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User

'

s Guide

SLVU455

April 2011

TPS62730 Stepdown Converter With Bypass Mode for

Ultralow-Power Wireless Applications

This user

s guide describes the TPS62730 evaluation module (EVM), how to perform a stand-alone

evaluation or interface with a host or system. The converter is designed to deliver up to 100 mA of
continuous current to the output. The converter can be switched into bypass mode by grounding the
ON/BYP pin or automatically with the input voltage falling to the output regulation voltage.

Contents

1

Introduction

..................................................................................................................

2

2

Considerations With Evaluating the TPS62730

.........................................................................

2

3

Performance Specification Summary

.....................................................................................

2

4

Test Summary

...............................................................................................................

2

4.1

Equipment

...........................................................................................................

3

4.2

Equipment and EVM Setup

.......................................................................................

3

4.3

Test Procedure Using a Single Cell Li-Ion Battery

............................................................

4

5

Schematic, Physical Layouts and Bill of Materials

.....................................................................

5

5.1

Schematic

...........................................................................................................

5

5.2

Physical Layouts

...................................................................................................

5

5.3

Bill of Materials

.....................................................................................................

7

6

Oscilloscope Traces

........................................................................................................

7

List of Figures

1

EVM Schematic and Evaluation Setup

...................................................................................

3

2

TPS62730 EVM Board Schematic

........................................................................................

5

3

Assembly Layer

.............................................................................................................

5

4

Top Layer

....................................................................................................................

6

5

Bottom Layer

................................................................................................................

6

6

CH1: Phase; CH2: Output Ripple, Vin = 3.3 V, and 21-

Ω

Load

......................................................

7

7

PFM Mode at Low Load, 40 mA

CH1: Phase; CH2: Output Ripple; 0.2

µ

s/div

..................................

8

8

PFM Mode at Low Load, 11 mA

CH1: Phase; CH2: Output Ripple; 1

µ

s/div

....................................

8

9

Transition From Switching Converter to Bypass Mode by Removing Input Power

CH1: Phase Node;

CH2: STAT Pin

..............................................................................................................

9

10

Transition From Converter Switch Mode to Bypass Mode by Pulling ON/BYP Pin Low

..........................

9

11

Transition From Bypass Mode to Converter Switch Mode by Pulling ON/BYP Pin High

........................

10

12

Startup by Hot-Plugging the Input Power Source

.....................................................................

10

13

Transient Output Load Step From 50 mA to 100 mA

.................................................................

11

14

Transient Output Load Step From 100 mA to 50 mA

.................................................................

11

1

SLVU455

April 2011

TPS62730 Stepdown Converter With Bypass Mode for Ultralow-Power Wireless

Applications

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Copyright

©

2011, Texas Instruments Incorporated

Summary of Contents for TPS62730

Page 1: ...l Layouts 5 5 3 Bill of Materials 7 6 Oscilloscope Traces 7 List of Figures 1 EVM Schematic and Evaluation Setup 3 2 TPS62730 EVM Board Schematic 5 3 Assembly Layer 5 4 Top Layer 6 5 Bottom Layer 6 6...

Page 2: ...IC will be in an unknown state mode and the output voltage could be anywhere between the input voltage and the regulation voltage The EVM has a pullup resistor on the ON BYP pin to Vin so that it stay...

Page 3: ...d of DMM 2 J5 2 SNS output Negative lead of DMM 2 J6 1 2 GND Negative lead to system load or load resistance J7 1 STAT Positive lead of DMM meter 3 J7 2 GND Negative lead of DMM meter 3 JP1 1 2 ON App...

Page 4: ...may be required depending on power supply decay single sequence trigger on CH2 and removing input power The phase node is shown going into PFM then disabling switching and then indicating bypass mode...

Page 5: ...nd Bill of Materials 5 1 Schematic Figure 2 TPS62730 EVM Board Schematic 5 2 Physical Layouts Figure 3 Assembly Layer 5 SLVU455 April 2011 TPS62730 Stepdown Converter With Bypass Mode for Ultralow Pow...

Page 6: ...f Materials www ti com Figure 4 Top Layer Figure 5 Bottom Layer 6 TPS62730 Stepdown Converter With Bypass Mode for Ultralow Power Wireless SLVU455 April 2011 Applications Submit Documentation Feedback...

Page 7: ...g 0 100 inch 2 54 mm 3 PEC02SAAN Sullins 1 L1 2 2 H Inductor SMT 0 8 A 0 23 0805 LQM21PN2R2NGC muRata 1 R1 10 0 k Resistor chip 1 16W 1 0603 Std Std 1 R2 1 00 M Resistor chip 1 16W 1 0603 Std Std 1 U1...

Page 8: ...e CH2 Output Ripple 0 2 s div Figure 8 PFM Mode at Low Load 11 mA CH1 Phase CH2 Output Ripple 1 s div 8 TPS62730 Stepdown Converter With Bypass Mode for Ultralow Power Wireless SLVU455 April 2011 Appl...

Page 9: ...Input Power CH1 Phase Node CH2 STAT Pin Figure 10 Transition From Converter Switch Mode to Bypass Mode by Pulling ON BYP Pin Low 9 SLVU455 April 2011 TPS62730 Stepdown Converter With Bypass Mode for...

Page 10: ...erter Switch Mode by Pulling ON BYP Pin High Figure 12 Startup by Hot Plugging the Input Power Source 10 TPS62730 Stepdown Converter With Bypass Mode for Ultralow Power Wireless SLVU455 April 2011 App...

Page 11: ...ad Step From 50 mA to 100 mA Figure 14 Transient Output Load Step From 100 mA to 50 mA 11 SLVU455 April 2011 TPS62730 Stepdown Converter With Bypass Mode for Ultralow Power Wireless Applications Submi...

Page 12: ...ct This notice contains important safety information about temperatures and voltages For additional information on TI s environmental and or safety programs please contact the TI application engineer...

Page 13: ...orized for use in safety critical applications such as life support where a failure of the TI product would reasonably be expected to cause severe personal injury or death unless officers of the parti...

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