Texas Instruments bq24261M User manual

User's Guide
SLUUBB5A–April 2015–Revised October 2015
User's Guide for WCSP-Packaged bq24261M 3-A Battery
Charger Evaluation Module
The bq24261M evaluation module is a complete charger module for evaluating compact, flexible, high-
efficiency, USB-friendly, switch-mode charge management solutions for single-cell, Li-ion and Li-polymer
batteries used in a wide range of portable applications.
Contents
1 Introduction ................................................................................................................... 2
1.1 bq24261M IC Features............................................................................................. 2
1.2 bq24261M EVM Features ......................................................................................... 2
1.3 Schematic............................................................................................................ 3
1.4 I/O Description ...................................................................................................... 4
1.5 Test Points........................................................................................................... 4
1.6 Control and Key Parameters Setting............................................................................. 5
1.7 Recommended Operating Conditions............................................................................ 5
2 Test Summary................................................................................................................ 6
2.1 Definitions............................................................................................................ 6
2.2 Recommended Test Equipment .................................................................................. 6
2.3 Recommended Test Equipment Setup .......................................................................... 8
2.4 Recommended Test Procedure ................................................................................. 10
3 Printed-Circuit Board Layout Guideline.................................................................................. 12
4 Bill of Materials and Board Layout ...................................................................................... 13
4.1 Bill of Materials .................................................................................................... 13
4.2 Board Layout....................................................................................................... 14
List of Figures
1 bq24261MEVM Schematic ................................................................................................. 3
2 BAT_Load (PR1010) Schematic........................................................................................... 7
3 Connections of HPA172 Kit ................................................................................................ 8
4 Original Test Setup for bq24261MEVM-691 ............................................................................. 9
5 Main Window of bq24261MSW Evaluation Software.................................................................. 10
6 Top Assembly Layer....................................................................................................... 14
7 Top Layer ................................................................................................................... 15
8 First Internal Layer ......................................................................................................... 16
9 Second Internal Layer ..................................................................................................... 17
10 Bottom Layer................................................................................................................ 18
11 Bottom Assembly Drawing................................................................................................ 19
List of Tables
1 Bill of Materials - bq24261MEVM-691 .................................................................................. 13
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Introduction www.ti.com
1 Introduction
1.1 bq24261M IC Features
The bq24261M device integrates a synchronous PWM controller, power MOSFETs, input-current sensing,
high-accuracy current and voltage regulation, charge termination and power path management into a
small WCSP package. The charge parameters can be programmed through an I2C interface. Key IC
features include:
• High-efficiency, fully-integrated, NMOS-NMOS, synchronous buck charger with 1.5-MHz frequency
• Charge time optimizer
• Integrated power FETs for up to 3-A charge rate
• 5-V, 1-A OTG VBUS supply
• Power path management between battery and system voltages
For details, see the bq24261M data sheet (SLUSC09).
1.2 bq24261M EVM Features
The bq24261M evaluation module (EVM) on PCB PWR691 provide a complete charger module for
evaluating compact, flexible, high-efficiency, USB-friendly, switch-mode battery charge and power path
management solution for single-cell, Li-ion and Li-polymer battery-powered systems used in a wide range
of portable applications. Key EVM features include:
• Terminal blocks and standard headers for IN, SYS, BAT, TS
• Programmable battery voltage, charge current, input current, and status via I2C interface
• IN operating up to 10.5 V for bq24261M
• LED indication for status signals
• Test points for key signals available for testing purposes. Easy probe hook-up
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J13
BAT
up to 4.44V, 3A
BAT
10µF
C6
DNP
GND
BAT
PGND A1
PGND A2
PGND A3
PGND A4
PGND A5
PGND A6
PMID
B1
SW B2
SW B3
SW B4
SW B5
SW B6
IN
C1
IN
C2
IN
C3
IN
C4
CD
C5 BOOT C6
SDA
D1
SCL
D2
NC
D3
TS D5
DRV D6
STAT
E1
INT
E2
SYS E3
SYS E4
SYS E5
SYS E6
AGND F1
BGATE
F2
BAT F3
BAT F4
BAT F5
BAT F6 PSEL
D4
U1
bq24261M
1µF
C4
GND
GND
GND
GND
1µF
C7
GND
22µF
C5
up to 6V, 3A
GND
INT
IN
STAT
DRV
TS
IN
PSEL
GND
GND
GND
DM
SCL
GND
SDA
GND
GND
DRV
SW
L1
SPM4012T-1R5M
DRV
1
2
3
JP5
HIGH
CD
DRV
LOW
DRV
DRV
GND
GND
GND
EXT
5.62k
R5
TP9
TS
GND
TS
DRV
GND
EXT
Red
D2
Green
D1
TS
SCL
SIM
4
1
2
3
J15
22-05-3041
12.4k
R6
STAT
GND
INT
TP1TP2 TP4 TP5 TP7
GND
SW
GND
200
R2
BAT
SDA
GND
SYS
100k
R7
GND
1.50k
R3
1.50k
R4
TP6 TP8
IN
INTSTAT
200
R1
SYS
IN
GND
J14
ED555/2DS
J7
ED555/2DS
J1
ED555/2DS
J9
ED555/2DS
1µF
C2
1µF
C1
10µF
C8DNP
J5
J6
J3
JP3JP2
J8
J4
1
2
3
JP6
TP3
SYS
SYS
GND
GND
J11
ED555/2DS
J10
GND
TP10
TP11
1
2
3
JP4
Q1
CSD25402Q3A
1.00M
R8
BGATE
BGATE
SYS (OFF)
BGATE
GATE
0.033µF
C3
www.ti.com Introduction
1.3 Schematic
Figure 1 illustrates the bq24261M schematic.
Figure 1. bq24261MEVM Schematic
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1.4 I/O Description
Header/Terminal Block Description
J1– IN/GND Input power positive and negative terminal
J2 – Do not use Do not use
J3 - GND DRV linear regulator negative header
J4 - IN Input power positive header
J5 - GND Battery negative header
J6 - DRV DRV linear regulator positive output
J7 - DRV/GND DRV linear regulator positive and negative terminals
J8 - GND Input power negative header
J9 - EXT TS/GND External thermistor terminal
J10 - GND SYS output negative header
J11 - SYS/GND SYS output positive and negative terminal
J12 - SYS SYS output positive header
J13 - BAT Battery positive header
J14 - BAT/GND Battery positive and negative header
J15 - USB-to-GPIO USB-to-GPIO box keyed connector
1.5 Test Points
Test Point Description
TP1 BAT
TP2 SW
TP3 GND
TP4 SYS
TP5 IN
TP6 STAT
TP7 GND
TP8 INT
TP9 TS
TP10 SCL
TP11 SDA
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www.ti.com Introduction
1.6 Control and Key Parameters Setting
Jumper Description Default Factory Setting
JP1 Leave jumper open OPEN
JP2 Shorting jumper to connect DRV to anode of D1 STAT LED SHORTED
JP3 Shorting jumper to connect DRV to anode of D1 INT LED SHORTED
GATE = SYS: External PFET's gate tied to SYS and therefore disabled.
JP4 GATE = BGATE: External PFET's gate tied to BGATE pin and therefore controlled by GATE=BGATE
IC.
CD = LO: Charge disable low for normal operation
JP5 CD = LO
CD = HI: Charge disable high to disable the buck converter and enter Hi-Z mode
TS = SIM: Connects a potentiometer to the TS pin so that the potentiometer can
simulator a thermistor. The potentiometer has been preset per R5 and R6 so that the
TS voltage is 0.5 x V (DRV).
JP6 TS=SIM
TS = EXT: Connects the TS pin to an external thermistor through J9. The resistor
divider formed by R5 and R6 has been sized to accommodate a 10-kΩthermistor. If a
different thermistor is used, R5 and R6 must be resized.
PSEL = LO: Input current limit is set to 1.5 A until changed by I2C.
JP7 PSEL = HI
PSEL = HI: Input current limit is set to USB100 until changed by I2C.
1.7 Recommended Operating Conditions
Min Typ Max Unit
Supply voltage, VIN Input voltage from ac adapter 4.2 10.0 V
System voltage, VSYS Voltage output at SYS terminal ; depends on VBAT voltage 3.4 VBATR V
and status of VINDPM) EG+3%
Battery voltage, VBAT Voltage output at VBAT terminal (registers set via I2C 1.9 4.2 4.44 V
communication)
Supply current, IIN(MAX) Maximum input current from ac adapter input (registers set 0.1 2.5 A
via I2C communication)
Fast charge current, Battery charge current (registers set via I2C communication) 0.500 3.0 A
ICHRG(MAX)
Operating junction temperature range, TJ-40 125 °C
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Test Summary www.ti.com
2 Test Summary
This procedure describes one test configuration of the bq24261MEVM-691 evaluation board for bench
evaluation.
2.1 Definitions
The following naming conventions are followed.
VXXX : External voltage supply name (VADP, VBT, VSBT)
LOADW: External load name (LOAD1, LOAD2)
V(TPyyy): Voltage at internal test point TPyyy. For example, V(TP12) means the voltage at
TP12.
V(Jxx): Voltage at header Jxx
V(TP(XXX)): Voltage at test point XXX. For example, V(ACDET) means the voltage at the test
point which is marked as ACDET.
V(XXX, YYY): Voltage across point XXX and YYY.
I(JXX(YYY)): Current going out from the YYY terminal of header XX.
Jxx(BBB): Terminal or pin BBB of header xx.
JPx ON : Internal jumper Jxx terminals are shorted.
JPx OFF: Internal jumper Jxx terminals are open.
JPx (-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 unit under test has failed.
Observe →A,B Observe if A, B occur. If they do not occur, the unit under test has failed.
Assembly drawings have location for jumpers, test points, and individual components.
2.2 Recommended Test Equipment
2.2.1 Power Supplies
1. Power Supply #1 (PS #1) capable of supplying 6 V at 2 A is required.
2. If not using a battery as the load, then power supply #2 (PS #2) capable of supplying up to 5 V at 5 A
is required to power the circuit shown in Figure 2.
2.2.2 Load #1 Between BAT and GND
Testing with an actual battery is the best way to verify operation in the system. If a battery is not available,
then a circuit similar to the one shown in Figure 2 can simulate a battery when connected to a power
supply.
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Figure 2. BAT_Load (PR1010) Schematic
2.2.3 Load #2 Between SYS and GND
Although not required, a resistive load capable of sinking up to 3 A can be used.
2.2.4 Meters
Four equivalent voltage meters (VM #) and two equivalent current meters (CM #) are required. The current
meters must be able to measure 2-A current.
2.2.5 Computer
A computer with at least one USB port and a USB cable is required. The bq24261M evaluation software
must be properly installed.
2.2.6 HPA172 Communication Kit (USB TO GPIO)
An HPA172 USB-to-I2C communication kit is required.
2.2.7 Software
Download Battery Management Studio.zip from the charger's product folder, unzip the file, and double-
click on the SETUP.EXE file. Follow the installation steps.
Because the bq24261M has the watchdog timers enabled, it is recommended that you set the software's
Reset Watchdog Timer to reset every 5 seconds. Otherwise, after 30 seconds of operation, the IC enters
Default mode. Note that the 27-minute safety timer is not reset by this function and eventually times out if
charging does not complete, unless the Safety Timer Time Limit is expanded or disabled via the GUI.
One way to reset the safety timer is to allow the 30-second watchdog timer to expire. See Figure 3 in the
data sheet for more information about the timers.
Also, it is generally helpful to activate the Write On Change functions, in the upper left of the GUI window,
to ON. The Write On Change function writes any changes to the GUI's check boxes, drop-down boxes,
and registers to the IC. Otherwise, the user must click the WRITE button to write changes to the software.
It is recommended that the user periodically click the READ button to find the IC's instantaneous status.
Alternatively, the AutoRead function can be activated to periodically update the GUI with the IC's status.
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2.3 Recommended Test Equipment Setup
1. For all power connections, use short, twisted-pair wires of appropriate gauge wire for the amount of the
current.
2. Set power supply #1 (PS #1) for 6-V, 2-A current limit and then turn off supply.
3. If BAT_Load as shown in Figure 1 is used, connect Power Supply #2 (PS #2) set to approximately 3.6
V to the input side (PS #2+/-) of BAT_Load, then turn off PS #2.
4. Connect the output side of the battery or BAT_Load in series with current meter (multimeter) #2 (CM
#2) to J2 and J6 or J3 (BAT, GND). Ensure that a voltage meter is connected across J2 or TP3 and J6
or TP9 (BAT, GND).
5. Connect VM #3 across J10 or TP7 and J14 or TP9 (SYS, GND).
6. Connect VM #4 across J15 or TP5 and J14 or TP9 (DRV, GND).
7. Connect J17 to EV2400 kit by the 4-pin ribbon cable. Connect the USB port of the EV2400 kit to the
USB port of the computer. The connections are shown in Figure 3.
Figure 3. Connections of HPA172 Kit
8. Ensure jumpers are at the default factory settings per Section 1.6.
9. After the preceding steps have been performed, the test setup for bq24261MEVM-691 is configured as
is shown in Figure 4.
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Figure 4. Original Test Setup for bq24261MEVM-691
10. Turn on the computer. Open the bq24261M evaluation software. The main window of the software is
shown in Figure 5.
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Figure 5. Main Window of bq24261MSW Evaluation Software
2.4 Recommended Test Procedure
The following test procedure may be useful for evaluating the charger IC outside of a real system, if no
battery is available to connect to the output and a simulated battery if needed.
2.4.1 Charge Voltage and Current Regulation of IN in HOST mode
1. Ensure that the Section 2.3 steps are followed.
2. Ensure that the shunts are installed as highlighted in yellow in Figure 4.
3. Connect the output of Power Supply #1 (PS #1), with at least a 4-A current limit setting, in series with
current meter (multimeter) #1 (CM #1) to J1 as shown in Figure 4.
4. Connect voltage meter 1 (VM #1) across J4 and J3 or TP5 and or TP7 (IN, GND).
5. Connect either a real single cell lithium ion battery or battery simulator across J14 or J13/J5 (BAT,
GND) with current meter #2 in series as shown in Figure 4. If using a battery simulator like the one
shown in Figure 2and referred to as BAT_LOAD in Figure 4, configure power supply #2 (PS#2) with at
least 4-A current limit for 3.4 V.
6. Install voltage meter #1 (VM #1) across J4 and J3 or TP5 and TP7 (IN and GND).
7. Install voltage meter #2 (VM #2) across J13 and J5 or TP1 and TP7 (BAT and GND).
8. Install voltage meter #3 (VM #3) across J12 and J10 or TP4 and TP7 (SYS and GND).
9. Voltage meter #4 is optional.
10. Turn on PS #1 and PS #2 if used.
11. Software setup:
• Press the READ button to obtain the current settings.
• Set Write On Change to ON if not already set.
• Set Reset Watchdog Timer to reset every 5 seconds.
• Uncheck Disable Charging if checked.
• Check Enable STAT/INT Outputs.
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