TUHS3F12 - 3W 12V 250mA PCB Mount AC-DC Converter | Cosel
MPN: TUHS3F12 β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.5 | $18.50 |
| 10 | $17.2 | $172.00 |
| 100 | $15.8 | $1,580.00 |
| 500 | $14.6 | $7,300.00 |
| 1,000 | $13.4 | $13,400.00 |
TUHS3F12 Overview
An AC-DC converter (also called an off-line power supply module) converts mains alternating current into a low-voltage regulated direct-current output. Within the power-management hierarchy, it sits above DC-DC converters, which only convert an already-rectified DC rail; an AC-DC module handles rectification, power-factor correction, isolation, regulation, and protection in a single encapsulated package.
Key features of the TUHS3F12 include built-in overcurrent and overvoltage protection circuits, a small footprint that greatly reduces board area, and design flexibility for hold-up time and expected life. Cosel's series documentation highlights low-noise technology and soft switching circuits that achieve high efficiency and low standby power across the TUHS range (3 W to 30 W). Notably, the module is not built with aluminum or tantalum electrolytic capacitors, which improves long-term reliability and extends expected service life compared with conventional designs.
Technically, the TUHS3F12 is a member of the 3 W tier of the TUHS family; larger family members such as the TUHS25 employ synchronous rectification for further efficiency gains. The universal input permits direct connection to worldwide single-phase mains without jumper selection, making the module suitable for globally deployed equipment. The encapsulated through-hole construction provides resistance to dust, moisture, and vibration.
Typical applications include industrial control equipment, household appliances, network and communication devices, LED lighting drivers, and instrumentation where a compact, isolated low-power auxiliary supply is required directly on the main PCB.
A key design consideration is thermal derating: at 3 W output the module must be mounted with adequate airflow and spacing to keep case temperature within the datasheet limit, and output current should not exceed 250 mA continuously. Hold-up time can be extended with an external output capacitor per Cosel's application guidance.
This page synthesizes distributor pricing, drop-in family alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for TUHS3F12 β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
TUHS3F05
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
TUHS3F15
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
TUHS3F24
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
TUHS3F12 Maximum Ratings & Electrical Characteristics
| Output Power | 3 W |
| Number of Outputs | 1 |
| Output Voltage | 12 V |
| Output Current | 250 mA |
| Input Voltage Range (AC) | 85 VAC to 264 VAC |
| Input Voltage Range (DC) | 120 VDC to 370 VDC |
| Input Frequency | 50/60 Hz |
| Protection Features | Overcurrent, Overvoltage |
| Electrolytic Capacitors | Not built-in (aluminum and tantalum) |
| Series | TUHS (3 W to 30 W) |
| Mounting Type | PCB Mount, Through Hole |
| Construction | Encapsulated |
| Efficiency Technology | Low noise technology and soft switching circuits |
| RoHS Status | Compliant |
TUHS3F12 standard Pin Configuration Guide
Pin configuration for TUHS3F12 (standard package). This power device features gate, drain, and source terminals. For non-polarized packages, refer to the manufacturer datasheet for exact pin 1 orientation and footprint details. Common applications include power supply design, motor driving, and load switching.
No detailed pinout data available for TUHS3F12.
Refer to the datasheet for full pin configuration.
Typical Applications
TUHS3F12 is suitable for 6 applications: Industrial Control Auxiliary Power, Home Appliances and White Goods, Network and Communication Equipment, LED Lighting Drivers, Test and Measurement Instrumentation, Security and Surveillance Systems.
Industrial Control Auxiliary Power
The TUHS3F12 fits industrial control boards as an auxiliary 12 V supply because its 85 to 264 VAC universal input connects directly to plant mains without selection jumpers, and its built-in overcurrent and overvoltage protection guards downstream logic during faults. In a PLC I/O board, the module typically powers microcontroller circuitry, relay coil drivers, and status indicators, while a downstream DC-DC converter steps down to 5 V or 3.3 V for processors. The encapsulated through-hole construction withstands dust and vibration common on factory floors, and the absence of aluminum or tantalum electrolytic capacitors extends service life in elevated-temperature cabinets. Placement near the AC entry point with at least 6 mm creepage clearance and adequate copper pour keeps the module within its thermal derating limits at the full 250 mA continuous load.
Recommended
Home Appliances and White Goods
Appliance main boards require a small, reliable, always-on standby supply, and the TUHS3F12 serves this role with its 3 W output and 12 V/250 mA rail for relays, motors control, and user-interface electronics. Cosel's low-noise technology and soft-switching circuits reduce conducted EMI, easing compliance with household emissions requirements, while the universal 85 to 264 VAC input lets one board design ship worldwide at 100, 120, 230, and 240 V mains. Because the TUHS3 design omits aluminum and tantalum electrolytic capacitors, it avoids the classic dry-out failure mode in hot appliance enclosures near ovens or motors, improving expected life. The encapsulated package also resists moisture and cleaning-solvent exposure during manufacturing. Designers should derate output current at high ambient temperatures per the datasheet derating curve.
Recommended
Network and Communication Equipment
Compact network devices such as Ethernet extenders, small routers, and telemetry gateways benefit from the TUHS3F12's low-profile PCB-mount format: the mains conversion happens directly on the main board, eliminating an external wall adapter and reducing bill-of-materials complexity. The 12 V/250 mA output powers fanless processors, PHY chips, and PoE-passthrough control circuits, while the 85 to 264 VAC input accommodates deployment anywhere in the world. Built-in overvoltage protection protects sensitive silicon during input transients. Cosel's documented design flexibility for hold-up time allows adding external output capacitance so the system rides through short mains dips - important for maintaining link availability. Low standby power from the TUHS series soft-switching design also helps meet energy-efficiency targets for always-connected equipment.
Recommended
LED Lighting Drivers
In LED luminaires and signage, the TUHS3F12 provides the 12 V control rail that drives LED-driver controllers, dimming circuitry, occupancy sensors, and wireless modules, while dedicated constant-current drivers handle the LED strings themselves. The module's universal 85 to 264 VAC input matches global lighting mains, and its encapsulated through-hole construction tolerates the elevated temperatures and restricted airflow typical of sealed luminaire housings. Because the TUHS3 design contains no aluminum or tantalum electrolytic capacitors, long-term reliability under continuous operation improves - a critical factor since lighting systems run for tens of thousands of hours. Cosel's low-noise switching technology minimizes flicker-inducing ripple on the control rail. Thermal derating must be observed when mounting near heatsink surfaces above the datasheet ambient limit.
Recommended
Test and Measurement Instrumentation
Benchtop meters, data loggers, and process instruments use the TUHS3F12 as an internal mains-to-12 V front-end that feeds further regulated analog and digital rails. The module's low-noise soft-switching design reduces ripple that would otherwise degrade high-resolution ADC measurements, and the 120 to 370 VDC input option lets instruments run from rectified DC bus architectures used in rack systems. Encapsulation shields the supply from dust and humidity in field-deployed loggers, while overcurrent protection simplifies fault handling during probe misconnection events. Designers can extend hold-up time with an external output capacitor per Cosel's application guidance, preserving measurement continuity through short mains interruptions - valuable in unattended data-acquisition installations. Verify creepage and clearance against the datasheet mechanical drawing during PCB layout.
Recommended
Security and Surveillance Systems
Camera control boards, access-control panels, and alarm hubs deployed on building mains use the TUHS3F12 for a clean 12 V rail powering microcontrollers, motor drivers for pan-tilt mechanisms, and communication modules. The universal 85 to 264 VAC input supports global installations from one PCB design, and built-in overvoltage protection guards electronics against utility transients. The encapsulated through-hole package survives outdoor-junction-box temperature swings and humidity better than open-frame alternatives, and the electrolytic-capacitor-free TUHS3 construction avoids premature aging in sealed hot enclosures. Cosel's design flexibility for hold-up time lets engineers add external capacitance so the controller records events and sends notifications through brief power dips. Always observe the datasheet derating curve for high-ambient outdoor installations.
Recommended
Recommended Products Summary
Engineering reference data for TUHS3F12 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | TUHS3F05 | TUHS3F15 | TUHS3F24 |
|---|---|---|---|---|
| Package | TUHS3F encapsulated PCB-mount through-hole | TUHS3F encapsulated PCB-mount TH - same | TUHS3F encapsulated PCB-mount TH - same | TUHS3F encapsulated PCB-mount TH - same |
| Brand | Cosel | Cosel | Cosel | Cosel |
| Output Voltage | 12 V | 5 V | 15 V | 24 V |
| Output Current | 250 mA | 600 mA | 200 mA | 125 mA |
| Output Power | 3 W | 3 W | 3 W | 3 W |
| Input Voltage Range | 85-264 VAC / 120-370 VDC | 85-264 VAC / 120-370 VDC | 85-264 VAC / 120-370 VDC | 85-264 VAC / 120-370 VDC |
| Protection Circuits | Overcurrent, Overvoltage | Overcurrent, Overvoltage | Overcurrent, Overvoltage | Overcurrent, Overvoltage |
| Electrolytic Capacitors Built-in | No | No | No | No |
| RoHS Compliance | Compliant | Compliant | Compliant | Compliant |
Key Differentiators
- No aluminum or tantalum electrolytic capacitors inside (vs Conventional encapsulated 3W AC-DC modules)
- Higher-current rail option within the same footprint (vs TUHS3F24)
- Universal AC input with DC input support (vs TUHS3F05)
Design Notes
The TUHS3F12 delivers its rated 3 W (12 V at 250 mA) only within the datasheet ambient temperature envelope; output current must be derated at higher ambients per the derating curve in the Cosel TUHS3F series datasheet. Estimate thermal margin by checking the module case temperature on the assembled board under worst-case load and ambient - encapsulated modules dissipate heat through the case into the PCB and surrounding air. Provide ventilation and avoid mounting adjacent to hot components such as bridges or Triacs. Exceeding the derating limits shortens life and may trip overcurrent protection.
Lay out the TUHS3F footprint strictly per the datasheet external-dimensions drawing, maintaining the specified creepage and clearance between the AC input pins (L/N) and the DC output pins - this isolation distance is essential for safety compliance and must not be routed under with traces or copper pours. Keep the AC input loop short, place any external hold-up/output capacitor close to the output pins, and keep noisy secondary-side switching nodes away from analog circuitry. Follow Cosel's recommended external-component values from the TUHS series datasheet.
Three pitfalls recur with 3 W AC-DC modules. First, applying DC input outside 120 to 370 VDC or AC below 85 VAC causes the output to fall out of regulation - verify the input specification for your region. Second, relying on the module's built-in overcurrent protection as a short-circuit limiter repeatedly can over-stress the unit; design the load so faults are rare and brief. Third, because the TUHS3 contains no electrolytic capacitors, hold-up time is short by default - if the system requires ride-through, add external output capacitance sized per Cosel's application guidance and verify inrush at turn-on.
Compliance Information
RoHS compliance explicitly stated in distributor listings (Lisleapex) and Cosel product pages. Other compliance attributes require confirmation from the official Cosel TUHS3F series datasheet.
