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

onsemi BSR13

Name: BSR13
Brand: onsemi
SKU: BSR13
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BSR13

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-236-3, SC-59, SOT-23-3

Datasheet:: BSR13.pdf

Description:: TRANS NPN 30V 0.5A SOT-23-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BSR13 from Fairchild Semiconductor is an NPN general-purpose bipolar junction transistor (BJT) in SOT-23 package, rated for 30 V V_CEO, 0.5 A continuous collector current, and DC current gain (h_FE) of 100 at I_C = 150 mA, used in low-power switching and amplification circuits such as signal buffering in consumer audio interfaces.

For engineers reviewing the BSR13 datasheet, pinout, applications, or equivalent options, key selection criteria include V_CEO rating, saturation voltage at defined I_C/I_B, thermal resistance (357 °C/W), h_FE variation across operating current, and SOT-23 footprint compatibility with space-constrained PCB layouts.

Technical Context

The BSR13 operates as a discrete NPN amplifier/switch with base-emitter and collector-base junctions optimized for general-purpose linear and saturated-mode operation. Its h_FE spans 35–300 across I_C = 0.1 mA to 500 mA, and V_CE(sat) is specified at 0.4 V (I_C = 150 mA, I_B = 15 mA), confirming suitability for low-voltage logic-level drive.

Thermal performance is defined for FR-4 PCB mounting (1.6" × 1.6" × 0.06"), with R_θJA = 357 °C/W and P_D = 350 mW at 25°C, derating 2.8 mW/°C above ambient - indicating design dependency on board-level copper area for sustained power handling.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	30 V - maximum allowable collector-emitter voltage before breakdown; sets upper rail limit in low-voltage switching stages.
I_C (continuous)	0.5 A - absolute max DC collector current; defines steady-state load drive capability without thermal runaway.
h_FE @ I_C=150 mA	100 - current gain under typical bias; determines required base drive current for target collector load.
V_CE(sat) @ I_C=150 mA	0.4 V - collector-emitter voltage in hard saturation; directly impacts conduction loss and output low-level voltage.
R_θJA	357 °C/W - junction-to-ambient thermal resistance on standard FR-4; dictates temperature rise per watt dissipated on reference board.
f_T	250 MHz - current-gain bandwidth product at I_C=20 mA; indicates usable frequency range for small-signal amplification.

Pinout & Package

SOT-23 plastic surface-mount package with 3-pin configuration, 1.90 mm × 1.30 mm footprint, 0.95 mm pin pitch, and marked "U7" on top surface. Mounting requires reflow-compatible solder profile per JEDEC J-STD-020.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	E	Current sink terminal; connects to ground or low-side return path in common-emitter configurations.
2 (Base)	B	Control input; requires current-limited drive (e.g., series resistor) to achieve specified h_FE and V_CE(sat).
3 (Collector)	C	Current source terminal; delivers switched or amplified output to load; polarity-sensitive in NPN topology.

Key Features

Feature	Design Value
NPN bipolar junction transistor	Discrete active device with predictable current-controlled gain, enabling analog amplification and digital switching in one component.
SOT-23 package	Standardized 3-pin footprint compatible with automated pick-and-place and reflow assembly; supports high-density layout.
V_CEO = 30 V, I_C = 0.5 A	Rated for 3.3 V/5 V logic interfacing and low-power relay/LED driver applications without external protection.
V_CE(sat) ≤ 0.4 V @ I_C = 150 mA	Minimizes power loss and self-heating during saturation, improving efficiency in battery-powered switching nodes.

