UCC28722 Datasheet, PDF (1/34 Pages) Texas Instruments – Constant-Voltage, Constant-Current Controller

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UCC28722
SLUSBL7B – DECEMBER 2013 – REVISED OCTOBER 2015
UCC28722 Constant-Voltage, Constant-Current Controller
With Primary-Side Regulation, BJT Drive
1 Features
•1 < 50-mW No-Load Power
• Primary-Side Regulation (PSR) Eliminates Opto-
Coupler
• Dynamic BJT Drive
• ± 5% Voltage and Current Regulation Across Line
and Load
• 80-kHz Maximum Switching Frequency Enables
High-Power Density Charger Designs
• Quasi-Resonant Valley-Switching Operation for
Highest Overall Efficiency
• Wide VDD Range Allows Small Bias Capacitor
• Output Overvoltage, Low-Line, and Overcurrent
Protection Functions
• Programmable Cable Compensation
• SOT23-6 Package
2 Applications
• USB-Compliant Adapters and Chargers for
Consumer Electronics
– Smart Phones
– Tablet Computers
– Cameras
• Standby Supply for TVs and Desktops
• White Goods
3 Description
The UCC28722 flyback power supply controller
provides isolated-output constant-voltage (CV) and
constant-current (CC) output regulation without the
use of an optical coupler. The device processes
information from the primary power switch and an
auxiliary flyback winding for precise control of output
voltage and current.
Dynamically-controlled operating states and a tailored
modulation profile support high-efficiency operation at
all load levels without sacrificing output transient
response.
Control algorithms in the UCC28722 device allow
operating efficiencies to meet or exceed applicable
standards. The output drive interfaces to a bipolar
transistor power switch, enabling lower-cost converter
design. Discontinuous conduction mode (DCM) with
valley switching reduces switching losses, while
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. Output overvoltage
and overcurrent as well as input undervoltage
protection features help keep primary and secondary
component stresses in check. The UCC28722 also
allows compensation for voltage drop in the cable to
be programmed with an external resistor.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
UCC28722
DBV (6)
2.90 mm × 1.60 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Simplified Application Diagram
Np
Ns
VOUT
VIN
UCC28722
Na
1 CBC
VS 6
2 VDD
GND 5
3 DRV
CS 4
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.