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

onsemi MPSW51G

Name: MPSW51G
Brand: onsemi
SKU: MPSW51G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MPSW51G

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-226-3, TO-92-3 Long Body

Datasheet:: MPSW51G.pdf

Description:: TRANS PNP 30V 1A TO92

Quantity:: RFQ Add To RFQ list

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Product details

Overview

MPSW51G from onsemi is a PNP silicon bipolar junction transistor rated for −1000 mA continuous collector current, −30 V collector-emitter breakdown voltage (V_(BR)CEO), and 1.0 W total device dissipation at T_A = 25°C, used in medium-power linear and switching applications such as DC-DC converter bias circuits and relay drivers.

For engineers reviewing the MPSW51G datasheet, pinout, applications, or equivalent options, key selection criteria include its TO-92 package thermal resistance (R_JA = 125°C/W), guaranteed h_FE ≥ 55 at −10 mA, V_CE(sat) ≤ −0.7 V at −1000 mA/−100 mA drive, and Pb-free RoHS-compliant construction.

Technical Context

The MPSW51G operates as a general-purpose PNP BJT with fixed gain structure optimized for high-current saturation switching and linear amplification up to 50 MHz f_T. Its safe operating area (SOA) is defined by thermal limits (T_J = −55°C to +150°C), second breakdown constraints, and current-limited boundaries per Figure 7 of the datasheet.

It features low V_BE(on) (≤ −1.2 V at −1000 mA), tight V_(BR)CEO tolerance (−30 V min), and C_obo = 30 pF at −10 V, supporting stable operation in low-noise analog stages and fast-switching digital interfaces where base drive efficiency and output capacitance matter.

Key Specifications

Parameter	Value and Actual Design Meaning
V_(BR)CEO	−30 V - Maximum reverse-biased collector-emitter voltage before breakdown; sets upper limit for supply rail compatibility in PNP switch designs.
I_C Continuous	−1000 mA - Sustained collector current capability; supports load switching up to ~1 A with appropriate heatsinking.
P_D @ T_A = 25°C	1.0 W - Power dissipation limit at ambient; requires derating above 25°C (8.0 mW/°C) for reliable thermal management.
h_FE	55 min at −10 mA - Minimum DC current gain ensures predictable base drive sizing for saturation in switching applications.
V_CE(sat)	≤ −0.7 V at −1000 mA/−100 mA - Low saturation voltage minimizes conduction loss and self-heating in high-current ON states.
f_T	50 MHz - Transition frequency enables use in audio-frequency amplifiers and moderate-speed digital logic interfaces.

Pinout & Package

Package: TO-92 (Case 29-10, Style 1), 1 W rating, Pb-free, through-hole mounting. Pin configuration confirmed per datasheet mechanical outline (Page 3): Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current source terminal for PNP device	Connected to higher potential rail in common-emitter configurations; determines reference point for base bias network.
2 (Base)	Control electrode for minority-carrier injection	Receives current-limited drive signal; requires series resistor to limit I_B and ensure saturation under worst-case h_FE.
3 (Collector)	Current sink terminal	Typically tied to load and ground return path; must withstand full V_CE stress during OFF state.

Key Features

Feature	Design Value
Pb-free and RoHS compliant	Meets EU Directive 2011/65/EU; eliminates lead contamination risk in automated soldering and end-of-life recycling.
Guaranteed V_(BR)CEO ≥ −30 V	Enables direct replacement in legacy −24 V or −28 V industrial control circuits without overvoltage risk.
R_JA = 125°C/W	Allows estimation of junction temperature rise under known power dissipation; informs heatsink necessity in enclosed environments.
V_BE(on) ≤ −1.2 V	Reduces required base drive voltage headroom, simplifying interface with 3.3 V or 5 V microcontroller GPIOs.
C_obo = 30 pF	Limits Miller effect in high-frequency switching; maintains stability in feedback amplifier topologies.