Applications

Audio Signal Buffering	Low-Voltage Logic-Level Shifting
Use Scenario: Amplifying line-level audio signals between codec outputs and headphone drivers in portable media players. IC Role / Device Role / Timing Role: NPN BJT configured in common-emitter mode to provide voltage gain and impedance transformation. Use Value: h_FE ≥ 75 at I_C = 10 mA ensures stable small-signal amplification with minimal distortion at 1 kHz–20 kHz.	Use Scenario: Translating 1.8 V GPIO output to 3.3 V or 5 V logic levels for peripheral enable/disable control. IC Role / Device Role / Timing Role: Digital switch operating in saturation/cutoff to translate logic states with rail-to-rail output swing. Use Value: V_CE(sat) ≤ 0.4 V guarantees output low < 0.5 V at 3.3 V supply, meeting TTL/CMOS input threshold requirements.
LED Current Switching	Small-Signal RF Amplifier Stage
Use Scenario: Driving indicator LEDs in industrial HMI panels where microcontroller I/O pins lack sufficient current drive. IC Role / Device Role / Timing Role: Low-side switch controlling LED anode-to-V_CC current path via emitter-grounded configuration. Use Value: I_C = 0.5 A rating supports up to 20 mA per LED across multiple parallel strings without derating.	Use Scenario: First-stage RF preamplifier in 2.4 GHz ISM-band receiver front-ends with low-noise biasing. IC Role / Device Role / Timing Role: Small-signal amplifier biased for linear operation at 20 mA collector current. Use Value: f_T = 250 MHz enables stable gain up to ~100 MHz; V_BR_CEO = 30 V provides margin against RF peak voltages.

Audio Signal Buffering

Low-Voltage Logic-Level Shifting

Use Scenario: Amplifying line-level audio signals between codec outputs and headphone drivers in portable media players.

IC Role / Device Role / Timing Role: NPN BJT configured in common-emitter mode to provide voltage gain and impedance transformation.

Use Value: h_FE ≥ 75 at I_C = 10 mA ensures stable small-signal amplification with minimal distortion at 1 kHz–20 kHz.

Use Scenario: Translating 1.8 V GPIO output to 3.3 V or 5 V logic levels for peripheral enable/disable control.

IC Role / Device Role / Timing Role: Digital switch operating in saturation/cutoff to translate logic states with rail-to-rail output swing.

Use Value: V_CE(sat) ≤ 0.4 V guarantees output low < 0.5 V at 3.3 V supply, meeting TTL/CMOS input threshold requirements.

LED Current Switching

Small-Signal RF Amplifier Stage

Use Scenario: Driving indicator LEDs in industrial HMI panels where microcontroller I/O pins lack sufficient current drive.

IC Role / Device Role / Timing Role: Low-side switch controlling LED anode-to-V_CC current path via emitter-grounded configuration.

Use Value: I_C = 0.5 A rating supports up to 20 mA per LED across multiple parallel strings without derating.

Use Scenario: First-stage RF preamplifier in 2.4 GHz ISM-band receiver front-ends with low-noise biasing.

IC Role / Device Role / Timing Role: Small-signal amplifier biased for linear operation at 20 mA collector current.

Use Value: f_T = 250 MHz enables stable gain up to ~100 MHz; V_BR_CEO = 30 V provides margin against RF peak voltages.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN general-purpose amplifier applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MMBT3904	V_CEO = 40 V, h_FE min = 100 @ I_C = 10 mA, R_θJA = 357 °C/W (same package)	Higher V_CEO allows wider supply rail flexibility; slightly tighter h_FE binning improves predictability in gain-critical designs.	Select MMBT3904 when higher voltage margin or tighter DC gain consistency is required without changing layout.
BC847B	V_CEO = 45 V, h_FE = 200–450 @ I_C = 2 mA, different h_FE distribution vs. BSR13's 35–300 range	Higher gain at low currents suits low-base-drive applications; not optimized for 150 mA saturation like BSR13.	Choose BC847B for ultra-low I_B drive needs but verify V_CE(sat) at target I_C, as it is not characterized at 150 mA in its datasheet.

