Texas Instruments UCC28056 High Performance PFC Controllers

Texas Instruments UCC28056 6-Pin High-Performance PFC Controllers offer an innovative mixed-mode method derived from the devices’ PFC boost stages. The mixed-mode method operates in Transition Mode (TM) at full load and transitions smoothly into Discontinuous Conduction Mode (DCM) at a reduced load, resulting in an automatically decreasing switching frequency. The device includes burst mode operation eliminating the need to switch off the PFC, improving light load performance, and allowing systems to meet demanding energy standards. The Texas Instruments UCC28056 ensures sinusoidal line input current with low distortion while the PFC stays on via the PFC power stage, driving power to 300W. Combined with the UCC256301 LLC controller, the need for an auxiliary flyback converter is eliminated. The UCC28056 provides an instant turn-on feature and minimizes the external component count.

Features

Low input current distortion and near unity power factor down to 10% load
- Enables compliance with IEC1000-3-2
Ultra-low no-load input power (25mW at 115V_AC, 40mW at 230V_AC)
Excellent efficiency over the range of load
Enables compliance with green power standards without disabling PFC
- EuP Lot 6 Tier 2, CoC Ver. 5 Tier 2, Energy Star for computers Ver. 6.1, DOE Level VI
Ultra-low audible noise output

Enhanced EA responds rapidly to load steps without degrading input current distortion
Valley synchronized turn-on requires no second winding on the boost inductor
User-adjustable valley delay
Low start-up current consumption (<46µA)
Wide V_CC range 8.5V to 34V
Cycle-by-cycle current limit
Burst mode with soft-entry and soft-exit periods
Second independent output voltage protection
Integrated over-temperature protection