Filter
Top Products
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
4
Contents
1 Introduction .....................................................................................................7
1.1 TFX12V Scope............................................................................................................ 7
1.2 TFX12V Overview ....................................................................................................... 7
1.2.1 Small System Optimized Profile .................................................................... 7
1.2.2 Improved Acoustics....................................................................................... 8
1.3 Key Changes for TFX12V Version 2.0......................................................................... 8
1.3.1 Increased +12 VDC Output Capability........................................................... 8
1.3.2 Minimum Efficiency ....................................................................................... 8
1.3.3 Main Power Connector.................................................................................. 8
1.3.4 Separate Current Limit for 12V2 on the 2x2 Connector................................. 8
1.4 Terminology................................................................................................................. 9
2 Electrical ........................................................................................................10
2.1 AC Input 10
2.1.1 Input Over Current Protection ......................................................................10
2.1.2 Inrush Current Limiting.................................................................................10
2.1.3 Input Under Voltage .....................................................................................10
2.1.4 Regulatory....................................................................................................11
2.1.5 Catastrophic Failure Protection ....................................................................12
2.2 DC Output ..................................................................................................................12
2.2.1 DC Voltage Regulation.................................................................................12
2.2.2 Remote Sensing...........................................................................................12
2.2.3 Typical Power Distribution............................................................................13
2.2.4 Power Limit / Hazardous Energy Levels.......................................................16
2.2.5 Efficiency General........................................................................................16
2.2.6 Other Low Power System Requirements......................................................18
2.2.7 Output Ripple/Noise .....................................................................................18
2.2.8 Output Transient Response .........................................................................19
2.2.9 Capacitive Load ...........................................................................................20
2.2.10 Closed-loop Stability.....................................................................................20
2.2.11 +5 VDC / +3.3 VDC Power Sequencing .......................................................20
2.2.12 Voltage Hold-up Time...................................................................................20
2.3 Timing / Housekeeping / Control.................................................................................21
2.3.1 PWR_OK .....................................................................................................22
2.3.2 PS_ON#.......................................................................................................22
2.3.3 +5 VSB.........................................................................................................23
2.3.4 Power-on Time.............................................................................................23
2.3.5 Rise Time.....................................................................................................24
2.3.6 Overshoot at Turn-on / Turn-off....................................................................24
2.3.7 Reset after Shutdown...................................................................................24
2.3.8 +5 VSB at AC Power-down ..........................................................................24
2.4 Output Protection .......................................................................................................24
2.4.1 Over Voltage Protection ...............................................................................24
2.4.2 Short-circuit Protection.................................................................................25