UCC28720 Series

Constant-voltage, constant-current controller with primary-side regulation for bipolar power devices

Catalog(3 parts)

Part	Supplier Device Package	Frequency - Switching▲▼	Frequency - Switching▲▼	Fault Protection	Voltage - Supply (Vcc/Vdd)▲▼	Voltage - Supply (Vcc/Vdd)▲▼	Output Isolation	Operating Temperature▲▼	Operating Temperature▲▼	Topology	Mounting Type	Package / Case	Package / Case▲▼	Package / Case▲▼	Package / Case▲▼	Voltage - Start Up▲▼	Board Type	Main Purpose	Regulator Topology	Current - Output▲▼	Power - Output▲▼	Supplied Contents	Outputs and Type	Outputs and Type▲▼	Utilized IC / Part	Voltage - Output▲▼	Voltage - Input▲▼	Voltage - Input▲▼
Texas Instruments UCC28720D Converter Offline Flyback Topology 650Hz ~ 80kHz 7-SOIC	7-SOIC	80000 Hz	650 Hz	Current Limiting, Over Voltage	35 V	9 V	Isolated	125 °C	-40 °C	Flyback	Surface Mount	8-SOIC	7 ul	0.003911599982529879 m	3.900000095367432 ul	21 V
Texas Instruments UCC28720DR Converter Offline Flyback Topology 650Hz ~ 80kHz 7-SOIC	7-SOIC	80000 Hz	650 Hz	Current Limiting, Over Voltage	35 V	9 V	Isolated	125 °C	-40 °C	Flyback	Surface Mount	8-SOIC	7 ul	0.003911599982529879 m	3.900000095367432 ul	21 V
Texas Instruments UCC28720EVM-212 UCC28720 - AC/DC, Primary Side 1, Isolated Outputs Evaluation Board																	Fully Populated	AC/DC, Primary Side	Flyback	1 A	5 W	Board(s)	Isolated	1 ul	UCC28720	5 V	100 Vrms	240 Vrms

Key Features

• < 10-mW No-Load PowerPrimary-Side Regulation (PSR) Eliminates Opto-Coupler±5% Voltage and Current Regulation Across Lineand Load700-V Start-Up Switch80-kHz Maximum Switching Frequency EnablesHigh-Power Density Charger DesignsQuasi-Resonant Valley-Switching Operation forHighest Overall EfficiencyWide VDD Range Allows Small Bias CapacitorDynamic BJT DriveOvervoltage, Low-Line, and OvercurrentProtection FunctionsProgrammable Cable CompensationSOIC-7 Package< 10-mW No-Load PowerPrimary-Side Regulation (PSR) Eliminates Opto-Coupler±5% Voltage and Current Regulation Across Lineand Load700-V Start-Up Switch80-kHz Maximum Switching Frequency EnablesHigh-Power Density Charger DesignsQuasi-Resonant Valley-Switching Operation forHighest Overall EfficiencyWide VDD Range Allows Small Bias CapacitorDynamic BJT DriveOvervoltage, Low-Line, and OvercurrentProtection FunctionsProgrammable Cable CompensationSOIC-7 Package

Description

The UCC28720 flyback power supply controller provides isolated-output Constant-Voltage (CV) and Constant-Current (CC) output regulation without the use of an optical coupler. The devices process information from the primary power switch and an auxiliary flyback winding for precise control of output voltage and current. An internal 700-V start-up switch, dynamically-controlled operating states and a tailored modulation profile support ultra-low standby power without sacrificing start-up time or output transient response. Control algorithms in the UCC28720 allow operating efficiencies to meet or exceed applicable standards. The output drive interfaces to a bipolar transistor power switch. Discontinuous conduction mode (DCM) with valley switching reduces switching losses. Modulation of switching frequency and primary current peak amplitude (FM and AM) keeps the conversion efficiency high across the entire load and line ranges. The controller has a maximum switching frequency of 80 kHz and always maintains control of the peak-primary current in the transformer. Protection features help keep primary and secondary component stresses in check. The UCC28720 allows compensation for voltage drop in the cable to be programmed with an external resistor. The UCC28720 flyback power supply controller provides isolated-output Constant-Voltage (CV) and Constant-Current (CC) output regulation without the use of an optical coupler. The devices process information from the primary power switch and an auxiliary flyback winding for precise control of output voltage and current. An internal 700-V start-up switch, dynamically-controlled operating states and a tailored modulation profile support ultra-low standby power without sacrificing start-up time or output transient response. Control algorithms in the UCC28720 allow operating efficiencies to meet or exceed applicable standards. The output drive interfaces to a bipolar transistor power switch. Discontinuous conduction mode (DCM) with valley switching reduces switching losses. Modulation of switching frequency and primary current peak amplitude (FM and AM) keeps the conversion efficiency high across the entire load and line ranges. The controller has a maximum switching frequency of 80 kHz and always maintains control of the peak-primary current in the transformer. Protection features help keep primary and secondary component stresses in check. The UCC28720 allows compensation for voltage drop in the cable to be programmed with an external resistor.