Texas Instruments bq25505, User Manual

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User's Guide
SLUUAA8 – September 2013
User's Guide for bq25505 Battery Charger Evaluation
Module for Energy Harvesting
This user’s guide describes the bq25505 evaluation module (EVM), how to perform a stand-alone
evaluation and how to allow the EVM to interface with the system and host. The boost charger output is
configured to deliver up to 4.2-V maximum voltage to its output, VSTOR, using external resistors. This
voltage is applied to the storage element as long as the storage element voltage at VBAT_SEC is above
the internally programmed undervoltage of 2 V. The VBAT_OK indicator toggles high when VSTOR ramps
up to 3 V and toggles low when VSTOR ramps down to 2.8 V.
Contents
1 Introduction
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2
1.1 EVM Features
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2
1.2 General Description
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2
1.3 Design and Evaluation Considerations
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3
1.4 bq25505EVM Schematic
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4
1.5 EVM I/O Connections
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5
2 EVM Performance Specification Summary
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7
3 Test and Measurement Summary
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7
3.1 Test Setups and Results
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8
4 Bill of Materials and Board Layout
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14
4.1 Bill of Materials
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14
4.2 EVM Board Layout
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15
5 PCB Layout Guideline
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19
List of Figures
1 bq25505EVM Schematic
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4
2 Test Setup for Measuring Boost Charger Efficiency
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8
3 Charger Efficiency versus Input Voltage
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4 Charger Efficiency versus Input Current
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5 Test Setup for Measuring Charger Operation
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6 Charger Operational Waveforms During Battery Charging
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7 Test Setup
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8 Switching from Primary to Secondary Battery
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9 Test Setup for Charging a Super Capacitor on VBAT_SEC
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10 Charging a Super Cap on VBAT_SEC
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11 EVM PCB Top Silk
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15
12 EVM PCB Top Assembly
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13 EVM PCB Top Layer
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14 EVM PCB Bottom Layer
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List of Tables
1 I/O Connections and Configuration for Evaluation of bq25505 EVM
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5
2 Bill of Materials
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14
1 SLUUAA8 – September 2013 User's Guide for bq25505 Battery Charger Evaluation Module for Energy
Harvesting
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