User's Guide
SLUU305 – March 2008
bq24085/6/7/8 Evaluation Module
1
Introduction
This user’s guide describes the bq24085/6/7/8 evaluation module (EVM) that provides a convenient
method for evaluating the performance of a charge management solution for portable applications using
the bq24085/6/7/8 product family. The charger is designed to deliver up to 750 mA of continuous charge
current for single-cell Li-Ion or Li-polymer applications using a DC power supply.
1.1
Background
The bq24085/6/7/8 series are highly integrated Li-Ion and Li-polymer linear chargers, targeted at
space-limited portable applications. The bq24085/6/7/8 series offers a variety of safety features and
functional options, while still implementing a complete charging system in a small package. The battery is
charged in three phases: conditioning, constant or thermally regulated current, and constant voltage.
Charge is terminated based on minimum current. An internal programmable charge timer provides a
backup safety feature for charge termination and is dynamically adjusted during the thermal regulation
phase. The bq24085/6/7/8 automatically re-starts the charge if the battery voltage falls below an internal
threshold; sleep mode is set when the external input supply is removed. Multiple versions of this device
family enable easy design of the bq24085/6/7/8 in cradle chargers or in the end equipment, while using
low-cost or high-end AC adapters.
1.2
Performance Specification Summary
Table 1 and the accompanying table note gives the EVM performance specifications and qualifications.
Table 1. Performance Specification Summary
SPECIFICATION
TEST CONDITIONS
Input DC Voltage, VI(DC)
Battery Charge Current, IO(CHG)
Power Dissipation
(V(DC+) – V(BAT+)) × I(CHG)
MIN
TYP
MAX
VREG +0.5
5
12 (1)
UNITS
Volts
1 (1)
Amperes
1.5
Watts
(1)
•
•
•
This maximum recommended IC input voltage is 16.5 V. The IC has an OVP (overvoltage protection) input circuit that
disables the charging circuit if the threshold is exceeded. Most IC selections are set for 6.5 V, but some are set as high as
12 V (see SLUS784 data sheet). The EVM can handle an input voltage up to the recommended maximum of 16.5 V, but
the IC will shut down due to the internal voltage protection.
It is recommended that in normal operation the IC be designed and run below the thermal regulation junction temperature of
125°C. The thermal loop can run continuously without any issues, but the suggested thermal loop operational use is for
more harsh environments where the ambient temperature is high (for example, in an automobile during the summer) or with
an incorrect adaptor with a higher input voltage.
For typical input and ambient conditions with the PowerPAD™ tied to a copper plane, one can expect 1.5 W of heat
dissipation prior to the thermal loop reducing the current. PdissIC = ICHG x (VDC+ - VBAT+). For the worst-case, steady-state
thermal condition, VBAT+ = 3.4 VDC (the battery when transitioning from precharge to fast charge reaches a steady-state
value after approximately 2 minutes). If the thermal regulation limit of 125°C is reached, then the charging current is
adjusted lower.
SLUU305 – March 2008
Submit Documentation Feedback
bq24085/6/7/8 Evaluation Module
1
www.ti.com
Test Summary
2
Test Summary
This section describes:
• Input/Output and Jumper Connections
• Test Procedure Using Single Cell Li-ion Battery
• Alternative Test Procedures (Without Battery)
• Required Equipment
• Test Equipment Setup
• Test Procedure
2.1
Input/Output and Jumper Connections
The bq24085/6/7/8 EVM board requires a 5-VDC, 1-A power source to provide input power and a
single-cell Li-ion or Li-polymer battery pack. The test setup connections and jumper setting selections are
configured for a stand-alone evaluation but can be changed to interface with external hardware such as a
microcontroller.
Table 2. I/O and Jumper Connections
2.2
Jack
Connect To:
J1-DC+
Power supply positive, preset to 5 VDC, 1-A current limit.
J1-DC–
Power supply ground
J2-BAT+
Positive battery pack terminal
J2-BAT–
Negative battery pack terminal
J2-TS
NC
J2-BAT–
NC
J3-STAT1
External hardware if J4-EXT is jumpered (Not jumpered from factory)
J3-STAT2
External hardware if J5-EXT is jumpered (Not jumpered from factory)
J3-DC–
Return for J3 signals
J3-PG
External hardware if J6-EXT if jumpered (Not jumpered from factory)
JMP1 (Jumper)
LED connection
JMP2 (Jumper)
LED connection
JMP3 (Jumper)
LED connection (bq24085, bq24086, and bq24088). CE - without jumper defaults low - Charge Enable, with
Jumper - Charge Disable
JMP4 (Jumper)
TMR enable with jumper installed
Test Procedure Using Single-cell Li-ion Battery
Set up the evaluation board as previously described in Table 2 , making the necessary I/O connections
and jumper selections. Prior to test and evaluation, it is important to verify that the maximum IC power
dissipation (P(MAX) = 1.5 W) is not exceeded.
