Texas Instruments UCC28517, Руководство пользователя

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SLUU117C − September 2002 − Revised July 2003
4 UCC28517 EVM
UCC28517 EVM
Michael O’Loughlin Power Supply Control Products
Contents
1 Introduction 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Caution 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Schematic 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 List of Materials 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 Reference Design Layout 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 Electrical Characteristics 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7 Reference Design Performance 11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 Introduction
The UCC28517 module is a 100-W offline ac-to-dc voltage converter with power factor correction (PFC). The
prototype was designed to show how the UCC28517 could be configured to control two dc-regulated outputs
offline with one control integrated circuit. The module was design to operate over a universal input range of 85
V to 265 V with two dc regulated outputs. Output B is a 12-V, 8-W regulated output intended to be used as a
bias supply and output A is a 385-V, 100-W regulated output.
For this module to function correctly output B needs a minimum load of 4 W and boost capacitor C3 needs to
be completely discharged before applying power. The input needs a minimum of 85 V
AC
at power up. If the input
voltage is brought up slowly with the use of an ac source or a variable transformer the bootstrap circuitry will
not function correctly. If this procedure is not followed the reference design will not regulate properly.
2 Caution
High-voltage levels are present on the evaluation module whenever it is energized. Proper precautions must
be taken when working with the module. Output A has a large energy storage capacitor and must be completely
discharged before the module can be handled. Serious injury can occur if proper safety precautions are not
followed.