UCC28782CDRTWR Texas Instruments Integrated Circuit (Quad Flat No-Lead) In Stock
The UCC28782CDRTWR is a high-density active clamp flyback (ACF) controller IC from Texas Instruments, featuring current-mode PWM control, integrated EMI frequency dithering, X-capacitor discharge, and bias power management for compact USB-PD and AC-DC adapter designs. Key specs: 14V to 34V VCC input range, current-mode control, 24-pin QFN package, YTEOL 15 years. Available RoHS-compliant in tape-and-reel from authorized distributors in stock with worldwide shipping.
- Manufacturer
- Texas Instruments
- Package
- Quad Flat No-Lead
- Pin Count
- 25
- Lifecycle
- ACTIVE
- Datasheet
- UCC28782CDRTWR Datasheet PDF
- Category
- Integrated Circuit
- Temp Range
- -40.0°C to 125.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- Active clamp flyback (ACF) topology control achieves high conversion efficiency by recovering transformer leakage energy through the clamp switch, enabling compact adapters with reduced heat sink requirements compared to conventional flyback designs
- Integrated EMI frequency dithering spreads switching noise across a wider spectrum, reducing peak EMI emissions and simplifying compliance with CISPR 32 and FCC Part 15 Class B requirements without bulky EMI filters
- X-capacitor automatic discharge function safely discharges mains X-capacitors after power removal, meeting IEC 62368-1 safety requirements without external resistor discharge circuits that waste standby power
- Bias power management with wide 14V to 34V VCC range supports direct bias winding supply across varying line and load conditions, reducing the need for additional LDO regulators in the auxiliary power path
Applications
The UCC28782CDRTWR is specifically designed for high-density USB Power Delivery (USB-PD) chargers, GaN-based AC-DC adapters, and laptop power bricks where minimizing adapter size and maximizing efficiency across the full load range are primary design goals. The active clamp flyback topology it controls enables soft-switching operation that dramatically reduces switching losses at high frequencies above 200kHz, enabling the miniaturized form factors demanded by modern 45W to 100W consumer power adapters. It also serves industrial 24V and 48V power supplies requiring high efficiency, low standby power, and built-in safety features for compliance with energy efficiency standards like DoE Level VI and ErP Lot 6.
Specifications
| Pbfree Code | Yes |
| YTEOL | 15 |
| Analog IC - Other Type | SWITCHING CONTROLLER |
| Control Mode | CURRENT-MODE |
| Control Technique | PULSE WIDTH MODULATION |
| Input Voltage-Max | 34V |
| Input Voltage-Min | 14V |
| Input Voltage-Nom | 20V |
| JESD-30 Code | S-PQCC-N24 |
| JESD-609 Code | e4 |
| Number of Functions | 1 |
| Output Current-Max | 0.4525A |
| Package Body Material | PLASTIC/EPOXY |
| Package Equivalence Code | LCC24,.16SQ,20 |
| Package Shape | SQUARE |
| Package Style | CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE |
| Peak Reflow Temperature (Cel) | 260 |
| Supply Current-Max (Isup) | 3.55mA |
| Supply Voltage-Nom (Vsup) | 20V |
| Surface Mount | YES |
| Switcher Configuration | BUCK-BOOST |
| Switching Frequency-Max | 1500kHz |
| Terminal Finish | Nickel/Palladium/Gold (Ni/Pd/Au) |
| Terminal Form | NO LEAD |
| Terminal Pitch | 0.5mm |
| Terminal Position | QUAD |
| Time@Peak Reflow Temperature-Max (s) | 30 |
| Package | Quad Flat No-Lead |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| Moisture Sensitivity Level | MSL 1 |
| ECCN | EAR99 |
| HTS Code | 8542.39.00.90 |
Alternate & Equivalent Parts
Compatible alternatives and drop-in replacements for UCC28782CDRTWR:
Switching Controller, Current-mode, 0.4525A, 1500kHz Switching Freq-Max, PQCC24
Switching Controller, Current-mode, 0.4525A, 1500kHz Switching Freq-Max, PQCC24
Frequently Asked Questions
What power topology does the UCC28782CDRTWR control?