Applications

Industrial Relay Driver	Linear Voltage Regulator Pass Element
Use Scenario: Driving 24 VDC coil relays in programmable logic controller (PLC) output modules. IC Role / Device Role / Timing Role: PNP switch controlling coil current path to ground; operates in saturation and cutoff states. Use Value: −1000 mA I_C rating supports standard 24 V/500 mW relays; low V_CE(sat) reduces heat generation during sustained ON periods.	Use Scenario: Series pass transistor in adjustable negative LDO regulators delivering −5 V to −15 V at up to 500 mA. IC Role / Device Role / Timing Role: Linear regulator pass element dissipating excess voltage as heat; biased in active region. Use Value: h_FE ≥ 55 ensures stable current amplification across temperature; R_JC = 50°C/W supports thermal coupling to PCB copper pour.
DC-DC Converter Bias Circuit	Audio Preamp Stage
Use Scenario: Providing base drive to main power MOSFETs in isolated flyback or forward converter auxiliary supplies. IC Role / Device Role / Timing Role: High-current PNP driver stage translating PWM logic levels to gate drive signals. Use Value: f_T = 50 MHz allows clean pulse response up to ~5 MHz switching frequencies; low C_obo prevents gate oscillation.	Use Scenario: First-stage low-noise amplifier in battery-powered portable audio equipment. IC Role / Device Role / Timing Role: Common-emitter small-signal amplifier with emitter degeneration for gain stability. Use Value: Guaranteed h_FE and low V_CE(sat) enable consistent DC bias point; TO-92 package simplifies hand-soldered prototyping.

Industrial Relay Driver

Linear Voltage Regulator Pass Element

Use Scenario: Driving 24 VDC coil relays in programmable logic controller (PLC) output modules.

IC Role / Device Role / Timing Role: PNP switch controlling coil current path to ground; operates in saturation and cutoff states.

Use Value: −1000 mA I_C rating supports standard 24 V/500 mW relays; low V_CE(sat) reduces heat generation during sustained ON periods.

Use Scenario: Series pass transistor in adjustable negative LDO regulators delivering −5 V to −15 V at up to 500 mA.

IC Role / Device Role / Timing Role: Linear regulator pass element dissipating excess voltage as heat; biased in active region.

Use Value: h_FE ≥ 55 ensures stable current amplification across temperature; R_JC = 50°C/W supports thermal coupling to PCB copper pour.

DC-DC Converter Bias Circuit

Audio Preamp Stage

Use Scenario: Providing base drive to main power MOSFETs in isolated flyback or forward converter auxiliary supplies.

IC Role / Device Role / Timing Role: High-current PNP driver stage translating PWM logic levels to gate drive signals.

Use Value: f_T = 50 MHz allows clean pulse response up to ~5 MHz switching frequencies; low C_obo prevents gate oscillation.

Use Scenario: First-stage low-noise amplifier in battery-powered portable audio equipment.

IC Role / Device Role / Timing Role: Common-emitter small-signal amplifier with emitter degeneration for gain stability.

Use Value: Guaranteed h_FE and low V_CE(sat) enable consistent DC bias point; TO-92 package simplifies hand-soldered prototyping.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MPSW51AG	V_(BR)CEO = −40 V (vs. −30 V); otherwise identical electrical specs and TO-92 package.	Supports higher supply rails (e.g., −36 V systems); same pinout and footprint.	Select MPSW51AG when operating above −30 V collector-emitter stress is required; no layout change needed.
BC557B	Lower I_C = −100 mA; h_FE = 200–450; V_(BR)CEO = −45 V; same TO-92 package but not pin-compatible (Emitter/Base/Collector order differs).	Suitable only for low-current signal amplification, not power switching.	Use BC557B only in low-power analog stages; verify pin mapping before substitution-MPSW51G has E-B-C (Pin 1–2–3), BC557B has E-C-B.