Compared with MMBT3904 and BC847B, the BSR13 offers a balanced trade-off of saturation performance at 150 mA, moderate voltage rating, and broad h_FE range - making it preferable for cost-sensitive, medium-current switching where precise gain matching is secondary to robust on-state behavior.

Availability

BSR13 is available at Aetrix Electronics and suitable for audio buffering, logic-level translation, LED driving, and small-signal amplification requiring stable component supply across industrial control, consumer electronics, and embedded sensor interface designs.

Supply support for BSR13 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

Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016.

The BSR13 belongs to Fairchild's general-purpose bipolar transistor family designed for cost-effective, reliable switching and amplification in non-automotive commercial and industrial applications.

FAQ

What is the maximum continuous collector current rating for the BSR13?

The BSR13 has a maximum continuous collector current (I_C) rating of 0.5 A at T_A = 25°C. This rating assumes proper PCB thermal relief; actual usable current decreases with rising ambient temperature due to the 2.8 mW/°C derating factor and 357 °C/W junction-to-ambient thermal resistance. For sustained 0.5 A operation, board-level copper area must be verified per Fairchild's thermal guidelines.

Does the BSR13 support operation at elevated temperatures?

Yes, the BSR13 supports operation from –55°C to +150°C junction temperature. However, electrical characteristics such as h_FE and V_CE(sat) shift with temperature - for example, h_FE typically increases with junction temperature while V_CE(sat) rises. Designers must consult the full datasheet's temperature coefficient curves and ensure thermal design keeps T_J ≤ 150°C under worst-case power dissipation.

What is the pin configuration of the BSR13 in the SOT-23 package?

The BSR13 uses standard SOT-23 pinout: Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector, with marking "U7" on the top surface. This matches JEDEC TO-236AB outline and is identical to MMBT3904 and BC847-series devices - enabling direct footprint reuse where electrical specs align.

How does the BSR13's DC current gain (h_FE) vary with collector current?

The BSR13's h_FE varies significantly with I_C: minimum 35 at I_C = 0.1 mA, 50 at 1.0 mA, 75 at 10 mA, 100 at 150 mA, 50 at 150 mA with V_CE = 1.0 V, and 30 at 500 mA. This wide spread means circuit gain must be designed with feedback or tolerance margins - especially critical in linear amplifiers where h_FE drift affects bias stability.

Is the BSR13 suitable for RF amplification applications?

The BSR13 has an f_T of 250 MHz at I_C = 20 mA, V_CE = 20 V, making it usable in VHF and lower UHF small-signal amplification (e.g., up to ~100 MHz with adequate gain margin). However, it lacks specified noise figure, S-parameters, or RF-specific packaging - so it is appropriate only for non-critical, low-gain RF stages where broadband response suffices and noise is not dominant.

BSR13 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-236-3, SC-59, SOT-23-3

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Transistor Type:: NPN

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

Voltage - Collector Emitter Breakdown (Max):: 30 V

Vce Saturation (Max) @ Ib, Ic:: 1.6V @ 50mA, 500mA

Current - Collector Cutoff (Max):: 30nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 100 @ 150mA, 10V

Power - Max:: 350 mW

Frequency - Transition:: 250MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

BSR13 FAQ

1.How can I place an order for BSR13 through Aetrix?

Please submit a Request for Quotation (RFQ) for BSR13 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 BSR13 reliable?

The price and inventory of BSR13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BSR13 is usually 5 days.

3.What payment methods are accepted for BSR13?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BSR13 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BSR13?

BSR13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BSR13 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 BSR13?

For technical support, including BSR13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BSR13 requirements.

6.How does Aetrix verify that BSR13 is sourced from the original manufacturer or authorized distributors?

All BSR13 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 BSR13 meets industry standards.

7.What is the process for return or replacement of BSR13?

All BSR13 units undergo pre-shipment inspection (PSI). If there is an issue with BSR13, 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 BSR13 part is unused and in its original packaging.

Return procedure for BSR13:

1.Submit a request within 90 days.

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

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