1. Turn on the power supply, which was preset to 5 VDC, and 1 A for the current-limit setting.
2. The bq24085/6/7/8 enters preconditioning mode if the battery is below the V(LOWV) threshold. In this
mode, the bq24085/6/7/8 precharges the battery with a low current (typically IO(CHG) /10 = 0.4A/10 =
40 mA) until the battery voltage reaches the V(LOWV) threshold or until the precharge timer expires. If
the timer expires, then the charge current is terminated and the bq24085/6/7/8 enters fault mode. Both
LEDs turn off when in fault mode. Toggling input power or battery replacement resets fault mode.
3. Once the battery voltage is above the V(LOWV) threshold, the battery enters fast-charge mode. This
EVM is programmed for 0.4 A of fast-charging current.
4. Once the battery reaches voltage regulation (4.2 V), the current tapers down as the battery reaches its
full capacity.
5. The battery remains at the fast charge mode until either the charge timer expires or the charge
termination current threshold is reached.
2
bq24085/6/7/8 Evaluation Module
SLUU305 – March 2008
Submit Documentation Feedback
www.ti.com
Test Summary
6. Once the charge terminates, J7 (TMR jumper) can be removed, putting the IC in LDO mode, and the
charger should turn on and regulate at 4.2 V or in constant current mode if the battery voltage drops
below 4.2 V. Replacing the jumper allows the IC to terminate properly.
Note:
Loads across the battery can affect termination.
7. If the battery discharges to the recharge threshold, the charger starts fast charging.
2.3
Alternative Test Procedures (Without Battery)
This are alternative methods of testing the EVM without a battery. These alternative test procedures
include:
• Four Quadrant Power Supply (Sinks or Source Current)
• Large Capacitor
• Dynamic Load Board
Because of the battery detection circuit, it is difficult to test the different charge phases without a battery
(using just resistors); the algorithm sinks and sources current and applies precharge and fast-charge
current depending on the mode it is in. Applying a load that would keep the voltage at 3.5 V (3.5 V/0.7 A)
would pull the output into precharge mode and keep it there during the battery detection algorithm, which
always occurs when the output is discharged to the refresh threshold. Once in precharge mode, a load
sufficient to allow the capacitor to charge to V(lowV) would allow the output to jump to voltage regulation
once the 0.7-A fast charge function is activated.
2.3.1
Four Quadrant Power Supply (Sinks or Source Current)
A source meter that can sink current can easily be adjusted to test each mode.
2.3.2
Large Capacitor
To briefly see each mode on a scope, connect a 1 mF capacitor in parallel with a 20 kΩ resistor on the
output to observe the power up and cycling between voltage regulation and fast charge via the refresh
threshold.
2.3.3
Dynamic Load Board
The circuit is adjusted to work with the displayed parts and their inherent thresholds. The sequence of the
test procedure is important due to the active battery detection circuit, refresh feature, precharge, and
fast-charge current levels (switching the load in and out in different modes has different results). No
damage should occur, but one might get different results than anticipated if the procedure is altered.
SLUU305 – March 2008
Submit Documentation Feedback
bq24085/6/7/8 Evaluation Module
3
www.ti.com
Test Summary
2.4
Required Equipment
a.
b.
c.
d.
Power Source: Current-limited 5-V laboratory power supply with its current limit set to 1 A ± 0.1 A
Two Fluke 75 digital multimeters (equivalent equipment or better)
Oscilloscope – TDS220 or better
Load test board shown in Figure 1
bq24085
+
Figure 1. Load Test Board
2.5
Test Equipment Setup
a.
b.
c.
d.
e.
2.6
Connect the load board to the BAT+ and BAT- terminals. Set SW1 through SW4 in the ON position.
Connect a voltage meter to the BAT+/BAT- output to monitor the output voltage range (0 to 5 V).
Set the lab supply for 5.1 V ± 0.1 VDC and a 1.0 ± 0.1 A current limit.
Turn off supply.
Connect the source supply to a current meter and to J1, noting polarity (may use an internal source
current meter, if it has 5% or better accuracy).
Test Procedure
1. Ensure that all Test Equipment Setup steps are performed. Switches should be in the ON position and
power source set to 5.1 V ± 0.1 VDC.
• bq24085 and bq24086—place shunts on pins 1 and 2 for jumpers JMP1, JMP2, and JMP3, JMP4.
• bq24087—place shunts on pins 1 and 2 for jumpers JMP1, JMP2, and JMP4. For JMP3, place
shunt on just one pin (do not short the pins).
2. Turn on the power source.
3. Verify output voltage, BAT+, charges up to between 2.5 V to 2.9 V and the red STAT1 LED (D1) and
green STAT2 LED light (all dash #s).
4. Verify the green PG LED (D3) lights for bq24085-001 and bq24086-002.
5. For bq24085 and bq24087, verify that J2-2 with respect to ground is less than 0.3 volts.
6. For bq24085, apply input voltage, J1-1 (+5 V) to J2-2, verify that charging stops (Iin or Ibat < 30 mA).
Remove 5 V from J2-2.
7. For bq24087, apply input voltage, J1-1 (+5 V) to J2-2, verify that charging continues. Remove 5 V from
J2-2.
8. For bq24087, apply shunt across pins 1 and 2 of JMP3, verify that charging stops (Iin or Ibat < 30 mA)
and STAT1 (D1) and STAT2 (D2) LEDs turn off. Remove JMP3 shunt and place on just one pin.
9. For bq24086, verify that J2-2 with respect to ground is between 2 V and 3 V.
10. Adjust the Input Voltage to 7.0±0.1 V. Verify charging stops (Iin or Ibat < 30 mA) stops for bq24085,
bq24086, and bq24087, plus continues (no change) for bq24088.
4
bq24085/6/7/8 Evaluation Module
SLUU305 – March 2008
Submit Documentation Feedback
www.ti.com
Test Summary
Note:
The bq24088 charge current may cycle on and off due to thermal cutoff. This is normal.
11.
12.
13.
14.
15.
16.
17.
18.
Open SW2 switch and close SW2 switch. Verify the green LED STAT2 (D2) turned off.
Verify output voltage, BAT+, settles between 3.1 V and 3.9 V.
Verify that the input current is between 0.3 A and 0.55 A.
Open SW3 switch.
Verify that the input current is between 100 mA and 150 mA.
Verify the output voltage, BAT+, is between 4.15 VDC and 4.25 VDC.
Open SW2 switch.
Verify, with a scope (250 ms/div, 1 V/div), that output, BAT+, charges and discharges between the
maximum value of 4.5 V and minimum value of 3 V (smaller range is typical 3.6 to 4.3), with a period
between 550ms and 850ms.
19. Verify that the LEDs flash between RED (D1) and GREEN (D2, mostly on green).
20. For bq24085 and bq24086, remove shunt JMP4 and verify that BAT+ is between 4.15 VDC and
4.25 VDC, plus the red LED (D1) lights.
21. For bq24085 and bq24086, install JMP4 shunt.
22. Close SW2 and SW3 switches. All switches should be closed.
23. Power down supply.
SLUU305 – March 2008
Submit Documentation Feedback
bq24085/6/7/8 Evaluation Module
5
www.ti.com
Schematic
3
Schematic
NOTE: C3 is optional and not installed.
Figure 2. EVM Schematic Diagram
6
bq24085/6/7/8 Evaluation Module
SLUU305 – March 2008
Submit Documentation Feedback
www.ti.com
Physical Layouts
4
Physical Layouts
This section provides the board layout and assembly drawings for the EVM, that include the top layer
(Figure 3), the bottom layer (Figure 4), and top assembly view (Figure 5) of the EVM.
Figure 3. Top Layer Routing
Figure 4. Bottom Layer Routing
SLUU305 – March 2008
Submit Documentation Feedback
bq24085/6/7/8 Evaluation Module
7
www.ti.com
Physical Layouts
Figure 5. Top Assembly View
8
bq24085/6/7/8 Evaluation Module
SLUU305 – March 2008
Submit Documentation Feedback
www.ti.com
Bill of Materials
5
Bill of Materials
HPA314A Bill of materials for bq24085, bq24086, bq24087, and bq24088 parts.
Table 3. HPA314A Bill of Materials
Ref
24085 24086 24087 24088 Des
Value
Description
Size
Part Number
MFR
1
1
1
1
C1
4.7 µF
Capacitor, Ceramic, 16 V,
X5R, 10%
0805
ECJ-2FB1C475K
Panasonic
1
1
1
1
C2
2.2 µF
Capacitor, Ceramic, 16 V,
X5R, 10%
0805
ECJ-2FB1C225K
Panasonic
1
1
1
1
C3
0.1 µF
Capacitor, Ceramic, 50 V,
X7R, 10%
0603
Std
Std
1
1
1
1
C4
0.01 µF
Capacitor, Ceramic, 50 V,
X7R, 10%
0603
Std
Std
1
1
1
1
D1
LTST-C190CKT
Diode, LED, Red, 2.1 V,
20 mA, 6-mcd
0603
LTST-C190CKT
Lite On
1
1
1
1
D2
LTST-C190GKT
Diode, LED, Green, 2.1 V,
20 mA, 6-mcd
0603
LTST-C190GKT
Lite On
1
1
0
1
D3
LTST-C190GKT
Diode, LED, Green, 2.1 V,
20 mA, 6-mcd
0603
LTST-C190GKT
Lite On
0
0
1
0
D3
0 Ohm
Resistor, Chip, 1/16W, 1%
0603
Std
Std
0.27 x
ED555/2DS
0.25 inch
OST
1
1
1
1
J1
ED555/2DS
Terminal Block, 2-pin, 6 A,
3.5 mm
1
1
1
1
J2
ED555/4DS
Terminal Block, 4-pin, 6-A,
3.5 mm
0.55 x
ED555/4DS
0.25 inch
OST
4
4
4
4
JMP1,
JMP2,
JMP3,
JMP4
PTC36SAAN
Header, Male 2-pin,
100 mil spacing,
(36-pin strip)
0.100
inch
x2
PTC36SAAN
Sullins
3
3
3
3
R1,
R2,
R5
1.5 kΩ
Resistor, Chip, 1/16W, 1%
0603
Std
Std
0
1
0
1
R3
1MΩ
Resistor, Chip, 1/16W, 1%
0603
Std
Std
1
1
1
1
R6
1MΩ
Resistor, Chip, 1/16W, 1%
0603
Std
Std
0
0
1
0
R9
1MΩ
Resistor, Chip, 1/16W, 1%
0603
Std
Std
1
1
1
1
R4
1.13 kΩ
Resistor, Chip, 1/16W, 1%
0603
Std
Std
1
1
1
1
R7
49.9 kΩ
Resistor, Chip, 1/16W, 1%
0603
Std
Std
1
1
1
1
R8
390 Ω
Resistor, Chip, 1/16W, 1%
0603
Std
Std
1
0
0
0
U1
BQ24085DRC
IC, 750 mA Single Chip,
Li Ion/Li POL, Charger
DRC10
BQ24085DRC
TI
0
1
0
0
U1
BQ24086DRC
IC, 750 mA Single Chip,
Li Ion/Li POL, Charger
DRC10
BQ24086DRC
TI
0
0
1
0
U1
BQ24087DRC
IC, 750mA Single Chip,
Li Ion/Li POL, Charger
DRC10
BQ24087DRC
TI
0
0
0
1
U1
BQ24088DRC
IC, 750mA Single Chip,
Li Ion/Li POL, Charger
DRC10
BQ24088DRC
TI
1
1
1
1
–
PCB,
1.75 In x 1.2 In x 0.031 In
PCB
Any
4
4
4
4
Shunt
Shunt, 100-mil, Black
929950-00
3M
6
0.1
References
bq24085/6/7 data sheet (SLUS784)
SLUU305 – March 2008
Submit Documentation Feedback
bq24085/6/7/8 Evaluation Module
9
EVALUATION BOARD/KIT IMPORTANT NOTICE
Texas Instruments (TI) provides the enclosed product(s) under the following conditions:
This evaluation board/kit is intended for use for ENGINEERING DEVELOPMENT, DEMONSTRATION, OR EVALUATION PURPOSES
ONLY and is not considered by TI to be a finished end-product fit for general consumer use. Persons handling the product(s) must have
electronics training and observe good engineering practice standards. As such, the goods being provided are not intended to be complete
in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including product safety and environmental
measures typically found in end products that incorporate such semiconductor components or circuit boards. This evaluation board/kit does
not fall within the scope of the European Union directives regarding electromagnetic compatibility, restricted substances (RoHS), recycling
(WEEE), FCC, CE or UL, and therefore may not meet the technical requirements of these directives or other related directives.
Should this evaluation board/kit not meet the specifications indicated in the User’s Guide, the board/kit may be returned within 30 days from
the date of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY SELLER TO BUYER
AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF
MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user indemnifies TI from all claims
arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all
appropriate precautions with regard to electrostatic discharge.
EXCEPT TO THE EXTENT OF THE INDEMNITY SET FORTH ABOVE, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR ANY
INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
TI currently deals with a variety of customers for products, and therefore our arrangement with the user is not exclusive.
TI assumes no liability for applications assistance, customer product design, software performance, or infringement of patents or
services described herein.
Please read the User’s Guide and, specifically, the Warnings and Restrictions notice in the User’s Guide prior to handling the product. This
notice contains important safety information about temperatures and voltages. For additional information on TI’s environmental and/or
safety programs, please contact the TI application engineer or visit www.ti.com/esh.
No license is granted under any patent right or other intellectual property right of TI covering or relating to any machine, process, or
combination in which such TI products or services might be or are used.
FCC Warning
This evaluation board/kit is intended for use for ENGINEERING DEVELOPMENT, DEMONSTRATION, OR EVALUATION PURPOSES
ONLY and is not considered by TI to be a finished end-product fit for general consumer use. It generates, uses, and can radiate radio
frequency energy and has not been tested for compliance with the limits of computing devices pursuant to part 15 of FCC rules, which are
designed to provide reasonable protection against radio frequency interference. Operation of this equipment in other environments may
cause interference with radio communications, in which case the user at his own expense will be required to take whatever measures may
be required to correct this interference.
EVM WARNINGS AND RESTRICTIONS
It is important to operate this EVM within the input voltage range of 4.4 V to 16 V and the output voltage range of 2.3 V to 4.4 V.
Exceeding the specified input range may cause unexpected operation and/or irreversible damage to the EVM. If there are questions
concerning the input range, please contact a TI field representative prior to connecting the input power.
Applying loads outside of the specified output range may result in unintended operation and/or possible permanent damage to the EVM.
Please consult the EVM User's Guide prior to connecting any load to the EVM output. If there is uncertainty as to the load specification,
please contact a TI field representative.
During normal operation, some circuit components may have case temperatures greater than 75°C. The EVM is designed to operate
properly with certain components above 100°C as long as the input and output ranges are maintained. These components include but are
not limited to linear regulators, switching transistors, pass transistors, and current sense resistors. These types of devices can be identified
using the EVM schematic located in the EVM User's Guide. When placing measurement probes near these devices during operation,
please be aware that these devices may be very warm to the touch.
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright 2008, Texas Instruments Incorporated
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements,
and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should
obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are
sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment.
TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard
warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where
mandated by government requirements, testing of all parameters of each product is not necessarily performed.
TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and
applications using TI components. To minimize the risks associated with customer products and applications, customers should provide
adequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right,
or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information
published by TI regarding third-party products or services does not constitute a license from TI to use such products or services or a
warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual
property of the third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied
by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive
business practice. TI is not responsible or liable for such altered documentation. Information of third parties may be subject to additional
restrictions.
Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all
express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not
responsible or liable for any such statements.
TI products are not authorized for use in safety-critical applications (such as life support) where a failure of the TI product would reasonably
be expected to cause severe personal injury or death, unless officers of the parties have executed an agreement specifically governing
such use. Buyers represent that they have all necessary expertise in the safety and regulatory ramifications of their applications, and
acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products
and any use of TI products in such safety-critical applications, notwithstanding any applications-related information or support that may be
provided by TI. Further, Buyers must fully indemnify TI and its representatives against any damages arising out of the use of TI products in
such safety-critical applications.
TI products are neither designed nor intended for use in military/aerospace applications or environments unless the TI products are
specifically designated by TI as military-grade or "enhanced plastic." Only products designated by TI as military-grade meet military
specifications. Buyers acknowledge and agree that any such use of TI products which TI has not designated as military-grade is solely at
the Buyer's risk, and that they are solely responsible for compliance with all legal and regulatory requirements in connection with such use.
TI products are neither designed nor intended for use in automotive applications or environments unless the specific TI products are
designated by TI as compliant with ISO/TS 16949 requirements. Buyers acknowledge and agree that, if they use any non-designated
products in automotive applications, TI will not be responsible for any failure to meet such requirements.
Following are URLs where you can obtain information on other Texas Instruments products and application solutions:
Products
Amplifiers
Data Converters
DSP
Clocks and Timers
Interface
Logic
Power Mgmt
Microcontrollers
RFID
RF/IF and ZigBee® Solutions
amplifier.ti.com
dataconverter.ti.com
dsp.ti.com
www.ti.com/clocks
interface.ti.com
logic.ti.com
power.ti.com
microcontroller.ti.com
www.ti-rfid.com
www.ti.com/lprf
Applications
Audio
Automotive
Broadband
Digital Control
Medical
Military
Optical Networking
Security
Telephony
Video & Imaging
Wireless
www.ti.com/audio
www.ti.com/automotive
www.ti.com/broadband
www.ti.com/digitalcontrol
www.ti.com/medical
www.ti.com/military
www.ti.com/opticalnetwork
www.ti.com/security
www.ti.com/telephony
www.ti.com/video
www.ti.com/wireless
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright © 2008, Texas Instruments Incorporated
