Texas Instruments bq25910EVM-854 User Manual

User's Guide

SLVUB31A–September 2017–Revised March 2018

bq25910EVM-854 Evaluation Module

This user's guide describes the characteristics, operation, and use of the bq25910 Evaluation Module (EVM). A complete schematic diagram, printed-circuit board layouts, and bill of materials (BOM) are included in this document.

Contents

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

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

1.2 I/O Descriptions ..................................................................................................... 2

1.3 Recommended Operating Conditions............................................................................ 4

2 Test Setup and Results ..................................................................................................... 4

2.1 Equipment ........................................................................................................... 4

2.2 Test Setup ........................................................................................................... 5

3 Board Layout ................................................................................................................. 9

4 Schematic and Bill of Materials........................................................................................... 12

4.1 Schematic .......................................................................................................... 12

4.2 Bill of Materials .................................................................................................... 13

List of Figures

1 bq25910EVM-854 Image ................................................................................................... 2

2 bq25910EVM Setup ......................................................................................................... 5

3 bqStudio Device Tabs....................................................................................................... 5

4 bq25910 Registers .......................................................................................................... 6

5 bq25910 WD_RST bit....................................................................................................... 6

6 bq25910 Watchdog Timer Disable ........................................................................................ 7

7 bq25898D Enable HIZ Mode............................................................................................... 7

8 bq25910EVM-854 Top Overlay............................................................................................ 9

9 bq25910EVM-854 Top Solder ............................................................................................. 9

10 bq25910EVM-854 Top Layer .............................................................................................. 9

11 bq25910EVM-854 Signal Layer 1 ......................................................................................... 9

12 bq25910EVM-854 Signal Layer 2 ......................................................................................... 9

13 bq25910EVM-854 Bottom Layer........................................................................................... 9

14 bq25910EVM-854 Bottom Solder ........................................................................................ 10

15 bq25910EVM-854 Bottom Overlay ...................................................................................... 10

16 bq25910EVM-854 Drill Drawing.......................................................................................... 10

17 bq25910EVM-854 Board Dimensions ................................................................................... 10

18 bq25910EVM-854 Schematic............................................................................................. 12

List of Tables

1 Device Data Sheets ......................................................................................................... 2

2 bq25910EVM Ports.......................................................................................................... 3

3 bq25910EVM Jumpers...................................................................................................... 3

4 bq25910EVM Test Points .................................................................................................. 3

5 bq25910EVM Recommended Operating Conditions.................................................................... 4

SLVUB31A–September 2017–Revised March 2018

Submit Documentation Feedback

bq25910EVM-854 Evaluation Module

DC Load

Introduction

6 Bill of Materials ............................................................................................................. 13

1 Introduction

The bq25910 is an integrated three-level switch-mode parallel battery charge management device for single cell Li-ion and Li-polymer batteries. Utilization of the three-level converter reduces solution footprint and volume while maintaining highest switch-mode operation efficiency.

This evaluation module includes both the master and parallel chargers: the bq25898D and the bq25910, respectively. The bq25898D is a highly-integrated 4-A switch-mode battery charge management and system power-path device for single cell Li-ion and Li-polymer battery.

1.1 EVM Features

The device data sheets, listed in Table 1, provide detailed features and operation.

1.2 I/O Descriptions

The bq25910EVM available ports and jumpers are described in Table 2 and Table 3.

www.ti.com

Table 1. Device Data Sheets

Device Data Sheet

bq25910 SLVSDU0

bq25898D SLUSCA6

NOTE: Do not use sense lines and testpoints on the bq25910EVM to carry large amounts of current.

bq25910EVM-854 Evaluation Module

Figure 1. bq25910EVM-854 Image

SLVUB31A–September 2017–Revised March 2018

Submit Documentation Feedback

www.ti.com

Introduction

Table 2. bq25910EVM Ports

Port Description

J1 bq25898D PMID port J2 bq25898D SYS output J3 bq25898D and bq25910 VBUS input J4 Battery connector for both bq25898D and bq25910 J5 I2C Molex connector J6 bq25910 PMID port

Table 3. bq25910EVM Jumpers

Jumper Description

JP1 Pullup selection jumper. Choose between SYS or BAT. Installed to SYS JP2 bq25898D battery sense line Installed JP3 bq25910 INT pin jumper Installed JP4 bq25898D CE pin (charge enabled) Installed JP5 bq25898D REGN to TS network connection Installed JP6 TS network connection to potentiometer Installed

JP7 JP8 bq25898D OTG to GND pin connection Installed

JP9 bq25898D ILIM to GND pin connection Not Installed JP10 bq25910 IND_SNS pin connection Installed JP11 bq25910 BATP sense line connection Installed JP12 bq25910 BATN sense line connection Installed

TS to GND connection. Can also be used to attach an external 103AT thermistor.

Default

Configuration

Not Installed

Table 4. bq25910EVM Test Points

Test Point Description

VBUS1_s Sense line for the bq25898D VBUS for efficiency measurement

PMID1 Connection to the bq25898D PMID plane

VBUS2_s Sense line for the bq25910 VBUS for efficiency measurement

PMID2 Connection to the bq25910 PMID plane BAT_s bq25898D battery sense line

BATP bq25910 positive battery sense line BATN bq25910 negative battery sense line

GND_s bq25910 sense line to GND plane near IC for efficiency measurement

SW1 bq25898D switch node SW2 bq25910 switch node

VOUT_910_s bq25910 converter output for efficiency measurement

CFLY+/CFLY– Differential test points for the bq25910 CFLY capacitor

CDRV+/CDRV– Differential test points for the bq25910 CDRV capacitor

INT2 bq25910 Interrupt pin CAUX bq25910 CAUX capacitor REGN bq25910 REGN output

SLVUB31A–September 2017–Revised March 2018

Submit Documentation Feedback

bq25910EVM-854 Evaluation Module

Introduction

1.3 Recommended Operating Conditions

Table 5. bq25910EVM Recommended Operating Conditions

Symbol Description MIN TYP MAX Unit

VBUS Input voltage from AC adapter 3.9 14 V

IBUS Input supply current from AC adapter 3.6 A

VBAT Battery voltage applied at J4 0 4.775 V

IBAT bq25910 output current 0 6 A

2 Test Setup and Results

2.1 Equipment

In order to evaluate the bq25910EVM, the following are required:

• Power Supply: Capable of providing up to 14 V and 3.6 A to be used for VBUS.

• Battery Emulator: A 4-quadrant supply capable of constant voltage ≤ 4.775 V and constant current ≤ 6 A.

• DC Electronic Load: Used to emulate system load.

• Multimeters: Used for voltage measuring and at least 2 current meters capable of measuring 6 A or can use the sense resistors on the board.

• Computer: A computer with at least one USB port and USB cable.

• EV2400 USB-based PC Interface Board: Used to interface with the bq25910EVM via I2C. The EV2400 is purchased separately and is found here.

• bqStudio: Software platform used to send commands to the bq25910EVM via I2C using the EV2400. Download the latest version of bqStudio from ti.com. Double click the bqStudio setup installation file and follow the installation prompts. The software supports Microsoft®Windows®XP and Windows 7 operating systems.

www.ti.com

bq25910EVM-854 Evaluation Module

SLVUB31A–September 2017–Revised March 2018

Submit Documentation Feedback

EV2400

USB

Port

I2C

bq25910EVM

I2C

GND

BAT

VBUS

GND

SYS

GND

Power Supply

Li-ion battery/

battery emulator

DC Load

www.ti.com

2.2 Test Setup

Both the master and parallel chargers are present on the EVM. This user's guide focuses on setting up and evaluation of the bq25910 charger.

Figure 2 shows the connections between the power supplies, EV2400 and the bq25910EVM.

Test Setup and Results

2.2.1 Setting up the bq25898D

This user's guide covers the necessary steps to set up the master charger for parallel charger evaluation.

• Connect the battery emulator to battery connector, J4. Set battery emulator to 3.8 V.

• Using a 4-wire Molex cable (included with EV2400), connect the I2C port to the J5 connector on the EVM. Connect the USB cable to any USB port on the PC with bqStudio installed.

• Apply 5 V at VBUS connector, J3. At this point, the bq25898D should be providing 2 A of charge current to the battery.

• Open bqStudio and select the bq25910EVM from the Charger menu.

• The software allows you to modify both the bq25898D and bq25910 I2C registers. Figure 3 shows the device tabs on bqStudio. Selecting one of them opens the register interface for that particular device and allows the values to be modified via I2C.

• The DC electronic load can be connected at J2 to emulate the system load. Note the 4-A maximum output current of the converter and the maximum 6 A of continuous discharge current from the battery of the bq25898D.

• For full details on the test setup of the bq25898D, refer to bq25898, bq25898D, and bq25898C

PWR730 Evaluation Module.

• To evaluate bq25910 only, place the bq25898D in HIZ mode.

Figure 2. bq25910EVM Setup

Figure 3. bqStudio Device Tabs

SLVUB31A–September 2017–Revised March 2018

Submit Documentation Feedback

bq25910EVM-854 Evaluation Module

Test Setup and Results

2.2.2 Setting up the bq25910

This section describes the options available for evaluation of the bq25910 and how to set up the device for basic evaluation.

• Once the master charger is set up, select the bq25910 Field View tab on bqStudio to continue to set up the parallel charger.

www.ti.com

Figure 4. bq25910 Registers

• Figure 4 shows the configurable registers, single-bit I2C commands and status registers available for the bq25910.

• The bq25910 is a host controlled parallel charger and will automatically shut off when the I2C watchdog timer is not reset within the timer period (40 seconds by default). While in default mode, charging is disabled until the host sets the ENABLE CHARGE bit and resets the watchdog timer via the WD_RST bit (RESET WATCHDOG command).

• After POR, the device is in default mode with the watchdog timer expired. While in default mode, the bq25910 remains in HIZ mode and will not charge the battery.

• The WD_RST bit needs to be set first to force the charger out of default mode. This can be done by setting the RESET WATCHDOG checkbox on bqStudio, see Figure 5 for the location of the WD_RST bit in the Single-bit I2C Selection section of bqStudio.

Figure 5. bq25910 WD_RST bit

• Once WD_RST is set, all the device parameters can be programmed. To keep the device in host mode, the host has to reset the watchdog timer by setting the WD_RST bit before the timer expires or disable the watchdog timer. For the purpose of this evaluation, we disable the watchdog timer by writing REG05[5:4] = 00b. This can be done by using the drop-down menu for the Watchdog Timer setting on the Multi-bit I2C Pulldown Menu. See Figure 6 for the location in bqStudio.

bq25910EVM-854 Evaluation Module

SLVUB31A–September 2017–Revised March 2018

Submit Documentation Feedback

www.ti.com

Figure 6. bq25910 Watchdog Timer Disable

2.2.3 Master and Parallel Chargers Interaction

The bq25898D acts as the master charger and is in charge of pre-conditioning and full termination of the battery. The parallel charger, the bq25910, monitors the battery voltage and compares it to the V threshold. Once the battery voltage rises above the V charging, applying the charge current set on the Fast Charge Current Limit register.

Once the bq25910 begins charging, the master charger can be either placed in HIZ mode or continue running in parallel with the bq25910.

BAT_LOWV

Test Setup and Results

BAT_LOWV

threshold, the bq25910 turns on and begins

2.2.3.1 Master Charger In HIZ mode

Placing the master charger in HIZ mode when the parallel charger begins charging is recommended because this allows evaluating the performance of the bq25910 independently from the master charger. This can be done by navigating to the bq25898D tab on bqStudio and setting the Enable HIZ checkbox, refer to Figure 7.

Figure 7. bq25898D Enable HIZ Mode

SLVUB31A–September 2017–Revised March 2018

Submit Documentation Feedback

bq25910EVM-854 Evaluation Module

+ 14 hidden pages

Texas Instruments bq25910EVM-854 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual