Texas Instruments SLUU477 User Manual

User's Guide

SLUU477–December 2010

800mA, Single-Input, Single Cell Li-Ion Battery Solar

Charger with Power Path

This user's guide describes the features and operation of the bq24210EVM Evaluation Module (EVM). The EVM assists users in evaluating the bq24210 solar chager. The EVM is also called the HPA678. The manual includes the bq24210EVM bill of materials, board layout, and schematic.

Contents

1 Introduction .................................................................................................................. 2

1.1 EVM Features ...................................................................................................... 2

1.2 General Description ................................................................................................ 2

1.3 I/O Description ...................................................................................................... 2

1.4 Control and Key Parameters Setting ............................................................................ 3

1.5 Recommendd Operating Conditions ............................................................................ 3

2 Test Summary ............................................................................................................... 4

2.1 Definitions ........................................................................................................... 4

2.2 Safety ................................................................................................................ 4

2.3 Quality ............................................................................................................... 4

2.4 Apparel .............................................................................................................. 4

2.5 Equipment ........................................................................................................... 5

2.6 Equipment Setup ................................................................................................... 5

2.7 Procedure ........................................................................................................... 6

3 PCB Layout Guideline ...................................................................................................... 6

4 Bill of Materials, Board Layout and Schematics ........................................................................ 7

4.1 Bill of Materials ..................................................................................................... 7

4.2 Board Layout ....................................................................................................... 8

4.3 Schematics ........................................................................................................ 11

List of Figures

1 Original Test Setup for HPA678 (bq24210 EVM)....................................................................... 5

2 Top Assembly ............................................................................................................... 8

3 Top Layer .................................................................................................................... 9

4 Bottom Layer............................................................................................................... 10

5 bq24210 EVM Schematic ................................................................................................ 11

List of Tables

1 I/O Description............................................................................................................... 2

2 Control and Key Parameters Setting..................................................................................... 3

3 Recommendd Operating Conditions ..................................................................................... 3

4 Bill of Materials.............................................................................................................. 7

SLUU477–December 2010 800mA, Single-Input, Single Cell Li-Ion Battery Solar Charger with Power Path

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Introduction

1 Introduction

1.1 EVM Features

• Evaluation Module for bq24210

• 800mA, Single-Input, Single Cell Li-Ion Battery Solar Charger with Power Path

• Resistor-programmable setting for charge current and input voltage dynamic power management

• LED Indication for Status

• Test Points for Key Signals Available for Testing Purpose – Easy Probe Hook-up

• Jumpers Available – Easy to Change Setting

1.2 General Description

The bq24210 series of devices are highly integrated Li-ion linear chargers devices targeted at space-limited portable applications. The high input voltage range with input overvoltage protection supports low-cost unregulated adapters. The input voltage regulation loop with programmable input voltage regulation threshold make it suitable for charging from alternative power sources, such as solar panel or inductive charging pad. The IC has a single power output that charges the battery. A system load can be placed in parallel with the battery as long as the average system load does not keep the battery from charging fully during the 10 hour safety timer.

The battery is charged in three phases: conditioning, constant current and constant voltage. In all charge phases, an internal control loop monitors the IC junction temperature and reduces the charge current if an internal temperature threshold is exceeded.

For details, see BQ24210 data sheet (SLUSA76).

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1.3 I/O Description

Jack Description

J1–VBUS Positive input J1–GND Negative input J2–BAT Charger output J2–GND Ground J2–TS Temperature qualification input J3-GND Ground J3-VDPM Programs the input voltage regulation threshold J3-CHG Charge status indication J3-EN Chip enable control J3-PG Power present indication J4-ISET Programs the fast-charge current setting J4-VTSB TS bias reference voltage pin, regulated output J4-GND Ground

Table 1. I/O Description

800mA, Single-Input, Single Cell Li-Ion Battery Solar Charger with Power Path SLUU477–December 2010

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( )

DPM DPM_ 1

VDPM

DPM

VBUS_ VBUS _

R =

KVBUS_

ISET

O UT

R =

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1.4 Control and Key Parameters Setting

Table 2. Control and Key Parameters Setting

Jack Description Factory Setting

JP1 Programs the fast-charge current setting. 500mA when JP1 ON; external setting Jumper OFF (external setting)

JP2 Connect /EN and /PG together when JP2 ON to enable charger when power present Jumper OFF (external /EN) JP3 Programs the input voltage regulation threshold. 4.5V when JP3 ON; external setting Jumper OFF (external setting)

JP4 Limited power charge mode (LPCM) when JP4 ON; normal operation when JP4 OFF Jumper OFF (normal operation) JP5 Select external TS input or internal TS setting Jumper ON 1-2 (external TS)

JP6 The pull-up power source supplies for the LEDs Jumper ON 2-3 (VBUS)

JP7 Charger ON/OFF command Jumper ON 1-2 (charger OFF)

when JP1 OFF

when JP3 OFF.

1-2 : External TS input 2-3 : Internal TS setting

1-2 : BAT 2-3 : VBUS

1-2 : OFF 2-3 : ON

1.5 Recommendd Operating Conditions

Table 3. Recommendd Operating Conditions

Description Min Typ Max Unit Notes

Supply voltage, V Battery voltage, V Supply current Maximum input current 0 0.8 A Charge current, I Operating junction temperature 0 125 °C

range, T

BUS

BAT

chrg

Input voltage 4.5 7.3 V Voltage applied at VBAT terminal of J2 0 4.2 V

Battery charge current 0 0.8 A

Introduction

An external resistor is used to program the VBUS_DPM. The programming resistor, R

is dictated by

VDPM

the following equation:

Where:

VBUS_ VBUS_ K

VBUS_DPM

If VDPM pin is shorted to VSS, the VBUS_

is the desired input voltage regulation voltage threshold;

DPM

is the built-in offset threshold, nominally 3.5V

DPM_1

is a gain factor found in the electrical specification.

should be clamped to 3.65V.

DPM

If the VDPM pin is floated (open circuit), the IC operates in Battery Tracking Mode. In this case, VBUS DPM threshold is internally set as V

, which is BAT+100mV (BAT>3.65V) or 3.75V (BAT≤3.4V).

TRK

Connecting JP3 set 4.5V VDPM on EVM.

An external resistor is used to program the output current (50-800mA). The equation for charge current is:

Where, I

is the desired fast charge current; K

OUT

is a gain factor found in the spec.

ISET

The termination and pre-charge current are internally set at 10% and 20% of fast charge current respectively. The pre-charge-to-fast-charge, V

threshold is set to 2.5V.

lowv

Connecting JP1 set 500mADC for fast charge current and 100mADC for pre-charge current on EVM.

(1)

(2)

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Test Summary

2 Test Summary

2.1 Definitions

This procedure details how to configure the HPA678 evaluation board. On the test procedure, the following naming conventions are followed.

VXXX : External voltage supply name (VBUS, VBAT) LOADW: External load name (LOADR, LOADI) V(TPyyy): Voltage at internal test point (TPyyy). For example, V(TP1) means the voltage at TP1. V(Jxx): Voltage at jack terminal (Jxx). V(XXX): Voltage at (XXX). For example, V(VDPM) means the voltage at the test point which is

V(XXX, YYY): Voltage across point XXX and YYY. I(JXX(YYY)): Current going out from the YYY terminal of jack XX. Jxx(BBB): Terminal or pin BBB of jack xx Jxx ON : Internal jumper Jxx terminals are shorted Jxx OFF: Internal jumper Jxx terminals are open Jxx (-YY-) ON: Internal jumper Jxx adjacent terminals marked as "YY" are shorted Measure:→A,B Check specified parameters A, B. If measured values are not within specified limits the

Observe →A,B Observe if A, B occur. If they do not occur, the unit under test has failed.

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marked "VDPM".

unit under test has failed.

Assembly drawings have location for jumpers, test points and individual components

2.2 Safety

1. Safety Glasses are to be worn.

2. This test must be performed by qualified personnel trained in electronics theory and understand the

risks and hazards of the assembly to be tested.

3. ESD precautions must be followed while handling electronic assemblies while performing this test.

4. Precautions should be observed to avoid touching areas of the assembly that may get hot or present a

shock hazard during testing.

2.3 Quality

1. Test data shall be made available upon request by Texas Instruments.

2.4 Apparel

1. Electrostatic smock

2. Electrostatic Gloves or finger cots

3. Safety Glasses

4. Ground ESD wrist strap

800mA, Single-Input, Single Cell Li-Ion Battery Solar Charger with Power Path SLUU477–December 2010

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