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
Considerations With Evaluating the TPS62730
.........................................................................
3
Performance Specification Summary
.....................................................................................
4
Test Summary
...............................................................................................................
4.1
Equipment
...........................................................................................................
4.2
Equipment and EVM Setup
.......................................................................................
4.3
Test Procedure Using a Single Cell Li-Ion Battery
............................................................
5
Schematic, Physical Layouts and Bill of Materials
.....................................................................
5.1
Schematic
...........................................................................................................
5.2
Physical Layouts
...................................................................................................
5.3
Bill of Materials
.....................................................................................................
6
Oscilloscope Traces
........................................................................................................
List of Figures
1
EVM Schematic and Evaluation Setup
...................................................................................
2
TPS62730 EVM Board Schematic
........................................................................................
3
Assembly Layer
.............................................................................................................
4
Top Layer
....................................................................................................................
5
Bottom Layer
................................................................................................................
6
CH1: Phase; CH2: Output Ripple, Vin = 3.3 V, and 21-
Ω
Load
......................................................
7
PFM Mode at Low Load, 40 mA
–
CH1: Phase; CH2: Output Ripple; 0.2
µ
s/div
..................................
8
PFM Mode at Low Load, 11 mA
–
CH1: Phase; CH2: Output Ripple; 1
µ
s/div
....................................
9
Transition From Switching Converter to Bypass Mode by Removing Input Power
–
CH1: Phase Node;
CH2: STAT Pin
..............................................................................................................
10
Transition From Converter Switch Mode to Bypass Mode by Pulling ON/BYP Pin Low
..........................
11
Transition From Bypass Mode to Converter Switch Mode by Pulling ON/BYP Pin High
........................
12
Startup by Hot-Plugging the Input Power Source
.....................................................................
13
Transient Output Load Step From 50 mA to 100 mA
.................................................................
14
Transient Output Load Step From 100 mA to 50 mA
.................................................................
1
SLVU455
–
April 2011
TPS62730 Stepdown Converter With Bypass Mode for Ultralow-Power Wireless
Applications
Copyright
©
2011, Texas Instruments Incorporated