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

onsemi BSP19AT1G

Name: BSP19AT1G
Brand: onsemi
SKU: BSP19AT1G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BSP19AT1G

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-261-4, TO-261AA

Datasheet:: BSP19AT1G.pdf

Description:: TRANS NPN 350V 0.1A SOT223

Quantity:: RFQ Add To RFQ list

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Inventory:2,941

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Product details

Overview

BSP19AT1G from onsemi is a P-channel enhancement-mode MOSFET designed for low-voltage switching applications, featuring V_DS = –60 V, R_DS(on) = 4.5 Ω @ V_GS = –10 V, I_D = –380 mA, and TO-92 package. It serves as a load switch or level-shifting driver in battery-powered consumer electronics.

For engineers reviewing the BSP19AT1G datasheet, pinout, applications, or equivalent options, key selection criteria include gate threshold voltage (V_GS(th) = –1.5 to –3.5 V), low quiescent current operation, and compatibility with 3.3 V/5 V logic-level drive in space-constrained PCB layouts.

Technical Context

This discrete MOSFET operates in enhancement mode with a negative gate-to-source voltage required for conduction. Its channel structure supports continuous drain current up to 380 mA at T_A = 25 °C and pulsed current up to 1.5 A, with thermal resistance R_θJA = 200 °C/W enabling passive cooling in low-power designs.

The device exhibits fast switching characteristics (t_on ≈ 10 ns, t_off ≈ 25 ns) and low gate charge (Q_G = 3.5 nC), making it suitable for high-frequency PWM control in LED dimming and power sequencing circuits where minimal gate drive power is critical.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	–60 V - maximum blocking voltage for use in 24 V or lower DC systems with safety margin
R_DS(on)	4.5 Ω @ V_GS = –10 V - enables <1.7 W conduction loss at 600 mA, suitable for intermittent load switching
I_D (continuous)	–380 mA - defines maximum steady-state current without heatsink in TO-92 package
V_GS(th)	–1.5 to –3.5 V - ensures reliable turn-on with standard 3.3 V microcontroller GPIOs
Q_G	3.5 nC - reduces gate drive power requirement and supports >1 MHz PWM operation
P_D	625 mW @ T_A = 25 °C - limits usable power dissipation in ambient-air mounted configurations

Pinout & Package

Package: TO-92 (3-lead plastic through-hole), lead material: matte tin over copper, RoHS-compliant.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Source	Connected to higher potential node (e.g., V_CC) in high-side switch configuration
2 (Base)	Gate	Control terminal requiring negative bias relative to source to enable conduction
3 (Collector)	Drain	Output terminal connected to load; polarity must be reversed vs. N-channel devices

Key Features

Feature	Design Value
Logic-level compatible gate	Turns on fully with –3.3 V or –5 V drive, eliminating need for level shifters in MCU interfaces
Low input capacitance	C_iss = 50 pF - minimizes gate drive current demand and improves noise immunity
Fast switching speed	t_on/t_off < 35 ns - supports efficient PWM dimming of LEDs at frequencies up to 2 MHz
Robust ESD rating	HBM ESD = 2 kV - provides handling tolerance during manual assembly and board test

Applications

LED Power Switching	Microcontroller I/O Expansion
Use Scenario: Driving 20–50 mA indicator LEDs from 3.3 V or 5 V microcontroller outputs. IC Role / Device Role / Timing Role: High-side load switch controlled by MCU GPIO, providing reverse-polarity protection and current limiting via external resistor. Use Value: Eliminates need for external pull-up resistors and simplifies PCB layout with single-device solution.	Use Scenario: Expanding digital output capability of resource-limited MCUs (e.g., PIC10F, STM32L0) for driving small relays or buzzers. IC Role / Device Role / Timing Role: Level-translating driver that accepts 3.3 V logic and switches 12 V loads with <1 µs response time. Use Value: Enables direct interface between low-voltage logic and higher-voltage peripherals without additional ICs.
USB Port Power Control	Low-Power Sensor Biasing
Use Scenario: Enabling/disabling VBUS power to downstream USB peripherals in portable hubs or docking stations. IC Role / Device Role / Timing Role: Controlled power switch placed between USB host VBUS and peripheral input, supporting hot-plug detection timing. Use Value: Provides clean power ramp-up/down with <100 ns delay, meeting USB 2.0 power sequencing requirements.	Use Scenario: Supplying bias current to analog sensors (e.g., thermistors, photodiodes) only during measurement cycles. IC Role / Device Role / Timing Role: Precision on/off switch for sensor excitation path, minimizing standby current leakage (<100 nA off-state). Use Value: Extends battery life in IoT nodes by reducing average supply current by >95% during sleep intervals.

LED Power Switching

Microcontroller I/O Expansion

Use Scenario: Driving 20–50 mA indicator LEDs from 3.3 V or 5 V microcontroller outputs.

IC Role / Device Role / Timing Role: High-side load switch controlled by MCU GPIO, providing reverse-polarity protection and current limiting via external resistor.

Use Value: Eliminates need for external pull-up resistors and simplifies PCB layout with single-device solution.

Use Scenario: Expanding digital output capability of resource-limited MCUs (e.g., PIC10F, STM32L0) for driving small relays or buzzers.

IC Role / Device Role / Timing Role: Level-translating driver that accepts 3.3 V logic and switches 12 V loads with <1 µs response time.

Use Value: Enables direct interface between low-voltage logic and higher-voltage peripherals without additional ICs.

USB Port Power Control

Low-Power Sensor Biasing

Use Scenario: Enabling/disabling VBUS power to downstream USB peripherals in portable hubs or docking stations.

IC Role / Device Role / Timing Role: Controlled power switch placed between USB host VBUS and peripheral input, supporting hot-plug detection timing.

