E910.27A View Datasheet(PDF) - ELMOS Semiconductor AG

Part Name

Description

MFG CO.

E910.27A

External Adjustable High Efficiency PFM Step-Down Converter

ELMOS Semiconductor AG 

Prev 41 42 43 44 45 46 47 48 49 50

- Preliminary -

E910.27A

14 Index

Table of Content

1 General...........................................................................................................................................................2

1.1 WARNING – Life Support Applications Policy.......................................................................................2

1.2 General Disclaimer................................................................................................................................2

1.3 Application Disclaimer............................................................................................................................2

1.4 Contact...................................................................................................................................................2

2 Pinout.............................................................................................................................................................3

2.1 Pin Description.......................................................................................................................................3

2.2 Package Pinout......................................................................................................................................5

3 Basic Blockdiagram........................................................................................................................................6

4 Operating Conditions.....................................................................................................................................7

4.1 Absolute Maximum Ratings...................................................................................................................7

4.2 Recommended Operating Conditions...................................................................................................9

5 Detailed Electrical Characteristics...............................................................................................................10

5.1 Supply Voltage and Currents...............................................................................................................10

5.2 Low Drop Internal Voltage Regulator...................................................................................................10

5.3 Internal VSM Undervoltage Lockout Level..........................................................................................10

5.4 MUX.....................................................................................................................................................11

5.5 Voltage Comparator.............................................................................................................................11

5.6 Current Comparator.............................................................................................................................11

5.7 Pulse Frequency Modulator.................................................................................................................12

5.8 Power Stage.........................................................................................................................................12

5.9 Error Output and Optional Short Detection Delay Input......................................................................12

5.10 Power Good / Reset and Watchdog Stage........................................................................................12

5.11 Thermal Shutdown.............................................................................................................................13

6 Typical Performance Characteristics...........................................................................................................14

7 Functional Description..................................................................................................................................16

7.1 Operation.............................................................................................................................................16

7.1.1 Typical Application Circuit............................................................................................................16

7.1.2 Introduction..................................................................................................................................16

7.2 Linear Regulators.................................................................................................................................17

7.2.1 Internal Power Supply..................................................................................................................17

7.2.2 VSM Regulator.............................................................................................................................17

7.3 Device Quiscent Currents....................................................................................................................17

7.4 DRV Regulator.....................................................................................................................................17

7.5 Error Output.........................................................................................................................................17

7.6 Reference Multiplexer..........................................................................................................................18

7.7 Power Good, Reset Generation and Watchdog Circuitry....................................................................18

7.7.1 PWRGOOD Block........................................................................................................................18

7.7.2 Power Good and Reset Timing...................................................................................................18

7.7.3 Watchdog Timing.........................................................................................................................20

7.8 Description of the SMPS Section.........................................................................................................21

7.8.1 Operating Modes.........................................................................................................................22

7.8.2 100% Duty Cycle and Dropout....................................................................................................22

7.8.3 Discontinuous Conduction Mode.................................................................................................22

ELMOS Semiconductor AG

Specification 48 / 50

03SP0357E.00 05.09.2006

Share Link: