PRODUCT DATASHEET
AAT3688
BatteryManagerTM
General Description
The AAT3688 BatteryManager™ is a highly integrated single cell lithium-ion/polymer battery charger IC designed to operate with USB port inputs. It requires the minimum number of external components. The AAT3688 precisely regulates battery charge voltage and current for 4.2V lithium-ion/polymer battery cells. Depending on the USB port type, the AAT3688 charge current can be programmed for two separate levels up to 500mA. An optional Charge Reduction Loop is built in to allow users to charge the battery with available current from a USB port, while keeping the port voltage regulated. Battery temperature and charge state are fully monitored for fault conditions. In the event of an over-voltage or over-temperature failure, the device will automatically shut down, thus protecting the charging device, control system, and the battery under charge. Status monitor output pins are provided to indicate the battery charge status by directly driving two external LEDs. A serial interface output is available to report any one of 14 various status states to a microcontroller. The AAT3688 is available in a Pb-free, thermally-enhanced, space-saving 12-pin 3x3mm TDFN package and is rated over the -40°C to +85°C temperature range.
USB Port Lithium-Ion/Polymer Battery Charger
Features
• USB Charger ▪ Programmable up to 500mA Max • 4.0V to 5.5V Input Voltage Range • High Level of Integration With Internal: ▪ Charging Device ▪ Reverse Blocking Diode ▪ Current Sensing • Automatic Recharge Sequencing • Charge Reduction Loop for USB Charging • Battery Temperature Monitoring • Full Battery Charge Auto Turn-Off • Over-Voltage Protection • Emergency Thermal Protection • Power On Reset and Soft Start • Serial Interface Status Reporting • 12-Pin 3x3mm TDFN Package
Applications
• • • • • • • Bluetooth™ Headsets Cellular Telephones Digital Still Cameras Hand-Held PCs MP3 Players Personal Data Assistants (PDAs) Other Lithium-Ion/Polymer Battery-Powered Devices
Typical Application
Enable USB Input USB Hi/Lo Select
USB USBSEL USBH RSETH RSETL USBL BAT TS C2 10µF EN CHR
BATT+
AAT3688
GND
BATT-
DATA STAT1 STAT2
TEMP
Battery Pack
Serial Data
3688.2007.12.1.6
www.analogictech.com
1
PRODUCT DATASHEET
AAT3688 AAT3688
BatteryManagerTM
Pin Descriptions
Pin #
1 2 3 4 5 6 7 8 9 10 11 12 EP
USB Port Lithium-Ion/Polymer Battery Charger
Name
USB BAT GND CHR EN TS DATA STAT2 STAT1 USBSEL USBL USBH
Type
In In/Out Ground In/Out In In/Out In/Out Out Out In In/Out In/Out
Function
USB power supply input. Battery charging and sensing. Ground connection. Resistor divider to set USB voltage regulation for charge reduction mode. Leave this pin open for default 4.5V USB regulation point. Tie to USB pin to disable this function. Enable pin. Logic high enables the IC. Connect to 10kΩ NTC thermistor. Status report to microcontroller via serial interface, open-drain. Battery charge status indicator pin to drive an LED: active low, open-drain. Battery charge status indicator pin to drive an LED: active low, open-drain. When USB is present, use this pin to toggle between USBH and USBL charging levels. Connect resistor here to set charge current for low-current USB port. Connect resistor here to set charge current for high-current USB port. Exposed paddle (bottom); connect to GND directly beneath package.
Pin Configuration
TDFN33-12 (Top View)
USB BAT GND CHR EN TS
1 2 3 4 5 6
12 11 10 9 8 7
USBH USBL USBSEL STAT1 STAT2 DATA
2
www.analogictech.com
3688.2007.12.1.6
PRODUCT DATASHEET
AAT3688 AAT3688
BatteryManagerTM
Absolute Maximum Ratings1
Symbol
VP VP VN TJ TLEAD
USB Port Lithium-Ion/Polymer Battery Charger
Description
USB Input Voltage, VBAT Preconditioning Test VMIN > VBAT Yes Low Current Conditioning Charge USB Voltage Test VUSB < 4.5V
No
No Yes Current Phase Test VEOC > VBAT Current Charging Mode
Yes USB Loop Current Reduction in USB Charging Mode
No Yes Voltage Phase Test IBAT > ITERM No Charge Completed Voltage Charging Mode
12
www.analogictech.com
3688.2007.12.1.6
PRODUCT DATASHEET
AAT3688
BatteryManagerTM
Application Information
USB System Power Charging
The USB charge mode provides two programmable fast charge levels up to 500mA for each, USB high and USB low, USBH and USBL, respectively. The USBH or USBL modes may be externally selected by the USB select pin (USBSEL). When the USBSEL pin is connected to a logic high level, the USBH level will be active. Conversely, when USBSEL is pulled to a logic low level (ground), the USBL level will be used for fast charging. Typically USBH is set for 500mA and USBL is set for 100mA. However, these two USB charge levels may be user programmed to any level between 50mA and 500mA by selecting the appropriate resistor values for RSETH and RSETL. Refer to Table 1 for recommended RSETH and RSETL values for the desired USB input constant current charge levels.