The UCC28782CDRTWR controls an active clamp flyback (ACF) converter topology, which adds an active clamp switch and capacitor across the primary winding to recycle transformer leakage inductance energy that conventional flyback designs dissipate as heat. This enables zero-voltage switching (ZVS) of the main switch at high frequencies, significantly reducing switching losses and enabling power densities and efficiencies not achievable with quasi-resonant or hard-switched flyback controllers.
What is the VCC input voltage range of the UCC28782CDRTWR?
The UCC28782CDRTWR VCC supply range is 14V minimum to 34V maximum with a nominal 20V operating point. This wide range allows the IC to be powered directly from a transformer bias winding that varies with input line voltage and output load, accommodating both 90VAC and 265VAC universal input conditions in AC-DC converter designs without requiring a separate regulated bias supply.
What is the X-capacitor discharge function in the UCC28782CDRTWR?
The X-capacitor automatic discharge function safely discharges X-capacitors connected across the mains input within the time limit specified by IEC 62368-1 safety standards (typically under 1 second after power removal). Conventional solutions use bleed resistors which continuously dissipate power during normal operation. The UCC28782CDRTWR activates discharge only when needed, eliminating standby power waste while meeting regulatory safety requirements for accessible connector voltage after disconnection.
What package does the UCC28782CDRTWR come in?
The UCC28782CDRTWR is housed in a 24-pin VQFN (Very Thin Quad Flat No-Lead) square package with JESD-30 code S-PQCC-N24. The QFN package offers a compact footprint with an exposed thermal pad for heat dissipation. The TWR suffix indicates tape-and-reel packaging for automated pick-and-place assembly in volume production environments.
How does the EMI dithering feature benefit power supply designs?
The integrated EMI frequency dithering in the UCC28782CDRTWR modulates the switching frequency slightly around its nominal value, spreading the switching harmonics across a wider frequency band. This reduces peak emission levels at any single frequency point, making it easier to pass conducted and radiated EMI tests per CISPR 32 and FCC Part 15 standards. Dithering can reduce peak EMI by 6-10dB, allowing designers to reduce or eliminate common-mode chokes and other bulky EMI suppression components.
Related Guides
TPS61291DRVR Selection Guide: Low-Quiescent-Current Boost Converters for IoT and Wearables
How to select the TPS61291DRVR and low-Iq boost converters for IoT, wearables, and coin-cell designs. Compares specs, packages, and alternatives from TI, ADI, and Microchip.
May 13, 2026
TMS5704357BZWTQQ1 Selection Guide: Choosing the Right TMS570 Automotive MCU Variant
Compare TMS570 automotive MCU variants by ASIL level, flash, package, and peripherals. Find the right fit from entry-level LQFP to the ASIL-D TMS5704357BZWTQQ1.
May 13, 2026
TI Hercules TMS5704357BZWTQQ1 Design Guide for Automotive ASIL-D and Industrial Functional Safety
Complete integration guide for the TI Hercules TMS5704357BZWTQQ1 dual-core lockstep Cortex-R5F MCU: lockstep CPU, ECC RAM, FlexRay/CAN-FD, and ASIL-D pitfalls.
May 12, 2026
PTN78000WAH Selection Guide: Choosing the Right 1.5 A 36 V Step-Down Power Module
Compare PTN78000WAH against PTN78000WAS, PTN78060WAH, and other 1.5A 36V step-down modules. Covers package, current rating, efficiency, and drop-in replaceability.
May 12, 2026
Why Buy from FindMyChip
About Texas Instruments
Texas Instruments (TI) is a global semiconductor company headquartered in Dallas, Texas. TI designs and manufactures analog and embedded processing chips used in industrial, automotive, consumer, communications, and enterprise systems.
More from Texas Instruments
ULN2003ANE4
Dual-In-Line Packages
Integrated Circuit
OPA2381AIDGKT
Small Outline Packages
Integrated Circuit
CD54HCT75F3A
Ceramic Dual-In-Line Packages
Integrated Circuit
SN65HVD1786D
Small Outline Packages
Integrated Circuit
ULN2003BPWR
Small Outline Packages
Integrated Circuit
ULN2003APWR
Small Outline Packages
Integrated Circuit
In Stock · 24h Response · Worldwide Shipping
Response within 24 hours · Worldwide shipping
“FindMyChip sourced our entire STM32 BOM in 48 hours when our usual distributor had 16-week lead times.”