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onsemi MPSW45
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- Part No.:
- MPSW45
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 Long Body
- Datasheet:
-
MPSW45.pdf
- Description:
- TRANS NPN DARL 40V 1A TO92
- Quantity:
- Payment:
- Shipping:
Inventory:6,520
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Product details
Overview
MPSW45 from onsemi is an NPN silicon Darlington transistor in a TO-92 package, rated for 1.0 W total device dissipation at TA = 25°C, 40 V C-E breakdown voltage, and 1.0 A continuous collector current. It delivers high DC current gain (hFE ≥ 25,000 at IC = 200 mA), low saturation voltage (VCE(sat) ≤ 1.5 V), and operates across −55°C to +150°C junction temperature - used in low-power linear amplification and relay driver circuits.
For engineers reviewing the MPSW45 datasheet, pinout, applications, or equivalent options, this page provides verified electrical specifications, thermal performance data, TO-92 terminal mapping, noise characteristics, and validated alternative parts for industrial control and signal amplification designs.
Technical Context
The MPSW45 implements a monolithic NPN Darlington pair with integrated base-emitter resistor network, enabling high current gain without external bias components. Its structure supports low-input-drive switching and analog amplification with fT = 100 MHz and Ccb ≤ 6.0 pF at 10 V reverse bias.
Thermal design is constrained by RθJA = 125°C/W and RθJC = 50°C/W, requiring careful PCB copper area planning for sustained 1.0 A operation. The device exhibits wideband noise voltage < 2.0 nV/√Hz at RS ≈ 0 and IC = 1.0 mA, making it suitable for low-noise preamplifier stages where gain stability matters more than RF bandwidth.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Collector–Emitter Voltage (VCES) | 40 Vdc - maximum safe voltage across C–E before breakdown; defines upper rail limit in relay drivers and linear regulators. |
| Continuous Collector Current (IC) | 1.0 Adc - usable for driving 500–800 mA loads with margin; requires heatsinking above 500 mA ambient operation. |
| DC Current Gain (hFE) | 25,000 min @ IC = 200 mAdc - enables microampere-level base drive for 1 A output; reduces MCU GPIO loading. |
| Collector–Emitter Saturation Voltage (VCE(sat)) | ≤1.5 Vdc @ IC = 1.0 A, IB = 2.0 mA - limits power loss to ≤1.5 W at full load; critical for efficiency in battery-powered switches. |
| Thermal Resistance (RθJA) | 125°C/W - implies ~125°C rise per watt at ambient; mandates minimum 1 cm² 2-oz copper pad for 1 W continuous use. |
| Transition Frequency (fT) | 100 MHz - supports audio and sub-MHz switching; insufficient for RF but adequate for PWM motor control up to 20 kHz. |
| Emitter–Base Breakdown (VEBO) | 12 Vdc - restricts base drive voltage range; requires Zener clamping if driven from >12 V logic sources. |
Pinout & Package
Package: TO-92 (Case 29-10), through-hole, 1 W rating, Pb-free option available (MPSW45G). Standard lead form is bent-lead; straight-lead and tape-and-reel variants also offered.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Emitter terminal of Darlington pair | Low-impedance output node; connects to ground or load return; must be routed with low-inductance path for fast switching. |
| 2 (Base) | Input control terminal | Drives internal Darlington base; accepts 2 mA typical for 1 A output; requires series resistor to limit IB under overvoltage conditions. |
| 3 (Collector) | High-current output terminal | Connects to load high-side; handles full 1 A load current; thermal path routes through leadframe to PCB copper. |
Key Features
| Feature | Design Value |
|---|---|
| Monolithic Darlington architecture | Integrates two NPN transistors and base-emitter resistor on single die - eliminates discrete layout complexity and matching errors. |
| High hFE with low VBE(sat) | Delivers ≥25,000 gain while maintaining VBE(sat) ≤ 2.0 V - enables direct drive from 3.3 V or 5 V logic without level-shifting. |
| Wide operating temperature range | −55°C to +150°C TJ - supports deployment in automotive engine compartments and industrial enclosures without derating. |
| Low noise performance | en < 2.0 nV/√Hz at 1 kHz, RS ≈ 0 - preserves SNR in microphone preamps and sensor signal conditioning front-ends. |
| Pb-free packaging compliance | RoHS-compliant TO-92 variant (MPSW45G) available - meets EU Directive 2011/65/EU and IPC-J-STD-609A requirements. |
Applications
| Relay Driver Circuit | Low-Noise Audio Preamp |
|---|---|
|
Use Scenario: Driving 12 V, 500 mA electromagnetic relay coil from a microcontroller GPIO pin. IC Role / Device Role / Timing Role: High-gain current amplifier translating 3.3 V/2 mA logic signal into 12 V/500 mA coil current. Use Value: Eliminates need for dual-transistor stage; reduces BOM count and board space while ensuring reliable relay pull-in at low supply voltages. |
Use Scenario: First-stage amplification of electret microphone output in battery-powered voice recorder. IC Role / Device Role / Timing Role: Low-noise, high-input-impedance common-emitter amplifier with DC-coupled biasing. Use Value: Achieves < 2.0 nV/√Hz input-referred noise at 1 kHz, preserving dynamic range without requiring op-amp buffering. |
| Linear Voltage Regulator Pass Element | Industrial Sensor Interface |
|
Use Scenario: Pass transistor in adjustable 5 V linear regulator supplying 800 mA to analog sensor subsystem. IC Role / Device Role / Timing Role: Series pass element controlled by error amplifier feedback loop; dissipates up to 1.2 W. Use Value: VCE(sat) ≤ 1.5 V minimizes dropout and heat generation; RθJC = 50°C/W allows direct mounting to metal chassis for thermal relief. |
Use Scenario: Signal conditioning stage for 4–20 mA current-loop transmitter output in PLC analog input module. IC Role / Device Role / Timing Role: Transimpedance amplifier input stage converting loop current to voltage with stable gain. Use Value: hFE ≥ 25,000 ensures minimal base current error (< 40 nA), maintaining ±0.1% accuracy across temperature and supply variations. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Darlington transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMBT4401 | Single NPN, hFE = 100–300, VCES = 40 V, PD = 0.35 W - lower gain, lower power, no Darlington structure. | Suitable only for low-current switching (≤200 mA); cannot replace MPSW45 in 1 A relay or linear regulator roles. | Select when cost sensitivity outweighs gain requirement and load current stays below 200 mA. |
| ULN2003A | 7-channel Darlington array, 500 mA per channel, integrated clamp diodes, 16-pin SOIC - not discrete, higher integration, different footprint. | Used in multi-load digital I/O expansion; lacks analog linearity and low-noise specs needed for preamp or precision regulation. | Choose for parallel relay/motor control where board space permits IC solution and individual channel isolation is required. |
Compared with MMBT4401 and ULN2003A, the MPSW45 uniquely balances high DC gain, 1 A capability, TO-92 compatibility, and low-noise analog performance - making it irreplaceable in single-channel, medium-power linear or switching applications demanding simplicity and thermal headroom.