USB Port Lithium-Ion/Polymer Battery Charger
Eq. 1: VUSBCHR = 2.0V ÷ where R11/R12 2 PDATA
N=1
N=2
N=3
First, the maximum power dissipation for a given situation should be calculated: Eq. 4: PD = [(VIN - VBAT) · ICC + (VIN · IOP)] Where: PD VIN VBAT ICC IOP = = = = Total Power Dissipation by the Device Input Voltage Level, VUSB Battery Voltage as Seen at the BAT Pin Maximum Constant Fast Charge Current Programmed for the Application = Quiescent Current Consumed by the Charger IC for Normal Operation
Example: For an application where the fast charge current is set to 500mA, VUSB = 5.0V and the worst case battery voltage at 3.0V, what is the maximum ambient temperature at which the thermal limiting will become active? Given: VADP VBAT ICC IOP TJ θJA = = = = = = 5.0V 3.0V 500mA 0.75mA 140°C 50°C/W
Next, the maximum operating ambient temperature for a given application can be estimated based on the thermal resistance of the 3x3mm TDFN package when sufficiently mounted to a PCB layout and the internal thermal loop temperature threshold. Eq. 5: TA = TJ - (θJA · PD) Where: TA = Ambient Temperature in Degrees C TJ = Maximum Device Junction Temperature Protected by the Thermal Limit Control PD = Total Power Dissipation by the Device θJA = Package Thermal Resistance in °C/W
Using Equation 4, calculate the device power dissipation for the stated condition: Eq. 6: PD = (5.0V - 3.0V)(500mA) + (5.0V · 0.75mA)
= 1.00375W
The maximum ambient temperature before the AAT3688 thermal limit protection will shut down charging can now be calculated using Equation 5: Eq. 7: TA = 140°C - (50°C/W · 1.00375W)
= 89.81°C
Therefore, under the stated conditions for this worst case power dissipation example, the AAT3688 will suspend charging operations when the ambient operating temperature rises above 89.81°C.
3688.2007.12.1.6
www.analogictech.com
17
PRODUCT DATASHEET
AAT3688
BatteryManagerTM
Capacitor Selection
Input Capacitor
In general, it is good design practice to place a decoupling capacitor between the VUSB pin and ground. An input capacitor in the range of 1μF to 22μF is recommended. If the source supply is unregulated, it may be necessary to increase the capacitance to keep the input voltage above the under-voltage lockout threshold during device enable and when battery charging is initiated. If the AAT3688 USB input is to be used in a system with an external power supply source rather than a USB port VBUS, such as a typical AC-to-DC wall adapter, then a CIN capacitor in the range of 10μF should be used. A larger input capacitor in this application will minimize switching or power bounce effects when the power supply is “hot plugged” in. Likewise, a 10μF or greater input capacitor is recommended for the USB input to help buffer the effects of USB source power switching noise and input cable impedance.
USB Port Lithium-Ion/Polymer Battery Charger
Output Capacitor
The AAT3688 only requires a 1μF ceramic capacitor on the BAT pin to maintain circuit stability. This value should be increased to 10μF or more if the battery connection is made any distance from the charger output. If the AAT3688 is to be used in applications where the battery can be removed from the charger, such as in the case of desktop charging cradles, an output capacitor greater than 10μF may be required to prevent the device from cycling on and off when no battery is present.
Printed Circuit Board Layout Considerations
For the best results, it is recommended to physically place the battery pack as close as possible to the AAT3688 BAT pin. To minimize voltage drops on the PCB, keep the high current carrying traces adequately wide. For maximum power dissipation of the AAT3688 3x3mm TDFN package, the metal substrate should be solder bonded to the board. It is also recommended to maximize the substrate contact to the PCB ground plane layer to further increase local heat dissipation. Refer to the AAT3688 evaluation board for a good layout example (see Figures 5 and 6).
18
www.analogictech.com
3688.2007.12.1.6
PRODUCT DATASHEET
AAT3688 AAT3688
BatteryManagerTM
AAT3688 Evaluation Board Layout
USB Port Lithium-Ion/Polymer Battery Charger
Figure 5: AAT3688 Evaluation Board Component Side Layout.
Figure 6: AAT3688 Evaluation Board Solder Side Layout.
