DPA422-426
Section List
Functional Block Diagram ....................................................................................................................................... 3
Pin Functional Description ...................................................................................................................................... 3
DPA-Switch Family Functional Description ............................................................................................................ 4
CONTROL (C) Pin Operation.................................................................................................................................... 4
Oscillator and Switching Frequency.......................................................................................................................... 5
Pulse Width Modulator & Maximum Duty Cycle........................................................................................................ 5
Minimum Duty Cycle and Cycle Skipping ................................................................................................................. 6
Error Amplifier .......................................................................................................................................................... 6
On-chip Current Limit with External Programmability................................................................................................ 6
Line Undervoltage Detection (UV)............................................................................................................................. 6
Line Overvoltage Shutdown (OV).............................................................................................................................. 6
Line Feed-Forward with DCMAX Reduction ................................................................................................................ 6
Remote ON/OFF...................................................................................................................................................... 7
Synchronization........................................................................................................................................................ 7
Soft-Start................................................................................................................................................................. 8
Shutdown/Auto-Restart ........................................................................................................................................... 8
Hysteretic Over-Temperature Protection................................................................................................................... 8
Bandgap Reference ................................................................................................................................................. 8
High-Voltage Bias Current Source............................................................................................................................ 8
Using Feature Pins ..................................................................................................................................................... 8
FREQUENCY (F) Pin Operation ................................................................................................................................ 8
LINE-SENSE (L) Pin Operation ................................................................................................................................. 9
EXTERNAL CURRENT LIMIT (X) Pin Operation......................................................................................................... 9
Typical Uses of FREQUENCY (F) Pin ...................................................................................................................... 11
Typical Uses of LINE-SENSE (L) and EXTERNAL CURRENT LIMIT (X) Pins ....................................................... 11
Application Examples .............................................................................................................................................. 14
Key Application Considerations .............................................................................................................................. 16
DPA-Switch Design Considerations........................................................................................................................ 16
DPA-Switch Layout Considerations........................................................................................................................ 18
Quick Design Checklist .......................................................................................................................................... 19
Design Tools .......................................................................................................................................................... 20
Product Specifications and Test Conditions .......................................................................................................... 21
Typical Performance Characteristics .................................................................................................................. 27
Part Ordering Information ....................................................................................................................................... 30
Package Outlines .................................................................................................................................................... 31
2
Rev. T 12/12
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