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PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
General Description
The AAT3783 BatteryManagerTM is a single-cell LithiumIon (Li-Ion)/Li-Polymer battery charger IC, designed to operate from USB ports, AC adapter inputs, or from a charger adapter up to an input voltage of 6.5V. For increased safety, the AAT3783 also includes over-voltage input protection (OVP) up to 28V. The AAT3783 precisely regulates battery charge voltage and current for 4.2V Li-Ion/Polymer battery cells through an extremely low RDS(ON) switch. When charged from an adapter or a USB port, the battery charging current can be set by an external resistor up to 1A. In the case of an over-voltage condition in excess of 6.5V, a series switch opens preventing damage to the battery and charging circuitry. With the addition of an external resistor the OVP trip point can be programmed to a level other than the factory set value of 6.5V. In the case of an OVP condition a fault flag is activated. Battery charge state is continuously monitored for fault conditions. In the event of an over-current, battery overvoltage, short-circuit or over-temperature failure, the device will automatically shut down, thus protecting the charging device, control system and the battery under charge. A status monitor output pin is provided to indicate the battery charge status by directly driving an external LED. An open-drain power-source detection output (ADPP) is provided to report the power supply status. The AAT3783 comes in a thermally enhanced, spacesaving, Pb-free 16-pin 3x4 mm TDFN package and is specified for operation over the -40C to +85C temperature range.
Features
* USB or AC Adapter System Power Charger * Programmable from 100mA to 1A Max * 4.0V ~ 7.5V Input Voltage Range Over-Voltage Input Protection up to 28V * High Level of Integration with Internal: Charging Device Reverse Blocking Diode Current Sensing * Digital Thermal Regulation * Charge Current Programming (ISET) * Charge Termination Current Programming (TERM) * Charge Timer (CT) * Battery Temperature Sensing (TS) * TS Pin Open Detection * Automatic Recharge Sequencing * No Trickle Charge Option Available * Full Battery Charge Auto Turn Off / Sleep State / Charge Termination * Automatic Trickle Charge for Battery Pre-conditioning * Battery Over-Voltage and Over-Current Protection * Emergency Thermal Protection * Power On Reset * 16-pin 3x4mm TDFN Package
Applications
* * * * * * BluetoothTM Headsets, Headphones, Accessories Digital Still Cameras Mobile Phones MP3 Players Personal Data Assistants (PDAs) Other Li-Ion/Polymer Battery Powered Devices
Typical Application
VIN IN IN FLT OVP INCHR 2.2F STAT ADPP Enable Charging Enable OVP ENCHR ENOVP GND TERM ISET RSET RTERM CT TS CT Battery Pack TEMP BATS BAT BATT+
AAT3783
10F BATT-
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PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
Pin Descriptions
Pin Number
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15, 16
Name
INCHR BATS BAT TS ENOVP OVP FLT STAT ADPP CT ENCHR TERM GND ISET IN
Type
I/O I O I/O I I O O O I I I I/O I I
Function
Internal connection between the output of the OVP stage and the input of the battery charger. Decouple with 2.2F capacitor. Battery sense pin. Connect directly to the battery's + terminal. If not used, BATS must be connected to BAT. Connect to Lithium-Ion battery. Battery temperature sense pin. Active low enable for OVP stage. Over-voltage protection threshold pin. Leave open for the default 6.5V setting; connect to a resistor to adjust the OVP setting (see Application Information). Over-voltage fault flag, open drain. Charge status pin, open drain. Input power-good (USB port/adapter present indicator) pin, open-drain. Charge timer programming input pin (no timer if grounded). Active high enable pin (with internal pull-down) for charging circuitry. Charge termination current programming input pin (internal default 10% termination current if TERM is open). Connect to power ground. Charge current programming input pin. Input from USB port/ adapter connector.
Pin Configuration
TDFN34-16 (Top View)
INCHR BATS BAT TS ENOVP OVP FLT STAT
1 EP1 2 3 4 5 6 7 8 EP2
16 15 14 13 12 11 10 9
IN IN ISET GND TERM ENCHR CT ADPP
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PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
Absolute Maximum Ratings1
Symbol
VIN VINCHR VFLT VN TJ TLEAD
Description
IN continuous Charger IN continuous Fault flag continuous BAT, STAT, ADPP, EN, ISET, TS, ENOVP, OVP Operating Junction Temperature Range Maximum Soldering Temperature (at Leads)
Value
30 -0.3 to 7.5 -0.3 to +30 -0.3 to VINCHR + 0.3 -40 to 150 300
Units
V V V V C C
Thermal Information2
Symbol
JA PD
Description
Maximum Thermal Resistance (TDFN 3x4) Maximum Power Dissipation
Value
50 2
Units
C/W W
1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at conditions other than the operating conditions specified is not implied. Only one Absolute Maximum Rating should be applied at any one time. 2. Mounted on a FR4 board.