Compared with MPSW51AG and BC557B, the MPSW51G offers optimal balance of high current handling (−1000 mA), moderate voltage rating (−30 V), and standardized TO-92 E-B-C pinout-making it preferred for cost-sensitive, medium-power industrial switching where thermal margin and drive simplicity are critical.

Availability

MPSW51G is available at Aetrix Electronics and suitable for industrial relay drivers, linear voltage regulator pass elements, and DC-DC converter bias circuits requiring stable component supply, long-term manufacturability, and RoHS-compliant sourcing.

Supply support for MPSW51G 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 management, analog, sensing, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.

The MPSW51G belongs to onsemi's general-purpose bipolar transistor product line, designed specifically for cost-effective, high-reliability discrete switching and amplification in industrial control, power conversion, and instrumentation applications.

FAQ

What is the maximum continuous collector current rating for the MPSW51G?

The MPSW51G is rated for −1000 mA (−1 A) continuous collector current at T_A = 25°C. This rating assumes proper PCB copper area for heat dissipation and derating per the 8.0 mW/°C slope above ambient temperature. Exceeding this current without thermal mitigation risks junction overheating and permanent degradation of the MPSW51G.

Is the MPSW51G pin-compatible with the MPSW51AG?

Yes, the MPSW51G and MPSW51AG share identical TO-92 package dimensions, pinout (Emitter-Base-Collector on Pins 1-2-3), and mechanical marking layout. The only difference is the higher −40 V V_(BR)CEO rating of the MPSW51AG; all other electrical parameters and thermal characteristics match those of the MPSW51G.

Does the MPSW51G require a heatsink in typical applications?

The MPSW51G does not require an external heatsink when dissipating ≤ 1.0 W at T_A = 25°C with adequate PCB copper (≥ 1 in² 2 oz Cu). However, at elevated ambient temperatures or sustained >500 mA loads, thermal simulation using R_JA = 125°C/W is recommended to confirm T_J remains below 150°C for reliable operation of the MPSW51G.

What is the guaranteed minimum DC current gain (h_FE) for the MPSW51G?

The MPSW51G guarantees h_FE ≥ 55 at I_C = −10 mA and V_CE = −1.0 Vdc, per the Electrical Characteristics table. At higher currents (−100 mA and −1000 mA), minimum h_FE drops to 60 and 50 respectively-values critical for calculating worst-case base drive requirements in saturated switch designs using the MPSW51G.

Can the MPSW51G be used in surface-mount designs?

No-the MPSW51G is exclusively offered in the through-hole TO-92 (Case 29-10) package, as confirmed by the Ordering Information table. It lacks SMT variants like SOT-23 or SC-70. For surface-mount alternatives, engineers should evaluate functionally similar PNP transistors such as the NSS12201LT1G (SOT-23) while verifying gain, voltage, and thermal performance against the MPSW51G specifications.

MPSW51G Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 Long Body

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: PNP

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

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

Vce Saturation (Max) @ Ib, Ic:: 700mV @ 100mA, 1A

Current - Collector Cutoff (Max):: 100nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 60 @ 100mA, 1V

Power - Max:: 1 W

Frequency - Transition:: 50MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92 (TO-226)

MPSW51G FAQ

1.How can I place an order for MPSW51G through Aetrix?

Please submit a Request for Quotation (RFQ) for MPSW51G 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 MPSW51G reliable?

The price and inventory of MPSW51G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MPSW51G is usually 5 days.

3.What payment methods are accepted for MPSW51G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MPSW51G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MPSW51G?

MPSW51G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MPSW51G 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 MPSW51G?

For technical support, including MPSW51G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MPSW51G requirements.

6.How does Aetrix verify that MPSW51G is sourced from the original manufacturer or authorized distributors?

All MPSW51G 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 MPSW51G meets industry standards.

7.What is the process for return or replacement of MPSW51G?

All MPSW51G units undergo pre-shipment inspection (PSI). If there is an issue with MPSW51G, 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 MPSW51G part is unused and in its original packaging.

Return procedure for MPSW51G:

1.Submit a request within 90 days.

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

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