AAT3688 Evaluation Board Schematic Diagram
ON/OFF J1
123
USBSEL J2
123
Mini-B GND ID D+ DVBUS
5 4 3 2 1
HI
LO
C2 TB1 USB GND
1 2
RED GRN LED D2 LED D1
R9 R3 R2 Open Open
1 5
10μF R5
10 8 9 7 11 12
U1
USB EN BAT
AAT3688
USBSEL STAT2 STAT1 DATA
R6 1.5K
1.5K
1.5K
BAT TS GND TB2
1 2 3
2
DATA
C1 10μF
4
CHR TS
USBL USBH
6
GND
3
R8 8.06K
R7 SW1 42.2K
R4 10K
R1 Open
TDFN33-12
3688.2007.12.1.6
www.analogictech.com
19
PRODUCT DATASHEET
AAT3688 AAT3688
BatteryManagerTM USB Port Lithium-Ion/Polymer Battery Charger
AAT3688 Evaluation Board Bill of Materials (BOM)
Quantity
1 1 1 1 2 1 1 2 1 3 1 1 1 1
Description
Test Pin Connecting Terminal Block, 2.54mm, 2 Pos Connecting Terminal Block, 2.54mm, 3 Pos USB 2.0 Receptacle, 5 Pos Capacitor, Ceramic, 10μF 6.3V 10% X5R 0805 Typical Red LED, Super Bright Typical Green LED Header, 3-Pin Resistor, 10kΩ 1/16W 5% 0603 SMD Resistor, 1.5kΩ 1/16W 1% 0603 SMD Resistor, 42.2kΩ 1/16W 1% 0603 SMD Resistor, 8.06kΩ 1/16W 1% 0603 SMD Switch Tact 6mm SPST H = 5.0mm AAT3688 USB Port Lithium-Ion/ Polymer Battery Charger
Desig.
DATA USB, GND BAT, GND, TS USB C1, C2 D1 D2 J1, J2 R4 R5, R6, R9 R7 R8 SW1 U1
Footprint
PAD TBLOK2 TBLOK3 USB-MINI-B 0805 1206LED 1206LED HEADER2MM-3 0603 0603 0603 0603 SWITCH TDFN33-12
Manufacturer
Mill-Max Phoenix Contact Phoenix Contact Hirose Electronic Co. Ltd. Murata Chicago Miniature Lamp Chicago Miniature Lamp Sullins Panasonic/ECG Panasonic/ECG Panasonic/ECG Panasonic/ECG ITT Industries/ C&K Div. AnalogicTech
Part Number
6821-0-0001-00-00-08-0 277-1274-ND 277-1273-ND H2959CT-ND 490-1717-1-ND CMD15-21SRC/TR8 CMD15-21VGC/TR8 6821-0-0001-00-00-08-0 P10KCFCT-ND P1.5KHTR-ND P42.2KHTR-ND P8.06KHCT-ND CKN9012-ND AAT3688IWP
20
www.analogictech.com
3688.2007.12.1.6
PRODUCT DATASHEET
AAT3688 AAT3688
BatteryManagerTM
Ordering Information
Package
TDFN33-12
USB Port Lithium-Ion/Polymer Battery Charger
Marking1
PKXYY
Part Number (Tape and Reel)2
AAT3688IWP-4.2-T1
All AnalogicTech products are offered in Pb-free packaging. The term “Pb-free” means semiconductor products that are in compliance with current RoHS standards, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. For more information, please visit our website at http://www.analogictech.com/pbfree.
Package Information3
Index Area Detail "A" 0.43 ± 0.05
0.1 REF 3.00 ± 0.05 2.40 ± 0.05 C0.3 0.45 ± 0.05
Pin 1 Indicator (optional)
3.00 ± 0.05
1.70 ± 0.05
Top View
Bottom View Detail "A"
0.75 ± 0.05
0.05 ± 0.05
Side View
All dimensions in millimeters.
1. XYY = assembly and date code. 2. Sample stock is generally held on part numbers listed in BOLD. 3. The leadless package family, which includes QFN, TQFN, DFN, TDFN and STDFN, has exposed copper (unplated) at the end of the lead terminals due to the manufacturing process. A solder fillet at the exposed copper edge cannot be guaranteed and is not required to ensure a proper bottom solder connection.
Advanced Analogic Technologies, Inc. 3230 Scott Boulevard, Santa Clara, CA 95054 Phone (408) 737-4600 Fax (408) 737-4611
© Advanced Analogic Technologies, Inc. AnalogicTech cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an AnalogicTech product. No circuit patent licenses, copyrights, mask work rights, or other intellectual property rights are implied. AnalogicTech reserves the right to make changes to their products or specifications or to discontinue any product or service without notice. Except as provided in AnalogicTech’s terms and conditions of sale, AnalogicTech assumes no liability whatsoever, and AnalogicTech disclaims any express or implied warranty relating to the sale and/or use of AnalogicTech products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. In order to minimize risks associated with the customer’s applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. Testing and other quality control techniques are utilized to the extent AnalogicTech deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed. AnalogicTech and the AnalogicTech logo are trademarks of Advanced Analogic Technologies Incorporated. All other brand and product names appearing in this document are registered trademarks or trademarks of their respective holders.
3688.2007.12.1.6
www.analogictech.com
0.23 ± 0.05
0.23 ± 0.05
21