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PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
Electrical Characteristics1
VIN = 5V, TA = -40C to +85C; unless otherwise noted, typical values are at TA = 25C. Symbol Description Conditions Min Typ Max
28 7.5 3 60 30 4 6.5 3 150 VIN > VUVLO Charge Current = 100mA, ENOVP = 0V, ENCHG = VIN VBAT = 4.25V, ENOVP = ENCHG = 0V2 VBAT = 4V, ENOVP = VIN 4.158 (Option available for no trickle charge) 2.5 60 0.5 0.4 0.4 4.20 0.5 2.6 VBAT_EOC 0.1 100 -10 2 800 0.2 5 TERM Pin Open RTERM = 13.3 k, ICH_CC 800mA Battery Charging Device RDS(ON) Total ON Resistance (IN to BAT) VIN = 5V, IOUT = 1A 5 8 10 10 10 550 15 15 12 1000 10 150 1 1 2 4.242 2.7 4 50 8
Units
V V V mV A A V V mV mV mA A A V % V V mA % V V %
Operation VIN_MAX Input Over-Voltage Protection Range VIN Normal Operating Input Voltage Range Over-Voltage Protection Under-Voltage Lockout Threshold VUVLO UVLO Hysteresis IQ ISD(OFF) Operating Quiescent Current Shutdown Supply Current
4.0 Rising Edge VIN = 5V, ENOVP = 0V, IOUT = 0, ENCHG = 0V ENOVP = VIN = 5.5V, VOUT = 0V, ENCHG = 0V Rising Edge, OVP = Not Connected Rising Edge
VOVPT Over-Voltage Protection Trip Voltage Battery Charger Under-Voltage Lockout Threshold VUVLO UVLO Hysteresis Adapter Present Indicator Threshold VADPP_TH Voltage, VIN - VBAT IOP Operating Current
ISHUTDOWN Shutdown Mode Current IBAT Leakage Current from BAT Pin Voltage Regulation VBAT_EOC Output Charge Voltage Regulation VCH/VCH Output Charge Voltage Tolerance VMIN Preconditioning Voltage Threshold VRCH Battery Recharge Voltage Threshold
Current Regulation ICC_RANGE Charge Current Programmable Range ICH_CC Constant-Current Mode Charge Current VISET ISET Pin Voltage KISET Charge Current Set Factor: ICH_CC/IISET VTERM TERM Pin Voltage ICH_TRK ICH_TERM Trickle Charge Current Charge Termination Threshold Current
VBAT = 3.6V Constant Current Mode, VBAT = 3.6V RTERM = 13.3k
ICH_CC % ICH_CC % m
1. The AAT3783 is guaranteed to meet performance specifications over the -40C to +85C operating temperature range and is assured by design, characterization and correlation with statistical process controls. 2. Current into charge.
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PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
Electrical Characteristics1
VIN = 5V, TA = -40C to +85C; unless otherwise noted, typical values are at TA = 25C. Symbol Description Conditions Min
1.6 STAT Pin Sinks 4mA ADPP Pin Sinks 4mA FLT Pin Sinks 1mA From De-assertion of OV From Assertion of OV VIN Rise to 7V from 5V in 1ns Charging current = 500mA, CINCHR = 1F Charging current = 500mA, CINCHR = 1F Charging current = 500mA, CINCHR = 1F 5 10 1 1 10 1 6 4.4 105 3 25 3 75 331 25 2.39 25 115 85 100 140 15 0.4 0.4 8 0.4 8 0.4 5 15
Typ
Max
Units
V V V mA V mA V mA ms s s ms ms s V % ICH_CC Hour Minute Hour A mV V mV C C C C
Logic Control Input High Threshold VEN(H) VEN(L) Input Low Threshold VSTAT Output Low Voltage ISTAT STAT Pin Current Sink Capability VADDP Output Low Voltage ADPP Pin Current Sink Capability IADPP VFLT Output Low Voltage IFLT FLT Pin Current Sink Capability TBLK_FLT FLT Blanking Time TD_FLT FLT Assertion Delay Time from Over-Voltage TRESP_OV Over-Voltage Response Time TOVPON TOVPR TOVPOFF OVP Turn-On Delay Time OVP Turn-On Rise Time OVP Turn-Off Delay Time
Battery Protection VBOVP IBOCP TC TK TV ITS TS1 TS2 TLOOP_IN TLOOP_OUT TREG TSHDN Battery Over-Voltage Protection Threshold Battery Over-Current Protection Threshold Trickle Plus Constant Current Mode Timeout Trickle Timeout Constant Voltage Mode Time Out Current Source from TS Pin TS Hot Temperature Fault TS Cold Temperature Fault Thermal Loop Entering Threshold Thermal Loop Exiting Threshold Thermal Loop Regulation Chip Thermal Shutdown Temperature Threshold Hysteresis CCT = 100nF, VIN = 5V CCT = 100nF, VIN = 5V CCT = 100nF, VIN = 5V Threshold Hysteresis Threshold Hysteresis 69 316 2.30
81 346 2.48
1. The AAT3783 is guaranteed to meet performance specifications over the -40C to +85C operating temperature range and is assured by design, characterization and correlation with statistical process controls.
