UCC28700 Datasheet, PDF (1/30 Pages) Texas Instruments – Constant-Voltage, Constant-Current Controller With Primary-Side Regulation

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UCC28700, UCC28701
UCC28702, UCC28703
SLUSB41 – JULY 2012
Constant-Voltage, Constant-Current Controller
With Primary-Side Regulation
Check for Samples: UCC28700, UCC28701, UCC28702, UCC28703
FEATURES
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• < 30-mW No-Load Power for 5-Star Rating
• Primary-Side Regulation (PSR) Eliminates
Opto-Coupler
• ±5% Voltage and Current Regulation
• 130-kHz Maximum Switching Frequency
Enables High-Power Density Charger Designs
• Quasi-Resonant Valley-Switching Operation
for Highest Overall Efficiency
• Patent-Pending Frequency-Jitter Scheme to
Ease EMI Compliance
• Wide VDD Range Allows Small Bias Capacitor
• Clamped Gate-Drive Output for MOSFET
• Protection Functions: Over-Voltage, Low-Line,
and Over-Current
• Programmable Cable Compensation
(UCC28700 only)
• NTC Resistor Interface (UCC28701, UCC28702
and UCC28703 only) with Fixed Cable
Compensation Options
• SOT23-6 Package
APPLICATIONS
• USB-Compliant Adapters and Chargers for
Consumer Electronics (cell phones, tablets
and cameras)
• AC and DC Power Supplies
DESCRIPTION
The UCC28700 family of flyback power supply
controllers provides 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. Low start-up current,
dynamically-controlled operating states and a tailored
modulation profile support very low stand-by power
without sacrificing start-up time or output transient
response.
Control algorithms in the UCC28700 family allow
operating efficiencies to meet or exceed applicable
standards. The output drive interfaces to a MOSFET
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 controllers have a maximum switching frequency
of 130 kHz and always maintain control of the peak-
primary current in the transformer. Protection features
help keep primary and secondary component
stresses in check. The UCC28700 allows the level of
cable compensation to be programmed. The
UCC28701, UCC28702 and UCC28703 devices allow
remote temperature sensing using a Negative
Temperature Coefficient (NTC) resistor while
providing fixed cable-compensation levels.
Simplified Application Diagram and Typical V-I Regulation
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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2012, Texas Instruments Incorporated