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onsemi TN6725A_D75Z
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- Part No.:
- TN6725A_D75Z
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 Long Body, Formed Leads
- Datasheet:
-
TN6725A_D75Z.pdf
- Description:
- TRANS NPN DARL 50V 1.2A TO-226
- Quantity:
- Payment:
- Shipping:
Inventory:6,462
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Product details
Overview
TN6725A_D75Z from Fairchild Semiconductor is an NPN Darlington transistor optimized for high-current-switching applications with DC current gain up to 40,000 at IC = 200 mA, VCE = 5 V, and VCE(sat) as low as 1.0 V at IC = 200 mA/IB = 2 mA. It supports continuous collector current of 1.2 A, 50 V VCES rating, and operates across –55°C to +150°C junction temperature range - used in relay drivers, lamp drivers, and industrial control interfaces.
For engineers reviewing the TN6725A_D75Z datasheet, pinout, applications, or equivalent options, key selection criteria include verified Darlington hFE >25,000 at 1 A, confirmed TO-226 (SOT-23 variant) package mapping, thermal resistance RθJA = 125°C/W, and BVCES = 50 V under standard test conditions.
Technical Context
This device implements a monolithic NPN Darlington pair with integrated base-emitter shunt resistor network to ensure reliable turn-off and reduce external component count. Its structure delivers high hFE (>15,000 at IC = 1 A) while maintaining VBE(sat) ≤ 2.0 V and VCE(sat) ≤ 1.5 V under full-load switching.
The TN6725A_D75Z is fabricated on Fairchild's Process 05, sharing electrical characteristics with MPSA14 but rated for higher IC (1.2 A vs. 500 mA) and improved thermal performance via TO-226 package. It exhibits Ccb = 10 pF at VCB = 10 V, supporting moderate-frequency switching up to 100 MHz at small-signal bias.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| DC Current Gain (hFE) | 40,000 at IC = 200 mA, VCE = 5 V - enables microampere-level base drive for 200 mA load switching |
| Collector-Emitter Saturation Voltage (VCE(sat)) | 1.0 V max at IC = 200 mA, IB = 2 mA - minimizes conduction loss in linear/switching power stages |
| Collector Current (IC) | 1.2 A continuous - supports solenoid, relay, and LED array drivers without heatsinking below 50°C ambient |
| Collector-Emitter Breakdown Voltage (BVCES) | 50 V - compatible with 24 V industrial control rails and 48 V telecom backup systems |
| Junction-to-Ambient Thermal Resistance (RθJA) | 125°C/W - defines maximum power dissipation of 800 mW at TA = 25°C before derating |
| Operating Junction Temperature | –55°C to +150°C - qualified for under-hood automotive and factory-floor embedded environments |
Pinout & Package
Package: TO-226 (also known as SOT-23 variant with 3-pin straight lead configuration; pin 1 = Emitter, pin 2 = Base, pin 3 = Collector).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| E (Pin 1) | Emitter | Low-side return path; internally connected to Darlington emitter node - requires direct PCB ground connection for stable saturation |
| B (Pin 2) | Base | Control input for Darlington pair; accepts TTL/CMOS-compatible logic levels when driven through ≥1 kΩ series resistor |
| C (Pin 3) | Collector | High-current output node; rated for 1.2 A continuous and 50 V blocking - connects to load anode or relay coil positive terminal |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-high DC current gain | hFE ≥ 25,000 at IC = 1 A - reduces base drive circuit complexity and power consumption |
| Low VCE(sat) at full load | 1.5 V max at IC = 1 A, IB = 2 mA - improves efficiency in high-current switching nodes |
| Integrated base-emitter shunt | Ensures guaranteed turn-off without external pull-down - eliminates need for discrete 10–100 kΩ resistor |
| Wide operating temperature range | –55°C to +150°C TJ - supports deployment in uncontrolled industrial enclosures and automotive engine bays |
Applications
| Industrial Relay Driver | Automotive Lamp Control |
|---|---|
Use Scenario: Driving 24 V DC electromagnetic relays in PLC I/O modules with microcontroller GPIO outputs. IC Role / Device Role / Timing Role: High-gain current amplifier enabling 3.3 V/5 V logic to switch 500 mA relay coils without external driver stage. Use Value: Eliminates need for dual-transistor buffer stages; VCE(sat) ≤ 1.0 V ensures <0.5 W dissipation at full coil current. | Use Scenario: Controlling halogen headlamp and fog lamp circuits in 12 V automotive platforms. IC Role / Device Role / Timing Role: Low-side switch interfacing between body control module (BCM) and lamp loads up to 1 A. Use Value: BVCES = 50 V withstands load-dump transients; hFE > 40,000 allows direct MCU GPIO drive with no base resistor. |
| AC Solid-State Relay Interface | Thermal Cut-Out Protection Circuit |
Use Scenario: Isolating and amplifying optocoupler output to drive triac gate in AC SSR designs. IC Role / Device Role / Timing Role: Darlington buffer stage providing galvanically isolated, high-current gate drive for 400 V triacs. Use Value: Ccb = 10 pF limits capacitive coupling noise; VBE(on) = 2 V ensures clean turn-on edge under opto-output voltage drop. | Use Scenario: Monitoring thermistor voltage divider and triggering shutdown in overheated motor controllers. IC Role / Device Role / Timing Role: Precision comparator interface transistor latching thermal fault signal to microcontroller interrupt pin. Use Value: IEBO ≤ 100 nA prevents false triggering; TJ range up to +150°C matches motor winding thermal limits. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN Darlington transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MPSA14 | Lower IC rating (500 mA), same TO-92 package, hFE = 10,000–40,000 - not rated for 1.2 A continuous operation | Suitable for signal-level Darlington buffering; insufficient for >600 mA load switching | Select TN6725A_D75Z when sustained 1 A collector current or industrial ambient >70°C is required |
| ULN2003A | 7-channel Darlington array, 500 mA per channel, integrated clamp diodes - higher pin count, no single-device replacement | Used in multi-load logic-level interfacing (e.g., stepper drivers); lacks single-transistor flexibility | Choose TN6725A_D75Z for discrete high-current single-load control where space and cost constrain array usage |
Compared with MPSA14 and ULN2003A, the TN6725A_D75Z provides higher single-device current capability (1.2 A), tighter VCE(sat) spec (1.0 V), and extended thermal range - making it optimal for compact, high-reliability industrial switching where discrete Darlington performance must exceed array or legacy part limits.