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PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
Typical Characteristics
Constant Charging Current vs. Set Resistor Values
10000 1200
Constant Charging Current (mA)
Battery Charging Current vs. Battery Voltage
Charging Current (mA) RSET = 1.62k
1000 800 600 400 200 0 2.5
1000
RSET = 2k RSET = 3.24k RSET = 8.06k
100
10
1 1 10 100 1000
2.7
2.9
3.1
3.3
3.5
3.7
3.9
4.1
4.3
4.5
RSET (mA)
Battery Voltage (V)
End of Charge Regulation Tolerance vs. Input Voltage
(VBAT_EOC = 4.2V)
0.15
End of Charge Voltage vs. Temperature
4.23 4.22 4.21 4.20 4.19 4.18 4.17
VBAT_EOC/VBAT_EOC (%)
0.1 0.05 0 -0.05 -0.1 -0.15 4.5
VEOC (%)
5
5.5
6
6.5
7
7.5
-40
-15
10
35
60
85
Input Voltage (V)
Temperature (C)
Battery Recharge Voltage Threshold vs. Temperature
4.16 140 120
Preconditioning Charge Current vs. Input Voltage
Recharge Voltage (%)
4.14 4.12 4.1 4.08 4.06 4.04 -40
ICH_TRK (mA)
100 80 60 40 20
RSET = 1.62k
RSET = 2k RSET = 3.24k RSET = 8.06k
0 -15 10 35 60 85 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5
Temperature (C)
Input Voltage (V)
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PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
Typical Characteristics
Preconditioning Charge Current vs. Temperature
(RSET = 8.06k; ICH_CC = 200mA) Preconditioning Charge Current (mA)
23 22 21 2.66 2.64 2.62
Preconditioning Voltage Threshold vs. Temperature
VMIN (V)
20 19 18 17 -40
2.60 2.58 2.56 2.54
-15
10
35
60
85
-40
-15
10
35
60
85
Temperature (C)
Temperature (C)
Constant Charging Current vs. Input Voltage
Constant Charging Current (mA) (RSET = 1.62k)
1200 800
Total Resistance vs. Input Voltage
(IN to BAT)
VBAT = 3.3V
1100
750
RDS(ON) (m)
VBAT = 3.6V
1000
700 650 600 550 500
85C 25C
900
VBAT = 3.9V VBAT = 4.1V
800
-40C
450 6 6.5 7 7.5 400 3.6 3.8 4 4.2 4.4 4.6 4.8 5
700 4 4.5 5 5.5
Input Voltage (V)
Input Voltage (V)
Temperature Sense Too Hot Threshold vs. Temperature
Temperature Sense Threshold Voltage (TS1) (mV) Temperature Sense Threshold Voltage (TS2) (mV)
339 337 335 333 331 329 327 325 -40
Temperature Sense Too Cold Threshold vs. Temperature
2.400
2.395
2.390
2.385
2.380
-15
10
35
60
85
2.375 -40
-15
10
35
60
85
Temperature (C)
Temperature (C)
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PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
Typical Characteristics
Temperature Sense Output Current vs. Temperature
78 1.0 0.9
CT Pin Capacitance vs. Counter Timeout
Capacitance (F)
76
0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 Preconditioning + Constant Current Timeout or Constant Voltage Timeout Preconditioning Timeout
ITS (mV)
74
72
70
68 -40 -15 10 35 60 85
0.0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
Temperature (C)
Time (h)
Operating Current vs. ISET Resistor
1.6 1.4 1.2 Constant current mode
Termination Current to Constant Current Ratio vs. Termination Resistance
50
IOP (mA)
1.0 0.8 0.6 0.4 0.2 0.0 1 10 100 1000 Preconditioning mode
ICH_TERM/ICH_CC (%)
40
30
20
10
0 0 10 20 30 40 50 60
RSET (k)
ITERM Resistance (k)
Input Low Threshold vs. Input Voltage
1.6 1.4 1.2 1.0 0.8 0.6 0.4 4 4.5 5 5.5 6 6.5 7 7.5 1.6 1.4 1.2 1.0 0.8 0.6 0.4
Input High Threshold vs. Input Voltage
VEN(H) (V)
VEN(L) (V)
-40C
25C
-40C 85C
25C
85C
4
4.5
5
5.5
6
6.5
7
7.5
Input Voltage (V)
Input Voltage (V)
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PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
Typical Characteristics
FLT Blanking Time
12 10 0.05
OVP Trip Point vs. Temperature
Input Voltage (V)
8 6 4 2 0 -2 -4 6 4 2 0
VOVPTRIP Error (%)
0.00
FLT Voltage (V)
-0.05
-0.10
-0.15
-0.20 -40
-15
10
35
60
85
Time (2ms/div)
Temperature (C)
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PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
Functional Block Diagram
INCHR
IN IN OVP
Over-Current Protection
Reverse Blocking
BAT
CV/ PreCharge Current Compare
OVP Sense and Control
BAT S
ENOVP FLT
Constant Current
Charge Control
UVLO
ADPP
Power Detection
Over Temp. Protect
Thermal Loop
ISET TERM ENCHR GND
Charge Status
STAT CT TS
Functional Description