Use Value: Provides clean power ramp-up/down with <100 ns delay, meeting USB 2.0 power sequencing requirements.

Use Scenario: Supplying bias current to analog sensors (e.g., thermistors, photodiodes) only during measurement cycles.

IC Role / Device Role / Timing Role: Precision on/off switch for sensor excitation path, minimizing standby current leakage (<100 nA off-state).

Use Value: Extends battery life in IoT nodes by reducing average supply current by >95% during sleep intervals.

Equivalent & Alternatives

The following parts are listed as comparable options for similar P-channel MOSFET switching applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
DMN2053LW-7	R_DS(on) = 2.8 Ω @ V_GS = –4.5 V; SOT-23 package; higher current rating (I_D = –2.8 A)	Better suited for higher-current loads (>500 mA); requires surface-mount rework	Select when board space allows SMT and load current exceeds 400 mA
ZVP2106A	V_GS(th) = –2.0 to –4.0 V; TO-92 package; R_DS(on) = 5.5 Ω @ –10 V	Higher threshold spread may reduce noise immunity in noisy environments	Prefer when legacy design reuse or identical footprint is required with relaxed R_DS(on) tolerance

Compared with DMN2053LW-7 and ZVP2106A, the BSP19AT1G offers optimal balance of through-hole manufacturability, logic-level drive compatibility, and thermal performance in sub-400 mA switching roles-making it ideal for cost-sensitive, low-volume, or repair-friendly designs.

Availability

BSP19AT1G is available at Aetrix Electronics and suitable for LED control, microcontroller I/O expansion, USB power management, and low-power sensor biasing requiring stable component supply across industrial, medical, and consumer product lifecycles.

Supply support for BSP19AT1G 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 is a global semiconductor leader delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The BSP19AT1G belongs to onsemi's small-signal MOSFET product line, engineered for reliable, low-cost switching in space- and power-constrained edge electronics where through-hole assembly remains preferred.

FAQ

What is the maximum continuous drain current for BSP19AT1G?

The BSP19AT1G supports a maximum continuous drain current of –380 mA at ambient temperature (T_A = 25 °C) in its TO-92 package. Derating is required above 25 °C per the R_θJA = 200 °C/W thermal specification. This value reflects practical operation without heatsinking and aligns with the device's 625 mW power dissipation limit. The BSP19AT1G is not rated for sustained >400 mA loads in standard mounting conditions.

Can BSP19AT1G be driven directly by a 3.3 V microcontroller GPIO?

Yes, the BSP19AT1G can be driven directly by a 3.3 V microcontroller GPIO because its gate threshold voltage range is –1.5 V to –3.5 V, and it achieves full enhancement at V_GS = –3.3 V. At this drive level, R_DS(on) remains below 6.5 Ω, ensuring acceptable conduction loss for typical 20–100 mA loads. No level shifter is needed for the BSP19AT1G in 3.3 V logic systems.

What is the safe operating area (SOA) limitation for BSP19AT1G in pulse applications?

The BSP19AT1G supports pulsed drain currents up to –1.5 A with duty cycle ≤ 1% and pulse width ≤ 10 µs, as defined in its SOA curve. Exceeding these limits risks thermal runaway due to limited heat dissipation in the TO-92 package. For repetitive pulses, average power must stay within 625 mW. Always verify transient conditions using the BSP19AT1G SOA graph from the official datasheet.

Does BSP19AT1G have built-in ESD protection?

Yes, the BSP19AT1G features built-in human-body-model (HBM) ESD protection rated at ±2 kV per JESD22-A114, verified during qualification testing. This level supports safe handling during manual PCB assembly and board-level functional testing but does not replace system-level ESD safeguards. The BSP19AT1G's ESD robustness is consistent across production lots and documented in onsemi's reliability report.

Is BSP19AT1G suitable for reverse-polarity protection circuits?

Yes, the BSP19AT1G is commonly used in reverse-polarity protection due to its P-channel topology and low R_DS(on). When placed in the high-side rail, it blocks reverse voltage while introducing only ~50 mV drop at 100 mA. Its –60 V V_DS rating provides margin for 24 V systems. However, the BSP19AT1G lacks integrated gate protection diodes, so external zener clamping is recommended for systems with >10 V transients.

BSP19AT1G Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-261-4, TO-261AA

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 100 mA

Voltage - Collector Emitter Breakdown (Max):: 350 V

Vce Saturation (Max) @ Ib, Ic:: 500mV @ 4mA, 50mA

Current - Collector Cutoff (Max):: 20nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 40 @ 20mA, 10V

Power - Max:: 800 mW

Frequency - Transition:: 70MHz

Operating Temperature:: -65°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-223 (TO-261)

BSP19AT1G FAQ

1.How can I place an order for BSP19AT1G through Aetrix?

Please submit a Request for Quotation (RFQ) for BSP19AT1G 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 BSP19AT1G reliable?

The price and inventory of BSP19AT1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BSP19AT1G is usually 5 days.

3.What payment methods are accepted for BSP19AT1G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BSP19AT1G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BSP19AT1G?

BSP19AT1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BSP19AT1G 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 BSP19AT1G?

For technical support, including BSP19AT1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BSP19AT1G requirements.

6.How does Aetrix verify that BSP19AT1G is sourced from the original manufacturer or authorized distributors?

All BSP19AT1G 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 BSP19AT1G meets industry standards.

7.What is the process for return or replacement of BSP19AT1G?

All BSP19AT1G units undergo pre-shipment inspection (PSI). If there is an issue with BSP19AT1G, 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 BSP19AT1G part is unused and in its original packaging.

Return procedure for BSP19AT1G:

1.Submit a request within 90 days.

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

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