Availability
MPSW45 is available at Aetrix Electronics and suitable for relay driver circuits, low-noise audio preamplifiers, and linear voltage regulator pass elements requiring stable component supply, long-lifecycle support, and RoHS-compliant sourcing.
Supply support for MPSW45 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 MPSW45 belongs to onsemi's legacy bipolar transistor product line designed for cost-sensitive, medium-power linear and switching applications where high current gain and robust thermal performance are essential.
FAQ
What is the maximum continuous collector current rating for the MPSW45?
The MPSW45 is rated for 1.0 A continuous collector current (IC) at TA = 25°C. Derating is required above 25°C ambient - 8.0 mW/°C for ambient-limited operation and 20 mW/°C for case-limited operation. At 75°C ambient, usable current drops to approximately 600 mA under standard PCB mounting conditions. Always verify thermal design using RθJA = 125°C/W and actual board copper area.
Does the MPSW45 have built-in base-emitter resistors?
Yes, the MPSW45 integrates a monolithic Darlington structure with internal base-emitter resistor networks that stabilize bias and reduce external component count. This differs from discrete transistor pairs and enables predictable hFE behavior without external bias resistors - confirmed in the "ON CHARACTERISTICS" section of the official datasheet (MPSW45/D, Rev. 4).
Can the MPSW45 be used as a direct replacement for the MPSW45A?
No - the MPSW45 and MPSW45A are not interchangeable without circuit review. The MPSW45A has higher voltage ratings (VCES = 50 V, VCBO = 60 V) and identical pinout/package, but its higher breakdown margins do not guarantee identical gain or saturation behavior at 40 V operation. Use MPSW45A only when 50 V C–E standoff is required; otherwise, MPSW45 remains optimal for 40 V systems.
What is the typical noise performance of the MPSW45 in audio applications?
The MPSW45 delivers input-referred voltage noise < 2.0 nV/√Hz at 1 kHz with RS ≈ 0 and IC = 1.0 mA, as shown in Figure 2 of the datasheet. This makes it suitable for electret microphone preamplifiers and sensor front-ends where low-noise analog gain is critical. Noise increases with source resistance - at RS = 1 kΩ, total wideband noise rises to ~8.0 nV RMS (10 Hz–15.7 kHz band).
Is the TO-92 package of the MPSW45 compatible with automated through-hole assembly?
Yes - the MPSW45 in TO-92 (Case 29-10) is compatible with standard through-hole insertion equipment. Bent-lead (Style 1) and straight-lead variants are both supported, and tape-and-reel packaging (e.g., MPSW45RLREG) is available for pick-and-place feeders. Lead pitch matches IPC-7351 standards, and thermal pad recommendations align with industry wave-solder profiles.
MPSW45 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:
- NPN - Darlington
- Current - Collector (Ic) (Max):
- 1 A
- Voltage - Collector Emitter Breakdown (Max):
- 40 V
- Vce Saturation (Max) @ Ib, Ic:
- 1.5V @ 2mA, 1A
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 25000 @ 200mA, 5V
- Power - Max:
- 1 W
- Frequency - Transition:
- 100MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92 (TO-226)
MPSW45 FAQ
1.How can I place an order for MPSW45 through Aetrix?
Please submit a Request for Quotation (RFQ) for MPSW45 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 MPSW45 reliable?
The price and inventory of MPSW45 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MPSW45 is usually 5 days.
3.What payment methods are accepted for MPSW45?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MPSW45 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MPSW45?
MPSW45 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MPSW45 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 MPSW45?
For technical support, including MPSW45 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MPSW45 requirements.
6.How does Aetrix verify that MPSW45 is sourced from the original manufacturer or authorized distributors?
All MPSW45 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 MPSW45 meets industry standards.
7.What is the process for return or replacement of MPSW45?
All MPSW45 units undergo pre-shipment inspection (PSI). If there is an issue with MPSW45, 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 MPSW45 part is unused and in its original packaging.
Return procedure for MPSW45:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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