The AAT3783 is a high performance battery charger designed to charge single cell Lithium-Ion or Polymer batteries with up to 1000mA of current from an external power source. It is a stand-alone charging solution, with just one external component required (two more for options) for complete functionality. Also included is input voltage protection (OVP) to up to +28V. OVP consists of a low resistance P-channel MOSFET in series with the charge control MOSFET, and also consists of under-voltage lockout protection, over-voltage monitor, and fast shut-down circuitry with a fault output flag.
Battery Preconditioning
Battery charging commences only after the AAT3783 checks several conditions in order to maintain a safe charging environment. The input supply must be above the minimum operating voltage (VUVLO) and the enable pin must be high. When the battery is connected to the BAT pin, the AAT3783 checks the condition of the battery and determines which charging mode to apply. If the battery voltage is below the preconditioning voltage threshold, VMIN, then the AAT3783 begins preconditioning the battery cell (trickle charging) by charging at 10% of the programmed constant current. For example, if the programmed current is 500mA, then the preconditioning mode (trickle charge) current is 50mA. Battery cell preconditioning (trickle charging) is a safety precaution for deeply discharged cells and will also reduce the power dissipation in the internal series pass MOSFET when the input-output voltage differential is at the greatest potential.
Battery Charging Operation
Figure 1 illustrates the entire battery charging profile or operation, which consists of three phases: 1. Preconditioning (Trickle) Charge 2. Constant Current Charge 3. Constant Voltage Charge
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PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
Preconditioning Trickle Charge Phase Charge Complete Voltage Regulated Current I = Max CC Constant Current Charge Phase Constant Voltage Charge Phase
Constant Current Mode Voltage Threshold
Trickle Charge and Termination Threshold
I = CC / 10
Figure 1: Current vs. Voltage Profile during Charging Phases.
Constant Current Charging
Battery cell preconditioning continues until the battery voltage reaches the preconditioning voltage threshold, VMIN. At this point, the AAT3783 begins constant current charging. The current level for this mode is programmed using a single resistor from the ISET pin to ground. The programmed current can be set at a minimum 100mA up to a maximum of 1A.
Thermal Considerations
The actual maximum charging current is a function of the charge adapter input voltage, the battery charge state at the moment of charge, the ambient temperature, and the thermal impedance of the package. The maximum programmable current may not be achievable under all operating parameters.
Constant Voltage Charging
Constant current charging will continue until such time that the battery voltage reaches the voltage regulation point, VBAT_EOC. When the battery voltage reaches VBAT_EOC, the AAT3783 will transition to constant voltage mode. The regulation voltage is factory programmed to a nominal 4.2V and will continue charging until the charge termination current is reached.
Over-Voltage Protection
In normal operation, a P-channel MOSFET acts as a slew-rate controlled load switch, connecting and disconnecting the power supply from IN to INCHR. A low resistance MOSFET is used to minimize the voltage drop between the voltage source and the charger and to reduce the power dissipation. When the voltage on the input exceeds the over-voltage trip point (internally set by the factory or externally programmed by a resistor connected to the OVP pin), the device immediately turns off the internal P-channel FET which disconnects the charger from the abnormal input voltage, therefore preventing any damage to the charger. Simultaneously, the fault flag is raise, alerting the system. If an over-voltage condition is applied at the time of the device enable, then the switch will remain OFF.
