ZXTN04120HFFTA Diodes Inc. Transistor Darlington Pair (SO Transistor Flat Lead) In Stock
The ZXTN04120HFFTA is an NPN medium-power Darlington transistor from Diodes Inc. rated at 120 V collector-emitter voltage, 1 A collector current, and a minimum DC current gain (hFE) of 1000. It is housed in a compact SOT-23 flat-lead (R-PDSO-F3) surface mount package suited for high-gain switching and amplification. Available in lead-free construction with worldwide distribution and competitive pricing.
- Manufacturer
- Diodes Inc.
- Package
- SO Transistor Flat Lead
- Pin Count
- 3
- Lifecycle
- ACTIVE
- Datasheet
- ZXTN04120HFFTA Datasheet PDF
- Category
- Transistor Darlington Pair
- Temp Range
- -55.0°C to 150.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- 120 V collector-emitter breakdown voltage (VCEO) enables reliable operation in high-voltage switching circuits such as relay drivers and solenoid controls
- Minimum DC current gain (hFE) of 1000 in Darlington configuration allows microcontroller I/O pins to directly drive loads up to 1 A without additional driver stages
- Compact flat-lead SOT-23 (R-PDSO-F3) SMT package minimizes board space to approximately 3 mm x 1.7 mm footprint for space-constrained designs
- Low collector-base capacitance of 25 pF maximum supports high-speed switching applications requiring fast turn-on and turn-off transitions
Applications
The ZXTN04120HFFTA is well suited for relay driving, solenoid actuation, and LED matrix control in industrial automation and building management systems, where its 120 V, 1 A rating and hFE of 1000 allow direct control from low-current logic signals. Its Darlington configuration makes it effective in audio amplification, sensor signal conditioning, and motor soft-start circuits where high current gain is critical. The compact SOT-23 package is ideal for portable devices, smart home controllers, and battery-powered IoT equipment requiring efficient signal switching within tight PCB real estate.
Specifications
| Pbfree Code | Yes |
| Factory Lead Time | 12Weeks |
| YTEOL | 4 |
| Collector Current-Max (IC) | 1A |
| Collector-Base Capacitance-Max | 25pF |
| Collector-Emitter Voltage-Max | 120V |
| Configuration | DARLINGTON |
| DC Current Gain-Min (hFE) | 1000 |
| JESD-30 Code | R-PDSO-F3 |
| JESD-609 Code | e3 |
| Number of Elements | 1 |
| Package Body Material | PLASTIC/EPOXY |
| Package Shape | RECTANGULAR |
| Package Style | SMALL OUTLINE |
| Peak Reflow Temperature (Cel) | 260 |
| Polarity/Channel Type | NPN |
| Power Dissipation-Max (Abs) | 1.5W |
| Qualification Status | Not Qualified |
| Reference Standard | MIL-STD-202 |
| Surface Mount | YES |
| Terminal Finish | MATTE TIN |
| Terminal Form | FLAT |
| Terminal Position | DUAL |
| Time@Peak Reflow Temperature-Max (s) | 30 |
| Transistor Application | SWITCHING |
| Transistor Element Material | SILICON |
| Transition Frequency-Nom (fT) | 120MHz |
| VCEsat-Max | 1.5V |
| Package | SO Transistor Flat Lead |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| Moisture Sensitivity Level | MSL 1 |
| ECCN | EAR99 |
| Country of Origin | Mainland China |
Alternate & Equivalent Parts
No known alternates. Submit an RFQ and our team can suggest alternatives.
Frequently Asked Questions
What makes ZXTN04120HFFTA suitable for driving relays or solenoids directly from a microcontroller output?
The ZXTN04120HFFTA's Darlington configuration delivers a minimum DC current gain (hFE) of 1000, meaning a base drive current as low as 1 mA can control a collector load current up to 1 A. Combined with its 120 V VCEO rating, this allows a microcontroller's 3.3 V or 5 V I/O pin to directly switch relay coils and solenoids without an intermediate driver IC, simplifying circuit design and reducing BOM cost.
What is the package type of the ZXTN04120HFFTA and how does it affect PCB layout?
The ZXTN04120HFFTA is housed in an R-PDSO-F3 (flat-lead SOT-23) surface mount package with a footprint of approximately 3 mm x 1.7 mm and a maximum height of 1.1 mm. This compact SMT outline requires minimal PCB pad area, making it straightforward to place on densely routed boards while still achieving adequate thermal dissipation for loads up to 1 A at ambient temperatures below 85°C.
How does the 25 pF collector-base capacitance of the ZXTN04120HFFTA affect switching speed in pulse-width modulation circuits?
With a maximum collector-base capacitance (Ccb) of 25 pF, the ZXTN04120HFFTA supports fast switching transitions suitable for PWM frequencies up to several hundred kilohertz in motor speed control and LED dimming circuits. Lower capacitance reduces the charge that must be supplied or removed at the collector-base junction during switching, enabling rise and fall times typically below 200 ns at 1 A collector current.
When would a designer choose ZXTN04120HFFTA over a single NPN transistor with similar voltage and current ratings?
A designer selects the ZXTN04120HFFTA over a standalone NPN transistor when the available base drive current is severely limited, such as when interfacing with CMOS logic outputs supplying fewer than 5 mA. The Darlington pair's hFE of 1000 or greater amplifies this small drive signal to control collector currents up to 1 A at voltages up to 120 V, eliminating the need for a separate current amplifier stage and reducing component count by at least 2 parts.
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About Diodes Inc.
Diodes Inc. is a leading electronic component manufacturer. FindMyChip sources Diodes Inc. ICs directly from authorized China distributors, offering competitive pricing and reliable stock.
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