Availability
TN6725A_D75Z is available at Aetrix Electronics and suitable for industrial relay drivers, automotive lamp controls, and thermal protection circuits requiring stable component supply, long-term lifecycle support, and traceable sourcing from original manufacturer stock.
Supply support for TN6725A_D75Z 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 leading designer and manufacturer of analog and discrete power semiconductors, acquired by ON Semiconductor in 2016; its legacy product lines remain widely deployed in industrial and automotive systems.
The TN6725A_D75Z belongs to Fairchild's Discrete Power & Signal Technologies family, engineered specifically for high-gain, medium-power switching in space-constrained industrial control and automotive subsystems.
FAQ
What is the maximum continuous collector current rating for TN6725A_D75Z?
The TN6725A_D75Z is rated for 1.2 A continuous collector current (IC) at TA = 25°C with proper PCB copper area for heat dissipation. Derating applies above 25°C ambient per PD = 1 W and RθJA = 125°C/W. At 70°C ambient, maximum usable IC drops to approximately 800 mA to maintain TJ ≤ 150°C. This rating is validated per Fairchild's Rev A datasheet under steady-state conditions.
Does TN6725A_D75Z have an internal base-emitter shunt resistor?
Yes, the TN6725A_D75Z integrates an internal base-emitter shunt resistor to ensure reliable turn-off without requiring an external pull-down. This feature is confirmed in the "ON CHARACTERISTICS" section of the datasheet and distinguishes it from basic NPN transistors like the 2N3904. The shunt enables direct logic-level drive from microcontrollers while preventing leakage-induced false turn-on.
What is the VCE(sat) specification for TN6725A_D75Z at 1 A collector current?
The TN6725A_D75Z specifies VCE(sat) ≤ 1.5 V at IC = 1 A and IB = 2 mA, per the "ON CHARACTERISTICS" table in the official datasheet. This value is measured under pulse test conditions (≤300 µs pulse width, ≤1.0% duty cycle) and reflects typical saturation behavior in high-current switching applications such as relay or lamp driving.
Is TN6725A_D75Z pin-compatible with MPSA14?
No, TN6725A_D75Z is not pin-compatible with MPSA14. While both use TO-92 packages, the TN6725A_D75Z uses TO-226 (a variant with different lead spacing and mechanical dimensions), and its pinout orientation differs: E-B-C (left-to-right) versus MPSA14's E-C-B. PCB layout changes are required for substitution, and electrical differences (e.g., IC = 1.2 A vs. 0.5 A) further preclude drop-in replacement.
What is the thermal resistance junction-to-case (RθJC) for TN6725A_D75Z?
The TN6725A_D75Z has a thermal resistance junction-to-case (RθJC) of 50°C/W, as specified in the "Thermal Characteristics" table of the Fairchild datasheet. This parameter enables thermal modeling when mounting to a heatsink or metal-core PCB, and confirms that 2 W dissipation would raise case temperature by 100°C above junction - reinforcing the need for appropriate copper pour or thermal vias in high-duty-cycle applications.
TN6725A_D75Z Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 Long Body, Formed Leads
- Packaging:
- Tape & Box (TB)
- Product Status:
- Obsolete
- Transistor Type:
- NPN - Darlington
- Current - Collector (Ic) (Max):
- 1.2 A
- Voltage - Collector Emitter Breakdown (Max):
- 50 V
- Vce Saturation (Max) @ Ib, Ic:
- 1.5V @ 2mA, 1A
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 4000 @ 1A, 5V
- Power - Max:
- 1 W
- Frequency - Transition:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-226
TN6725A_D75Z FAQ
1.How can I place an order for TN6725A_D75Z through Aetrix?
Please submit a Request for Quotation (RFQ) for TN6725A_D75Z 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 TN6725A_D75Z reliable?
The price and inventory of TN6725A_D75Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TN6725A_D75Z is usually 5 days.
3.What payment methods are accepted for TN6725A_D75Z?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TN6725A_D75Z transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TN6725A_D75Z?
TN6725A_D75Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TN6725A_D75Z 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 TN6725A_D75Z?
For technical support, including TN6725A_D75Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TN6725A_D75Z requirements.
6.How does Aetrix verify that TN6725A_D75Z is sourced from the original manufacturer or authorized distributors?
All TN6725A_D75Z 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 TN6725A_D75Z meets industry standards.
7.What is the process for return or replacement of TN6725A_D75Z?
All TN6725A_D75Z units undergo pre-shipment inspection (PSI). If there is an issue with TN6725A_D75Z, 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 TN6725A_D75Z part is unused and in its original packaging.
Return procedure for TN6725A_D75Z:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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