Charge Status Output
The AAT3783 provides battery charge status via a status pin. This pin is internally connected to an N-channel open-drain MOSFET, which can be used drive an external LED. The status pin can indicate the following conditions: Event Description
No battery charging activity Battery charging via adapter or USB port Charging completed
STATUS
OFF ON OFF
OVP Under-Voltage Lockout (UVLO)
The AAT3783 OVP circuitry has a fixed 3V under-voltage lockout level (UVLO). When the input voltage is less than the UVLO level, the MOSFET is turned off. 100mV of hysteresis is included to ensure circuit stability.
Table 1: LED Status Indicator.
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PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
Over-Current Protection
The AAT3783 over-current protection provides faultcondition protection that limits the charge current to approximately 1.6A under all conditions, even if the ISET pin gets shorted to ground.
Enable / Disable
The AAT3783 provides an enable function to control the OVP stage and charger on and off independently. ENOVP is an active-low enable input. ENOVP is driven low, connected to ground, or left floating for normal device operation. Taking ENOVP high turns off the MOSFET of the OVP stage. In the case of an over-voltage or UVLO condition, toggling ENOVP will not override the fault condition and the switch will remain off.
FLT Blanking Time
The FLT output is an active-low open-drain fault (OV) reporting output. A pull-up resistor should be connected from FLT to the logic I/O voltage of the host system. FLT will be asserted immediately an over-voltage fault occurs (only about a 1s inherited internal circuit delay). A 10ms blanking is applied to the FLT signal prior to deassertion.
OVP Turn-On Delay Time
On initial power-up, if VIN < UVLO or if VOVP > 6.5V the PMOS is held off. If UVLO < VIN, VOVP < 6.5V, and ENOVP is low, the device enters startup after a 10ms internal delay.
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PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
System Operation Flow Chart
Power On Sleep Sleep Reset Mode Mode ADP Voltage Power Input S Voltage ADP > V ADPP VIN>VUVLO No
Yes
Enable Power Select OVP?
No
ENOVP = Yes
OVP Condition Monitoring VIN > 6.5V?
No
Shut Down Disconnect Input Shut Down from charger Mode Mode
ENCHR = Yes
Fault Fault Condition Monitoring Power Select OV, OT, VTS1Yes
Shutdown Shut Down Shut Down Mode Mode Mode
Expire
Charger Timer Shut Down Shut Down Control Mode Mode
Preconditioning Test VMIN>VBAT V >V
MIN BAT
Yes
Preconditioning Shut Down Shut Down (Trickle Charge) Mode Mode
Enable
No
No Recharge Test VV > V BAT RCH RCH BAT Yes
Current Phase Test VIN>VBAT_EOC
Yes
Constant Current Shut Down Shut Down Charge Mode Mode Mode
V >V CH BAT No
Device Temp. No Device Temp. Monitor Monitor >110 TJ >115 C Yes
Thermal Loop Shut Down Shut Down Current Reduction Mode In C.C. Mode Mode
Voltage Phase Test IBAT>ITERM
Yes
Constant Voltage Shut Down Shut Down Charge Mode Mode Mode
IBAT MIN >I No
Charge Charge Completed Completed
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PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
Application Information
Programming the Over-Voltage Protection Trip Point
The default over-voltage protection trip point of the AAT3783 is set to 6.5V by the factory. However, the over-voltage protection trip point can be programmed from 3.8V to 7.5V by the user with one external resistor, either R5 or R6. The placement of R5 is between IN and OVP. The placement of R6 is between OVP and GND. Table 2 summarizes resistor values for various overvoltage protection trip points. Use 1% tolerance metal film resistors for programming the desired OVP trip point. R6 (K)
short 0.499 1.3 3.01 open open open open open
BATS pin may be terminated to the BAT pin using a 10k resistor. Under normal operation, the connection to the battery terminal will be close to 0; if the BATS connection becomes an open circuit, the 10k resistor will provide feedback to the BATS pin from the BAT connection with a voltage sensing accuracy loss of 1mV or less.
Constant Charge Current
The constant current mode charge level is user programmed with a set resistor placed between the ISET pin and ground. The accuracy of the constant charge current, as well as the preconditioning trickle charge current, is dominated by the tolerance of the set resistor used. For this reason, a 1% tolerance metal film resistor is recommended for the set resistor function. The constant charge current levels from 100mA to 1A may be set by selecting the appropriate resistor value from Table 3. Constant Charging Current (mA)
10 20 50 100 200 300 400 500 600 700 800 900 1000
R5 (K)
open open open open open 4.99 2.49 1.0 short
VOVP_TRIP POINT (V)
7.5 7.25 7.0 6.75 6.5 5.5 5.0 4.5 3.87
Set Resistor Value (k)
162 80.6 32.4 16 8.06 5.36 4.02 3.24 2.67 2.26 2 1.78 1.62
Table 2: Programming OVP Trip Point for AAT3783 with One Resistor.
