VRM 9.1 DC-DC Converter Design Guidelines

Table Of Contents

VRM 9.1 DC-DC Converter Design Guidelines 3

Contents

1 Electrical Specifications......................................................................................................7

1.1 Output Requirements...........................................................................................................7

1.1.1 Voltage and Current - REQUIRED ........................................................................7

1.1.2 Maximum Ratings - EXPECTED ...........................................................................7

1.1.3 Output Voltage Tolerance - REQUIRED ...............................................................8

1.1.4 No-Load Operation - REQUIRED........................................................................12

1.1.5 Turn-on Response Time - EXPECTED ...............................................................13

1.1.6 Overshoot and Undershoot at Turn-On or Turn-Off

- REQUIRED ......................................................................................................13

1.1.7 Converter Stability - REQUIRED .........................................................................13

1.1.8 Current Sharing - REQUIRED.............................................................................13

1.2 Input Voltage and Current..................................................................................................14

1.2.1 Input Voltages - EXPECTED ...............................................................................14

1.2.2 Load Transient Effects on Input Current - EXPECTED .......................................14

1.3 Control Inputs - REQUIRED ..............................................................................................14

1.3.1 Output Enable—(OUTEN) - REQUIRED.............................................................14

1.3.2 Voltage Identification—(VID[4:0]) - REQUIRED ..................................................15

1.4 Remote Sense (VO-sen+, VO-sen–) - EXPECTED...........................................................15

1.5 Power Good Output (PWRGD) - REQUIRED....................................................................16

1.5.1 Power Good Threshold Voltages - EXPECTED..................................................16

1.5.2 Power Good Operation - EXPECTED .................................................................16

1.6 VRM Present (VRM-pres) - EXPECTED ...........................................................................16

1.7 Efficiency - PROPOSED....................................................................................................16

1.8 Isolation - PROPOSED ......................................................................................................17

1.9 Fault Protection..................................................................................................................17

1.9.1 Over Voltage Protection - EXPECTED................................................................17

1.9.2 Fuse Protection for Power Input - EXPECTED ...................................................17

1.9.3 Overload Protection - EXPECTED ......................................................................17

1.9.4 Reset After Shutdown - PROPOSED..................................................................18

2 Module Layout Guidelines................................................................................................19

2.1 VRM Connector - EXPECTED...........................................................................................19

2.2 Mechanical Dimensions - PROPOSED .............................................................................20

3 Environmental Conditions ................................................................................................23

3.1 Operating Temperature - PROPOSED ..............................................................................23

3.2 VRM Board Temperature - REQUIRED.............................................................................23

3.3 Non-Operating Temperature - PROPOSED ......................................................................23

3.4 Humidity - PROPOSED .....................................................................................................23

3.5 Altitude - PROPOSED .......................................................................................................24

3.6 Electrostatic Discharge - PROPOSED...............................................................................24

3.7 Shock and Vibration - PROPOSED ...................................................................................24

3.8 Electromagnetic Compatibility - PROPOSED ....................................................................24

3.9 Reliability - PROPOSED ....................................................................................................24

3.10 Safety - PROPOSED .........................................................................................................24