UCC28704 Off-Line Constant-Voltage Constant-Current Flyback Controller With Primary-Side Regulation (PSR) | TI.com

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 controllers

 
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 UCC28710 UCC28720 UCC28722 UCC28740 UCC28742 UCC28780
Current     Current     Current     Current     Current     Current     Current     Current     Current     Current     Current     Current    
99     100     99     100     99     99     99     99     99     99     99     99    
85     130     130     130     132     132     100     80     80     100     105     1000    
21/7.7     12.8/7.5     10.3/9.3     10.2/8     21/8.1     21/8.1     21/8     21/7.7     21/7.7     21/7.75     22/7.7     17.5/10    
PSR
DCM    
Quasi-Resonant
SSR
Green Mode
Light Load Efficiency    
SSR
Quasi-Resonant
Error Amplifier
Green Mode
Light Load Efficiency    
SSR
HV Start-up
DCM    
PSR
DCM    
PSR
DCM    
PSR
DCM
HV Start-up
Green Mode
Input Line Monitor
Leading Edge Blanking
Light Load Efficiency
Low Power
Soft Start    
PSR
DCM
HV Start-up
Current Limiting
Green Mode
HV Start-up
Input Line Monitor
Leading Edge Blanking
Light Load Efficiency
Low Power
Soft Start    
PSR
DCM    
SSR
HV Start-up
DCM    
SSR
DCM    
SSR
Zero Voltage Switching    
-40 to 125     -40 to 125     -40 to 105     -40 to 125     -20 to 125     -20 to 125     -40 to 125     -40 to 125     -40 to 125     -40 to 125     -40 to 125     -40 to 125    
SOT-23 | 6     VSSOP | 8     SOIC | 8     PDIP | 8
SOIC | 8    
SOT-23 | 6     SOT-23 | 6     SOIC | 7     SOIC | 7     SOT-23 | 6     SOIC | 7     SOT-23 | 6     SOIC | 16
WQFN | 16    
Catalog     Catalog     Catalog     Catalog     Catalog     Catalog     Catalog     Catalog     Catalog     Catalog     Catalog     Catalog    
6SOT-23: 8 mm2: 2.8 x 2.9 (SOT-23 | 6)     8VSSOP: 15 mm2: 4.9 x 3 (VSSOP | 8)     8SOIC: 29 mm2: 6 x 4.9 (SOIC | 8)     See datasheet (PDIP)
8SOIC: 29 mm2: 6 x 4.9 (SOIC | 8)    
6SOT-23: 8 mm2: 2.8 x 2.9 (SOT-23 | 6)     6SOT-23: 8 mm2: 2.8 x 2.9 (SOT-23 | 6)     7SOIC: 29 mm2: 6 x 4.9 (SOIC | 7)     7SOIC: 29 mm2: 6 x 4.9 (SOIC | 7)     6SOT-23: 8 mm2: 2.8 x 2.9 (SOT-23 | 6)     7SOIC: 29 mm2: 6 x 4.9 (SOIC | 7)     6SOT-23: 8 mm2: 2.8 x 2.9 (SOT-23 | 6)     16SOIC: 59 mm2: 6 x 9.9 (SOIC | 16)
16WQFN: 9 mm2: 3 x 3 (WQFN | 16)    

Design tool

WEBENCH® Designer UCC28704

AC Frequency  60 Hz  50 Hz
  Min   Max Range
VinRMS  V 85.0 to 2000.0V
Vout  V 3.3 to 1000V
Iout  A ≤ 100A
Ambient Temp  °C -20 to 125°C