Battery Connection and Battery Voltage Sensing
Battery Connection (BAT)
Constant Charging Current (mA)
A single cell Li-Ion/Polymer battery should be connected between the BAT pin and ground.
Table 3: RSET Values.
10000
Battery Voltage Sensing (BATS)
The BATS pin is provided to employ an accurate voltage sensing capability to measure the positive terminal voltage at the battery cell being charged. This function reduces measured battery cell voltage error between the battery terminal and the charge control IC. The AAT3783 charge control circuit will base charging mode states upon the voltage sensed at the BATS pin. The BATS pin must be connected to the battery terminal for correct operation. If the battery voltage sense function is not needed, the BATS pin should be terminated directly to the BAT pin. If there is concern of the battery sense function inadvertently becoming an open circuit, the
1000
100
10
1 1 10 100 1000
RSET (k)
Figure 2: Constant Charging Current vs. Set Resistor Values.
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PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
Charge Termination Current
The charge termination current ICH_TERM can be programmed by connecting a resistor from TERM to GND: Mode
Trickle Charge (TC) Time Out Trickle Charge (TC) + Constant Current (CC) Mode Time Out Constant Voltage (CV) Mode Time Out
Time
25 minutes 3 hours 3 hours
ICH_TERM =
Where:
15A * RTERM * ICH_CC 2V
Table 4: Summary for a 0.1F Ceramic Capacitor Used for the Timing Capacitor. The CT pin is driven by a constant current source and will provide a linear response to increase in the timing capacitor value. Thus, if the timing capacitor were to be doubled from the nominal 0.1F value, the time-out periods would be doubled. If the programmable watchdog timer function is not needed, it can be disabled by terminating the CT pin to ground. The CT pin should not be left floating or un-terminated, as this will cause errors in the internal timing control circuit. The constant current provided to charge the timing capacitor is very small, and this pin is susceptible to noise and changes in capacitance value. Therefore, the timing capacitor should be physically located on the printed circuit board layout as close as possible to the CT pin. Since the accuracy of the internal timer is dominated by the capacitance value, a 10% tolerance or better ceramic capacitor is recommended. Ceramic capacitor materials, such as X7R and X5R types, are a good choice for this application.
ICH_TERM = Charge termination current level ICH_CC = Programmed fast charge constant current level RTERM = TERM resistor value If the TERM pin is left open, the termination current will set to 10% of the constant charging current as the default value. When the charge current drops to the defaulted 10% of the programmed charge current level or programmed terminated current in the constant voltage mode, the device terminates charging and goes into a sleep state. The charger will remain in this sleep state until the battery voltage decreases to a level below the battery recharge voltage threshold (VRCH). Consuming very low current in sleep state, the AAT3783 minimizes battery drain when it is not charging. This feature is particularly useful in applications where the input supply level may fall below the battery charge or under-voltage lockout level. In such cases where the AAT3783 input voltage drops, the device will enter sleep state and automatically resume charging once the input supply has recovered from the fault condition.
Battery Over-Voltage Protection
An over-voltage event is defined as a condition where the voltage on the BAT pin exceeds the maximum battery charge voltage and is set by the over-voltage protection threshold (VBOVP). If an over-voltage condition occurs, the AAT3783 charge control will shut down the device until the voltage on the BAT pin drops below VOVP. The AAT3783 will resume normal charging operation after the over-voltage condition is removed.
Protection Circuitry
Programmable Watchdog Timer
The AAT3783 contains a watchdog timing circuit to shut down charging functions in the event of a defective battery cell not accepting a charge over a preset period of time. Typically, a 0.1F ceramic capacitor is connected between the CT pin and ground. When a 0.1F ceramic capacitor is used, the device will time out a shutdown condition if the trickle charge mode exceeds 25 minutes and a combined trickle charge plus constant current mode of 3 hours. When the device transitions to the constant voltage mode, the timing counter is reset and will time out after an additional 3 hours if the charge current does not drop to the charge termination level.
Battery Temperature Monitoring
In the event of a battery over-temperature condition, the charge control will turn off the internal pass device. After the system recovers from a temperature fault, the device will resume charging operation. The AAT3783 checks battery temperature before starting the charge cycle, as well as during all stages of charging. This is accomplished by monitoring the voltage at the TS pin. This system is intended for use with negative temperature coefficient thermistors (NTC) which are typically integrated into the battery package. Most of the commonly used NTC therm-
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PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
istors in battery packs are approximately 10k at room temperature (25C). The TS pin has been specifically designed to source 75A of current to the thermistor. The voltage on the TS pin resulting from the resistive load should stay within a window of 331mV to 2.39V. If the battery becomes too hot during charging due to an internal fault or excessive constant charge current, the thermistor will heat up and reduce in value, pulling the TS pin voltage lower than the TS1 threshold, and the AAT3783 will stop charging until the condition is removed, when charging will be resumed. If the use of the TS pin function is not required by the system, it should be terminated to ground using a 10k resistor. Alternatively, on the AAT3783, the TS pin may be left open.
