TI’s UCC28810 and UCC28811 are general lighting power supply controllers that can control flyback, buck or boost converters in critical conduction mode, integrated transconductance voltage amplifiers for feedback error handling, reference current generators, current Detection (PWM) comparator, PWM logic and totem pole driver to drive external FETs. Mainly used in HB LED lighting, industrial, commercial and residential lighting and outdoor lighting. This article introduces the main features of the UCC28810/1, block diagram, simplified Application circuit diagram and 110W offline AC/DC LED driver UCC28810EVM-003 main features, circuit diagram, bill of materials and PCB layout.
The UCC28810 and UCC28811 are general lighting power controllers for low to medium power lumens applications requiring power factor correction and EMC compliance. It is designed for controlling a flyback, buck or boost converter operating in critical conduction mode. It features a transconductance voltage amplifier for feedback error processing, a simple current reference generator for generating a current command proportional to the input voltage, a current-sense (PWM) comparator, PWM logic and a totem-pole driver for driving an external FET.
In the critical conduction mode operation, the PWM circuit is self-oscillating with the turn-on being governed by a transformer zero energy detector (TZE pin) and the turn-off being governed by the current sense comparator.
Main features of UCC28810/1:
Transition Mode Controller for Low Implementation Cost of AC Input LED Lighting Applications
Implements Single Stage Power Factor Corrected LED Driver
Enhanced Transient Response With Slew-Rate Comparator
Interfaces with Traditional Wall Dimmers
Accurate Internal VREF for Tight Output Regulation
Two UVLO Options
Overvoltage Protection (OVP), Open-Feedback Protection and Enable Circuits
±750-mA Peak Gate Drive Current
Low Start-Up and Operating Currents
Lead (Pb)-Free Packages
AC Input General Lighting Applications Using HB LEDs
Industrial, Commercial and Residential Lighting Fixtures
Outdoor Lighting: Street, Roadway, Parking, Construction and Ornamental LED Lighting Fixtures
Figure 1. UCC28810/1 Block Diagram
Figure 2. UCC28810/1 Simplified Application Circuit Diagram
110W Offline AC/DC LED Driver UCC28810EVM-003
The UCC28810EVM-003 is an 110-W offline AC-to-DC LED current driver with power factor correction. This design utilizes a three stage approach with a universal input boost PFC stage, a low-side buck stage providing a controlled current source and a half-bridge DC transformer stage to provide isolation to four LED strings.
This converter was designed to support up to four strings of 15 high brightness LED’s in series (58.5 V max per string). The converter will provide 500-mA average current to each string. The design incorporates an interface for microprocessor control to allow for shutdown into a low power mode (<0.5 W) and PWM dimming of the LED's.
The boost, buck and DC half bridge multi-transformer stages are included on a UCC28810EVM-003 single board assembly.
Main features of UCC28810EVM-003:
90-VRMS to 265-VRMS Operation
Boost Follower or Fixed Output PFC Stage
Output Current Disable
External or Internal PWM Dimming
Output Isolated from Line Input
Open Circuit Protection (If one LED string fails open the remaining strings stay on.)
Typical applications of UCC28810EVM-003:
• AC Input General Lighting Applications Using HB LEDs
• Industrial, Commercial and Residential Lighting Fixtures
• Outdoor Lighting: Street, Roadway, Parking, Construction and Ornamental LED Lighting Fixtures
• LCD TV LED Backlighting
Figure 3. UCC28810EVM-003 Outline Drawing
Figure 4. UCC28810EVM-003 board assembly diagram
UCC28810EVM-003 electrical performance indicators:
Figure 5. UCC28810EVM-003 PFC stage circuit diagram
Figure 6. UCC28810EVM-003 Buck Stage Circuit Diagram
Figure 7. UCC28810EVM-003 DC Transformer Circuit Diagram
UCC28810EVM-003 Bill of Materials:
Figure 8. UCC28810EVM-003 PCB layout (top: top component layout, middle: top copper routing, bottom: bottom copper routing)
For details, see: