Texas Instruments bq24707EVM User manual

User's Guide
SLUU445B–September 2010–Revised May 2011
bq24707EVM for Multicell, Synchronous, Switch-Mode
Charger With SMBus Interface
The bq24707 evaluation module is a complete charger module for evaluating a multicell (1 to 4 cells)
synchronous notebook charger using the bq24707 devices. Included in this document are the bill of
materials, board art, and schematic.
Contents
1 Introduction .................................................................................................................. 2
1.1 EVM Features ...................................................................................................... 2
1.2 General Description ................................................................................................ 2
1.3 I/O Description ...................................................................................................... 2
1.4 Controls and Key Parameters Setting ........................................................................... 3
1.5 Recommended Operating Conditions ........................................................................... 3
2 Test Summary ............................................................................................................... 3
2.1 Definitions ........................................................................................................... 3
2.2 Equipment ........................................................................................................... 4
2.3 Equipment Setup ................................................................................................... 5
2.4 Procedure ........................................................................................................... 6
3 PCB Layout Guideline ...................................................................................................... 9
4 Bill of Materials, Board Layouts, and Schematic ...................................................................... 10
4.1 Bill of Materials .................................................................................................... 10
4.2 Board Layouts ..................................................................................................... 12
4.3 Schematic ......................................................................................................... 18
List of Figures
1 Connections of the EV2300 Kit ........................................................................................... 5
2 Original Test Setup for bq24707EVM .................................................................................... 5
3 Main Window of the bq24707 Evaluation Software .................................................................... 6
4 Test Setup for bq24707EVM .............................................................................................. 7
5 Top Layer................................................................................................................... 12
6 Second Layer .............................................................................................................. 13
7 Third Layer ................................................................................................................. 14
8 Bottom Layer............................................................................................................... 15
9 Top Assembly.............................................................................................................. 16
10 Bottom Assembly.......................................................................................................... 17
11 Schematic .................................................................................................................. 18
List of Tables
1 I/O Description............................................................................................................... 2
2 Controls and Key Parameters Setting.................................................................................... 3
3 Recommended Operating Conditions.................................................................................... 3
4 EV2300 and bq24707 EVM Connections................................................................................ 5
5 Bill of Materials............................................................................................................. 10
Windows is a trademark of Microsoft Corporation.
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Introduction www.ti.com
1 Introduction
1.1 EVM Features
•Evaluation module for bq24707
•High-efficiency NMOS-NMOS synchronous buck charger with 750-kHz frequency
•User-selectable 1- to 4-cell Li-ion battery voltage
•Programmable battery voltage, charge current, and ac adapter current via SMBus interface
•Flexible Chargeoption() register control via SMBus interface
•AC adapter operating range 5 V to 24 V
•Test points for key signals available for testing purpose. Easy probe hook-up.
•Jumpers available. Easy-to-change connections.
1.2 General Description
The bq24707 evaluation module, also known as the HPA558, is a complete charger module for evaluating
a multicell (1 to 4 cells) synchronous notebook charger using the bq24707 devices. It is designed to
deliver up to 4 A of charge current to Li-ion or Li-polymer applications. The charge current is
programmable by an SMBus interface through the EV2300 interface board. The bq24707EVM does not
come with the EV2300 interface board, so it must be ordered separately.
The bq24707 is a high-efficiency, synchronous battery charger, offering low component count for
space-constrained, multichemistry battery-charging applications. The charge voltage, charge current, input
current, and flexible charge option are programmable via SMBus interface.
The bq24707 uses the internal input current register or external ILIM pin to throttle down PWM modulation
to reduce the charge current.
The bq24707 provides an IFAULT output to alarm if any MOSFET fault or input overcurrent occurs. This
alarm output allows users to turn off input power selectors when the fault occurs. Meanwhile, an
independent comparator with internal reference is available to monitor input current, output current, or
output voltage.
For details, see the bq24707 data sheet (SLUSA78).
1.3 I/O Description
Table 1. I/O Description
Jack Description
J1–DCIN AC adapter, positive output
J1–GND AC adapter, negative output
J2–SYS Connected to system
J2–BAT Connected to battery pack
J2–GND Ground
J3–3.3V External voltage supply 3.3 V
J3–IOUT IOUT pin
J3–ACOK ACOK pin
J4–/IFAULT IC /IFAULT pin
J4–SDA SDA pin output, SMBus data line
J4–SCL SCL pin output, SMBus clock line
J4–GND External power supply, negative output
2bq24707EVM for Multicell, Synchronous, Switch-Mode Charger With SMBus SLUU445B–September 2010–Revised May 2011
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www.ti.com Test Summary
1.4 Controls and Key Parameters Setting
Table 2. Controls and Key Parameters Setting
Jack Description Factory Setting
JP1 Battery voltage set ACDET connection: Jumper installed
Jumper installed: battery voltage can set ACDET voltage when DCIN is unavailable.
Jumper uninstalled: only DCIN can set ACDET.
JP2 External DPM (ILIM control) connection: Jumper uninstalled
When jumper installed, external DPM circuit is active.
When jumper uninstalled, only internal DPM circuit is active.
JP3 Battery voltage power VCC connection: Jumper installed
Jumper installed: battery can power up Vcc when DCIN is unavailable.
Jumper uninstalled: VCC is disconnected from battery.
JP4 bq24707 internal independent comparator setting: Jumper installed on ICMP-2
ICMP-2: Internal comparator to monitor Iout.
2-VCMP: Internal comparator to monitor Vout.
1.5 Recommended Operating Conditions
Table 3. Recommended Operating Conditions
Symbol Description Min Typ Max Unit Notes
Supply voltage, VIN Input voltage from ac adapter input 18 19-20 22 V
Battery voltage, VBAT Voltage applied at VBAT terminal 0 3-16.8 20 V
Supply current, IAC Maximum input current from ac adapter input 0 4.5 A
Charge current, Ichrg Battery charge current 1 3 4 A
Operating junction temperature range, TJ0 125 °C
2 Test Summary
2.1 Definitions
This procedure details how to configure the HPA558 evaluation board. On the test procedure, the
following naming conventions are followed. See the HPA558 schematic for details.
VXXX : External voltage supply name (VADP, VBT, VSBT)
LOADW: External load name (LOADR, LOADI)
V(TPyyy): Voltage at internal test point TPyyy. For example, V(TP12) means the voltage at TP12.
V(Jxx): Voltage at jack terminal 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 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
unit under test has failed.
Observe:→A,B Observe if A, B occur. If they do not occur, the unit under test has failed.
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Test Summary www.ti.com
Assembly drawings have location for jumpers, test points and individual components.
2.2 Equipment
2.2.1 Power Supplies
Power Supply #1 (PS#1): a power supply capable of supplying 20 V at 5 A is required.
Power Supply #2 (PS#2): a power supply capable of supplying 5 V at 1 A is required.
Power Supply #3 (PS#3): a power supply capable of supplying 20 V at 1 A is required.
2.2.2 Load #1
A 30-V (or greater), 5-A (or greater) electronic load that can operate at constant current mode
2.2.3 Load #2
A HP 6060B 3-V to 60-V/0-A to 60-A, 300-W system dc electronic load or equivalent.
2.2.4 Meters
Seven Fluke 75 multimeters (equivalent or better)
Or four equivalent voltage meters and three equivalent current meters.
The current meters must be capable of measuring a 5-A or greater current.
2.2.5 Computer
A computer with at least one USB port and a USB cable. The EV2300 USB driver and the bq24707 SMB
evaluation software must be properly installed.
2.2.6 EV2300 SMBUS Communication Kit
An EV2300 SMBUS communication kit
2.2.7 Software
Install the EV2300 driver before installing the bq24707 software: Driver (USB EV2300) Installer
XP2K-Last updated Jan28-04.zip or later: This is the EV2300 USB driver. Save and unzip to c:\temp (or
other local directory). Double-click on the setup.exe file. Follow the installation steps.
This software needs to be installed after the EV2300 USB driver: bq24725 EVM setup.zip (SLUC202).
This is the bq24725 SMB evaluation software. It is also used on the HPA558 evaluation. Save and unzip
to c:\temp (or other local directory). Double-click on the SETUP.EXE file. Follow the installation steps:
1. Note: On first inserting the EV2300 into the USB port of the personal computer (PC), the user needs to
follow the instructions of the Found New Hardware Wizard.
2. Allow Windows™to connect to Windows Update to search for software. Then click Next.
3. Select Install software automatically (Recommended). Then click Next.
4. If a window pops up informing that the TI USB Firmware Updater has not passed Windows Logo
testing, click Continue Anyway.
5. If a target file already exists and is newer, do not overwrite the newer file.
6. Click Finish.
4bq24707EVM for Multicell, Synchronous, Switch-Mode Charger With SMBus SLUU445B–September 2010–Revised May 2011
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2003
EV2300
HPA002
VCC
HDQ
VOUT
GND
VOUT
SDA
SCL
GND
NC
SMBD
SMBC
GND
USB
To Computer
USB port
SDA
SCL
GND
To EVM
HDQ
I2C
SMB
I
V
I
V
DCIN
J1
GND J2
GND
BAT
IOUT
J3
SYS
J4
GND
ACOK
3.3 V
SDA
SCL
APPLICATION CIRCUIT
HPA558
bq24707EVM
TP1
U1
Power
supply #2
USB
V
EV2300
Iin
I
Power
supply #1
/FAULT
ACDRV_EX
www.ti.com Test Summary
2.3 Equipment Setup
1. Set the power supply #1 for 0 V ±100 mVdc with the current limit set to >5 A, and then turn off supply.
2. Connect the output of power supply #1 in series with a current meter (multimeter) to J1 (DCIN, GND).
3. Connect a voltage meter across J1 (DCIN, GND).
4. Set the power supply #2 for 3.3 V ±100 mVdc, 0.2 ±0.1-A current limit, and then turn off supply.
5. Connect the output of the power supply #2 to J3 (3.3 V) and J4 (GND).
6. Connect a voltage meter across J2 (BAT, GND).
7. Connect a voltage meter across J2 (SYS, GND).
8. Connect J4 (SDA, SCL) and J4 (GND) to the EV2300 kit SMB port. Refer to Table 4 for a connection
reference. Connect the USB port of the EV2300 kit to the USB port of the computer. The connections
are shown in Figure 1.
Table 4. EV2300 and bq24707 EVM Connections
Bq24707EVM-558 EV2300
GND (J4) GND (1)
SCL (J4) SMBC (2)
SDA (J4) SMBD (3)
Figure 1. Connections of the EV2300 Kit
9. Install JP1, JP3. Do not install JP2. Install JP4 on ICMP-2
10. After these steps, the test setup for HPA558 appears as is shown in Figure 2.
Figure 2. Original Test Setup for bq24707EVM
11. Turn on the computer. Open the bq24707 evaluation software. The main window of the software is
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Test Summary www.ti.com
shown in Figure 3.
Figure 3. Main Window of the bq24707 Evaluation Software
2.4 Procedure
2.4.1 AC Adapter Detection Threshold
Ensure that the Section 2.3 steps are followed. Turn on PS#2.
Note that Load #1 and Load #2 are not connected during this step.
Turn on PS#1.
Increase the output voltage of PS#1 to 19.5 V.
Measure →V(TP(ACDET)) = 2.6 V ±0.1 V
Measure →V(TP(ACOK)) = 0.1 V ±0.1 V
Measure →V(J2(SYS)) = 19.5 V ±0.5 V
Measure →V(TP(REGN)) = 6 V ±0.5 V
Measure →V(J2(BAT, GND)) = 1 V ±1 V
2.4.2 Charger Parameters Setting
In the software main window, click all the Read buttons. Ensure that no error information is generated.
If a error information window pops up with this message, "USB Error. Insure USB cable is connected and
Driver is working.”Do the following steps:
1. Click OK. Then close main window that shows as Figure 3, and disconnect USB cable.
6bq24707EVM for Multicell, Synchronous, Switch-Mode Charger With SMBus SLUU445B–September 2010–Revised May 2011
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Ibat
V
Isys
V
ILoad
#1
Load
#2
I
DCIN
J1
GND J2
GND
BAT
IOUT
J3
SYS
J4
GND
ACOK
3.3V
SDA
SCL
APPLICATION CIRCUIT
HPA558
bq24707EVM
TP1
U1
Power
supply #2
USB
V
EV2300
Iin
I
Power
supply #1
ACDRV_EX
www.ti.com Test Summary
2. Check 3.3-V power supply (PS#2) and power supply #1 (PS#1) voltage on the EVM board.
3. Disconnect any other unsure SMBus connection. Plug in USB cable back to the original EVM2300
installation USB port.
4. Open the bq24707 evaluation software. The main window of the software is shown in Figure 3.
In the software main window, click all the Read buttons.
Type in “512”(mA) in the Charge Current DAC, and click Write. This sets the battery charge
current regulation threshold.
Type in “12592”(mV) in the Charge Voltage DAC, and click Write. This sets the battery
voltage regulation threshold.
Measure V(J2(BAT)) = 12.6 V ±200 mV
→
2.4.3 Charge Current and AC Current Regulation (DPM)
Type in “7905”in the Charge Option, and click Write; this disables charging.
Connect the Load #2 in series with a current meter (multimeter) to J2 (BAT, GND). Ensure
that a voltage meter is connected across J2 (BAT, GND). Turn on the Load #2. Use the
constant voltage mode. Set the output voltage to 10.5 V.
Connect the output of the Load #1 in series with a current meter (multimeter) to J2 (SYS,
GND). Ensure that a voltage meter is connected across J2 (SYS, GND). Turn on the power
of the Load #1. Set the load current to 30 A ±50 mA but disable the output. The setup is
now like that shown in Figure 4 for HPA558. Ensure that Ibat = 0 A ±10 mA and Isys = 0 A
±10 mA.
Figure 4. Test Setup for bq24707EVM
Type in “7904”in the Charge Option, and click Write; this enables charging.
Measure →Ibat = 500 mA ±100 mA
Type in “2944”(mA) in the Charge Current DAC, and click Write. This sets the battery charge
current regulation threshold to 2.944 A.
Measure →Ibat = 3000 mA ±300 mA
Measure →V(TP(IOUT)):= 340 mV ±40 mV
Enable the output of the Load #1.
Measure →Isys = 3000 mA ±300 mA, Ibat = 1600 mA ±300 mA, Iin = 4100 mA ±400 mA
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Measure →V(TP(IOUT)) = 820 mV ±100 mV
Turn off the Load #1.
Measure →Isys = 0 ±100 mA, Ibat = 3000 mA ±300 mA.
2.4.4 Power Path Selection
Type in “7905”in the Charge Option, and click Write; this disables charging.
Replace Load #2 and current meter with PS#3. Ensure that a voltage meter is connected
across J2 (BAT, GND). Enable the output of the PS #3. Ensure that the output voltage is 10 V
±500 mV.
Measure →V(J2(SYS)) = 19.5 V ±1 V (adapter connected to system)
Turn off PS#1.
Measure →V(J2(SYS)) = 10 V ±1 V (battery connected to system)
Measure →V(J2(BAT)) = 10 V ±1 V (battery connected to system)
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www.ti.com PCB Layout Guideline
3 PCB Layout Guideline
The switching node rise and fall times must be minimized for minimum switching loss. Proper layout of the
components to minimize high-frequency current path loop is important to prevent electrical and magnetic
field radiation and high-frequency resonant problems. A printed-circuit board (PCB) layout priority list for
proper layout follows. Lay out the PCB according to this specific order is essential.
1. Place the input capacitor as close as possible to the switching MOSFET’s supply and ground
connections, and use the shortest copper trace connection. These parts must be placed on the same
PCB layer instead of on different layers, and use vias to make this connection.
2. The integrated circuit (IC) must be placed close to the switching MOSFET’s gate terminals. Keep the
gate drive signal traces short for a clean MOSFET drive. The IC can be placed on the other side of the
PCB of switching MOSFETs.
3. Place inductor input terminal as close as possible to switching MOSFET’s output terminal. Minimize the
copper area of this trace to lower electrical and magnetic field radiation, but make the trace wide
enough to carry the charging current. Do not use multiple layers in parallel for this connection.
Minimize parasitic capacitance from this area to any other trace or plane.
4. The charging current sensing resistor must be placed right next to the inductor output. Route the sense
leads connected across the sensing resistor back to the IC in the same layer, close to each other
(minimize loop area), and do not route the sense leads through a high-current path. Place decoupling
capacitor on these traces next to the IC.
5. Place output capacitor next to the sensing resistor output and ground.
6. Output capacitor ground connections need to be tied to the same copper that connects to the input
capacitor ground before connecting to system ground.
7. Use single ground connection to tie charger power ground to charger analog ground. Just beneath the
IC, use analog ground copper pour, but avoid power pins to reduce inductive and capacitive noise
coupling.
8. Route analog ground separately from power ground. Connect analog ground, and connect power
ground separately. Connect analog ground and power ground together using power pad as the single
ground connection point, or use a 0-Ωresistor to tie analog ground to power ground (power pad must
tie to analog ground in this case, if possible).
9. Decoupling capacitors must be placed next to the IC pins; make trace connection as short as possible.
10. It is critical that the exposed power pad on the backside of the IC package be soldered to the PCB
ground. Ensure that sufficient thermal vias are directly under the IC, connecting to the ground plane on
the other layers.
9
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Bill of Materials, Board Layouts, and Schematic www.ti.com
4 Bill of Materials, Board Layouts, and Schematic
4.1 Bill of Materials
Table 5. Bill of Materials
bq24707 RefDes Value Description Size Part Number MFR
-001
1 C1 2.2 µF Capacitor, Ceramic, 25V, X7R, 10% 1210 Std Std
6 C2, C3, C4, C5, 10 µF Capacitor, Ceramic, 25V, X7R, 10% 1206 Std Std
C6, C7
0 C8, C13, C18, OPEN Capacitor, Ceramic, 25V, X7R, 10% 603 Std Std
C27
4 C9, C10, 1 µF Capacitor, Ceramic, 25V, X5R, 10% 603 Std Std
C20,C28
2 C11, C26 0.01 µF Capacitor, Ceramic, 25V, X7R, 10% 603 Std Std
1 C12 6.8 nF Capacitor, Ceramic, 25V, X7R, 10% 603 Std Std
8 C14, C15, C16, 0.1 µF Capacitor, Ceramic, 25V, X7R, 10% 603 Std Std
C17, C19, C23,
C24, C25
1 C21 0.047 µF Capacitor, Ceramic, 25V, X7R, 10% 603 Std Std
1 C22 100 pF Capacitor, Ceramic, 25V, X7R, 10% 603 Std Std
1 C29
2 D1, D4 BAT54-V-G Diode, Schottky, 200-mA, 30-V SOT23 BAT54-V-G Vishay-Liteon
1 D2 BAT54C-V-G Diode, Dual Schottky, 200-mA, 30-V SOT23 BAT54C-V-G Vishay-Liteon
1 D3 1SS400 Diode, High-Speed Switching 80V, SOD-523 1SS400 Toshiba
100mA
1 D5 PDS1040 Diode, 10A 40V Schottky Barrier PowerDI 5 PDS1040 Diodes
Rectifier
1 D6 BAT30K Small signal Schottky diodes, 300mA, SOD-523 BAT30KFILM STMicroelectronics
30V
1 J1 ED120/2DS Terminal Block, 2-pin, 15-A, 5.1mm 0.40 x 0.35 inch ED120/2DS OST
1 J2 ED120/3DS Terminal Block, 3-pin, 15-A, 5.1mm 0.60 x 0.35 inch ED120/3DS OST
2 J3, J4 ED555/4DS Terminal Block, 4-pin, 6-A, 3.5mm 0.55 x 0.25 inch ED555/4DS OST
3 JP1, JP2, JP3 PEC02SAAN Header, Male 2-pin, 100mil spacing, 0.100 inch x 2 PEC02SAAN Sullins
(2-pin strip)
1 JP4 PEC03SAAN Header, Male 3-pin, 100mil spacing, 0.100 inch x 3 PEC03SAAN Sullins
(3-pin strip)
4 929950-00 Shorting jumpers, 2-pin, 100mil 929950-00 3M/ESD
spacing,
1 L1 4.7 µH Inductor, SMT 0.255 x 0.270 inch IHLP2525CZER4R7M0 Vishay
1
2 Q1, Q3 Si4435DDY-T1 MOSFET, PChan, -30V, -9A, 35millohm PWRPAK S0-8 Si4435DDY-T1 Vishay
0 Q2 FDS6680A MOSFET, NChan, 30V, 12.5A, PWRPAK S0-8 FDS6680A Fairchild
9.5millohm
2 Q4, Q5 Sis412DN-T1 MOSFET, NChan, 30V, 12A, 30millohm PWRPAK 1212 Sis412DN-T1 Vishay
1 Q6 MMST3904-7-F Trans, NPN, 40V, 200mA SOT-323 MMST3904-7-F Diodes
0 Q7 BSS138W-7-F MOSFET, Nch, 50V, 200mA, SOT-323 BSS138W-7-F Diodes
0 Q8 Si1304BDL-T1 MOSFET, Nch, 30V, 0.9A, 270 mΩSOT-323 Si1304BDL-T1 Vishay
1 Q9 Si1304BDL-T1 MOSFET, Nch, 30V, 0.9A, 270 mΩSOT-323 Si1304BDL-T1 Vishay
1 Q10 DCX124EK-7-F Transistor, Dual Complimentary SC-74 DCX124EK-7-F Diodes
Pre-Biased 50V, 100mA
2 R1, R2 0.01 Resistor, Chip, 3/4W, 1% 150PPM, 1206 PMR18EZPFU10L0 or Rohm Vishay/Dale
Resistor, Chip, 1W, 1% 75 PPM WSLP1206R0100FEA
2 R3, R5 0 Resistor, Chip, 1/16W, 5% 603 Std Std
1 R4 7.5 Resistor, Chip, 0.5W, 5% 603 Std Std
2 R6, R7 3.9 Resistor, Chip, 0.5W, 5% 1210 Std Std
0 R8, R9 4.02k Resistor, Chip, 1/10W, 1% 603 Std Std
0 R10 OPEN Resistor, Chip, 1/16W, 1% 603 Std Std
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