Thermal Considerations and High Output Current Applications
The AAT3783 is designed to deliver a continuous charging current. The limiting characteristic for maximum safe operating charging current is its package power dissipation. Many considerations should be taken into account when designing the printed circuit board layout, as well as the placement of the IC package in proximity to other heat generating devices in a given application design. The ambient temperature around the IC will also have an effect on the thermal limits of a battery charging application. The maximum limits that can be expected for a given ambient condition can be estimated by the following discussion. First, the maximum power dissipation for a given situation should be calculated:
Over-Temperature Shutdown
The AAT3783 has a thermal protection control circuit which will shut down charging functions should the internal die temperature exceed the preset thermal limit threshold. Once the internal die temperature falls below the thermal limit, normal operation will resume the previous charging state.
PD(MAX) =
Where: PD(MAX) = JA = TJ = TA =
(TJ(MAX) - TA) JA
Digital Thermal Loop Control
Due to the integrated nature of the linear charging control pass device for the adapter mode, a special thermal loop control system has been employed to maximize charging current under all operation conditions. The thermal management system measures the internal circuit die temperature and reduces the fast charge current when the device exceeds a preset internal temperature control threshold. Once the thermal loop control becomes active, the fast charge current is initially reduced by a factor of 0.44. The initial thermal loop current can be estimated by the following equation:
Maximum Power Dissipation (W) Package Thermal Resistance (C/W) Thermal Loop Entering Threshold (C) [115C] Ambient Temperature (C)
Figure 3 shows the relationship of maximum power dissipation and ambient temperature of AAT3783.
2.5
2
PD(MAX) (W)
1.5
1
0.5
ITLOOP = ICH_CC * 0.44
The thermal loop control re-evaluates the circuit die temperature every three seconds and adjusts the fast charge current back up in small steps to the full fast charge current level or until an equilibrium current is discovered and maximized for the given ambient temperature condition. The thermal loop controls the system charge level; therefore, the AAT3783 will always provide the highest level of constant current in the fast charge mode possible for any given ambient temperature condition.
0 0 25 50 75 100
TA (C)
Figure 3: Maximum Power Dissipation Before Entering Digital Thermal Loop. Next, the power dissipation can be calculated by the following equation:
PD = [(VIN - VBAT) * ICH + (VIN * IOP)]
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PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
Where: PD VIN VBAT ICH IOP = = = = Total Power Dissipation by the Device Input Voltage Battery Voltage as Seen at the BAT Pin Constant Charge Current Programmed for the Application = Quiescent Current Consumed by the Charger IC for Normal Operation [0.4mA] no specific capacitor equivalent series resistance (ESR) requirement for CIN. However, for higher current operation, ceramic capacitors are recommended for CIN due to their inherent capability over tantalum capacitors to withstand input current surges from low impedance sources such as batteries in portable devices. Typically, 50V rated capacitors are required for most of the application to prevent any surge voltage. Ceramic capacitors selected as small as 1210 are available which can meet these requirements. Other voltage rating capacitor can also be used for the known input voltage application.
By substitution, we can derive the maximum charge current before reaching the thermal limit condition (thermal loop). The maximum charge current is the key factor when designing battery charger applications.
Charger Input Capacitor
(PD(MAX) - VIN * IOP) ICH(MAX) = VIN - VBAT (TJ(MAX) - TA) - V * I IN OP JA ICH(MAX) = VIN - VBAT
In general, the worst condition is the greatest voltage drop across the charger IC, when battery voltage is charged up to the preconditioning voltage threshold and before entering thermal loop regulation. Figure 4 shows the maximum charge current in different ambient temperatures.
1000
A 2.2F decoupling capacitor is recommended to be placed between INCHR and GND.
Charger Output Capacitor
The AAT3783 only requires a 1F ceramic capacitor on the BAT pin to maintain circuit stability. This value should be increased to 10F or more if the battery connection is made any distance from the charger output. If the AAT3783 is used in applications where the battery can be removed from the charger, such as with desktop charging cradles, an output capacitor greater than 10F may be required to prevent the device from cycling on and off when no battery is present.
