (TJ)

Grade:: Automotive

Qualification:: AEC-Q101

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-89

BST52,135 FAQ

1.How can I place an order for BST52,135 through Aetrix?

Please submit a Request for Quotation (RFQ) for BST52,135 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 BST52,135 reliable?

The price and inventory of BST52,135 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BST52,135 is usually 5 days.

3.What payment methods are accepted for BST52,135?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BST52,135 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BST52,135?

BST52,135 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BST52,135 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 BST52,135?

For technical support, including BST52,135 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BST52,135 requirements.

6.How does Aetrix verify that BST52,135 is sourced from the original manufacturer or authorized distributors?

All BST52,135 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 BST52,135 meets industry standards.

7.What is the process for return or replacement of BST52,135?

All BST52,135 units undergo pre-shipment inspection (PSI). If there is an issue with BST52,135, 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 BST52,135 part is unused and in its original packaging.

Return procedure for BST52,135:

1.Submit a request within 90 days.

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

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