UCC28704 (ACTIVE)

Off-Line Constant-Voltage Constant-Current Flyback Controller With Primary-Side Regulation (PSR)

 

Description

The UCC28704 Off-line flyback controller is a highly integrated, 6-pin primary-side regulated PWM controller for designing high efficiency AC-to-DC power supplies with low standby power consumption to comply with global efficiency standards. The controller has ultra-low current consumption at start-up to enable designs with <30-mW no-load input power and save standby mode energy consumption. Intelligent primary-side sensing and control enables 5% output voltage and current control without using an opto coupler or secondary-side feedback circuits.

UCC28704 incorporates an enhanced load transient response technique which helps minimize the output capacitor, reducing the overall system size and cost. The controller also eliminates the need for loop compensation components which simplify the design and debugging process for power supply designers. The converter output voltage and current is regulated to prevent overstress conditions that may damage the load or connectors. Similarly, the CCUV shutdown feature monitors for an output under voltage fault to protect connectors from over heat or burn out from soft shorts, which greatly enhance overall system reliability. Board or component over temperature protection is facilitated with an NTC interface pin.

UCC28704 can be readily used with TI secondary-side synchronous rectifier (SR) controllers at 2-A or higher output current levels for higher conversion efficiency or more compact designs.

For all available packages, see the orderable addendum at the end of the datasheet.

Features

  • Efficiency Performance Exceeds DoE Level VI and EU CoC V5 Tier-2 External Power Supply Standards
  • Primary-Side Regulation Eliminates Opto-Coupler and Secondary Feedback Components
  • Compatible with Synchronous Rectifier
  • Enables <30-mW No-Load Input Power
  • ±5% Output Voltage (CV) and Current (CC) Regulation
  • Enhanced Dynamic Load Response
  • Constant Current Output Under-Voltage Protection (CCUV) with Auto-Restart Response
  • Cable Compensation (300 mV at 5-V Full Load)
  • 85-kHz Maximum Switching Frequency
  • DCM Valley-Switching Operation
  • Clamped Gate-Drive Output for MOSFET
  • NTC Resistor Interface
  • Resistor or External HV Depletion-Mode FET Start-Up
  • Fault Protections: Input Low Line, Output Over-Voltage, Over-Current, and Short-Circuit
  • SOT23-6 Package

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Parametrics Compare all products in Flyback Controller

 
Control Method
Duty Cycle (Max) (%)
Frequency (Max) (kHz)
UVLO Thresholds On/Off (V)
Features
Operating Temperature Range (C)
Package Group
Rating
Package Size: mm2:W x L (PKG)
UCC28704 LM5023 UCC28600 UCC28610 UCC28700 UCC28703 UCC28740 UCC28780
Current    Current    Current    Current    Current    Current    Current    Current   
99    100    99    100    99    99    99    99   
85    130    130    130    132    132    100    1000   
21/7.7    12.8/7.5    10.3/9.3    10.2/8    21/8.1    21/8.1    21/7.75    17.5/10   
PSR
HV Start-up Configurable
Fixed CBC
NTC Configurable
CV/CC Control
DCM
USB Type-C Compatible
IoT Compatible
Power Delivery Compatible   
SSR
HV Start-up Configurable
QR/TM
Green Mode
Light Load Efficiency
Power Delivery Compatible   
SSR
QR/TM
Error Amplifier
Green Mode
Light Load Efficiency
Power Delivery Compatible
Motor Drive Compatible
Audio Compatible   
DCM
SSR
HV Start-up
Soft Switching
Power Delivery Compatible
Audio Compatible
Motor Drive Compatible   
PSR
Adjustable CBC
CV/CC Control
DCM
Power Delivery Compatible   
PSR
Fixed CBC
NTC Configurable
CV/CC Control
DCM   
SSR
HV Start-up
CV/CC Control
DCM
Smart Meters Compatible
IoT Compatible
USB Type-C Compatible
Power Delivery Compatible   
Zero Voltage Switching
Active Clamp Flyback   
-40 to 125    -40 to 125    -40 to 105    -40 to 125    -20 to 125    -20 to 125    -40 to 125    -40 to 125   
SOT-23    VSSOP    SOIC    PDIP
SOIC   
SOT-23    SOT-23    SOIC    SOIC
WQFN   
Catalog    Catalog    Catalog    Catalog    Catalog    Catalog    Catalog    Catalog   
6SOT-23: 8 mm2: 2.8 x 2.9(SOT-23)    8VSSOP: 15 mm2: 4.9 x 3(VSSOP)    8SOIC: 29 mm2: 6 x 4.9(SOIC)    See datasheet (PDIP)
8SOIC: 29 mm2: 6 x 4.9(SOIC)   
6SOT-23: 8 mm2: 2.8 x 2.9(SOT-23)    6SOT-23: 8 mm2: 2.8 x 2.9(SOT-23)    7SOIC: 29 mm2: 6 x 4.9(SOIC)    16SOIC: 59 mm2: 6 x 9.9(SOIC)
16WQFN: 9 mm2: 3 x 3(WQFN)   

WEBENCH® Designer UCC28704

AC Frequency  60 Hz  50 Hz
  Min   Max Range
VinRMS  V 85.0 to 480.0V
Vout  V 3.3 to 25.0V
Iout  A ≤ 10A
Ambient Temp  °C -40 to 125°C