TA = 45C
800
TA = 25C
Printed Circuit Board Layout Recommendations
For proper thermal management and to take advantage of the low RDS(ON) of the AAT3783, a few circuit board layout rules should be followed: VIN and VOUT should be routed using wider than normal traces, and GND should be connected to a ground plane. To maximize package thermal dissipation and power handling capacity of the AAT3783 DFN34 package, solder the exposed paddle of the IC onto the thermal landing of the PCB, where the thermal landing is connected to the ground plane. This AAT3783 has two exposed paddles (EP1 and EP2). EP1 is connected to INCHR (pin 1) and EP2 is connected to GND (pin 13). DO NOT make one whole thermal landing! If heat is still an issue, multi-layer boards with dedicated ground planes are recommended. Also, adding more thermal vias on the thermal landing would help the heat being transferred to the PCB effectively.
ICC_MAX (mA)
600
400
200
TA = 60C
0 4 4.5 5 5.5
TA = 85C
6 6.5 7 7.5
VIN (V)
Figure 4: Maximum Charging Current Before the Digital Thermal Loop Becomes Active.
Input Capacitor
A 1F or larger capacitor is typically recommended for CIN. CIN should be located as close to the device VIN pin as practically possible. Ceramic, tantalum, or aluminum electrolytic capacitors may be selected for CIN. There is
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PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
INCHR
INCHR JP1 Enable JP3
+5V
Red LED D1 U1 R7 6k
7 5 15 16 6 11
R3 (open)
Red LED Green LED D2 D3 R8 1.5k R9 1.5k
1 2 3
4V - 7.5V VIN GND
2 1
R5 (open) C1 1F R6 (open)
FLT ENOVP IN IN OVP ENCHR INCHR GND
AAT3783
ADPP STAT BATS BAT TS TERM ISET CT
9 8 2 3 4 12 14 10
GND BAT TS
INCHR
INCHR C2 2.2F JP2 EN_CHR
1 13
C3 10F R1 1.62k R2 13.3k R4 10k
C4 0.1F
C1 1206 X7R 1F 50V GRM31MR71H105KA88 (C1 1206 X7R 2.2F 50V GRM31CR71H225KA88L) (C1 1210 X7R 4.7F 50V GRM32ER71H475KA88L) C2 0805 X5R 2.2F 10V GRM188R61A225KE34 C3 0805 X7R 10F 10V GRM21BR71A106KE51L
Figure 5: AAT3783 Evaluation Board Schematic. Component
U1 R1 R2 R4 R7 R8, R9 C1 C2 C3 C4 JP1, JP2, JP3 D1, D2 D3
Part#
AAT3783IRN Chip Resistor Chip Resistor Chip Resistor Chip Resistor Chip Resistor GRM31MR71H105KA88 GRM188R61A225KE34 GRM21BR71A106KE51L GRM188R71E104KA01 PRPN401PAEN CMD15-21SRC/TR8 CMD15-21VGC/TR8
Description
1A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection; TDFN Package 1.62K, 1%, 1/4W; 0603 13.3K, 1%, 1/4W; 0603 10K, 5%, 1/4W; 0603 6K, 5%, 1/4W; 0603 1.5K, 5%, 1/4W; 0603 CER 1F 50V 10% X7R 1206 CER 2.2F 10V 10% X5R 0805 CER 10F 10V 10% X7R 0805 CER 0.1F 25V 10% X7R 0603 Conn. Header, 2mm zip Red LED; 1206 Green LED; 1206
Manufacturer
AnalogicTech Vishay Vishay Vishay Vishay Vishay Murata Murata Murata Murata Sullins Electronics Chicago Miniature Lamp Chicago Miniature Lamp
Table 5: AAT3783 Evaluation Board Bill of Materials.
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3783.2008.08.1.2
PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
Figure 5: AAT3783 Evaluation Board Top Layer.
Figure 6: AAT3783 Evaluation Board Middle Layer.
Figure 7: AAT3783 Evaluation Board Bottom Layer.
Figure 8: Magnified View of Exposed Paddles on AAT3783 Evaluation Board Top Layer.
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PRODUCT DATASHEET
AAT3783
BatteryManagerTM 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
Ordering Information
Package
TDFN34-16
Marking1
XQXYY
Part Number (Tape and Reel)2
AAT3783IRN-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/about/quality.aspx.
Package Information
TDFN34-16
3.000 0.050 0.700 0.050 1.600 0.050 R0.15 (REF) Pin 1 ID
Index Area
4.000 0.050
2.350 0.050
0.230 0.050
0.25 REF 1.600 0.050
0.430 0.050
Top View
Bottom View
0.750 0.050
0
+ 0.100 -0.000
0.230 0.050
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
(c) 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.
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0.450 0.050
0.35 REF
3783.2008.08.1.2

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