LX2203A Li-Ion Battery Charger ® TM P RODUCTION D ATA S HEET KEY FEATURES DESCRIPTION Up to 1A Charge Current Low Drop Out Design Reverse Leakage Protection Linear Thermal Control Loop Pre-Charge Conditioning Programmable Termination Current Short Circuit Protected Small 3x3mm MLP Package The LX2203A charges the battery in two phases: constant current and constant voltage. A reduced current conditioning mode is provided for deeply discharged batteries. The LX2203A automatically restarts if the battery voltage falls below the top-off threshold. The LX2203A enters a low quiescent current sleep mode when power is removed. The LX2203A is backward compatible with the LX2203. The difference is the LX2203A can terminate charging while using CCP resistors ranging from 90k to 1.5M and the LX2203 from 90k to 400k. WWW . Microsemi .C OM The Microsemi LX2203A is a tiny linear battery charger for Lithium Ion or Lithium Polymer batteries. The LX2203A includes built in MOSFET, accurate current and voltage regulation, reverse blocking protection, over temperature control, and charge status indicator. The accurate programmable charge current and independent termination current programming make it easy to logically reprogram the charge current limit at any time. APPLICATIONS PDAs, MP3 Players Cell Phones Charging Cradles Digital Cameras IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com PRODUCT HIGHLIGHT AC/DC Adapter VIN BAT VIN BAT STAT LX2203A CMP EN GND CCP + _ CTP EN 0 1 MODE Sleep mode – charge disabled Charge enabled. ON/OFF PACKAGE ORDER INFO LD Plastic MLP 10-Pin LX2203A TA (°C) RoHS Compliant / Pb-free -40 to 85 LX2203AILD Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. LX2203AILD-TR) Copyright © 2004 Rev. 1.0a, 2005-10-21 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 1 LX2203A Li-Ion Battery Charger ® TM P RODUCTION D ATA S HEET ABSOLUTE MAXIMUM RATINGS PACKAGE PIN OUT Peak Package Solder Reflow Temp(40 seconds max. exposure) ......................................260°C (+0 -5) Note: Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground. Currents are positive into, negative out of specified terminal. VIN 1 10 BAT VIN 2 9 BAT STAT 3 8 CMP CTP 4 7 EN GND 5 6 CCP Connect Bottom to Power GND LD PACKAGE THERMAL DATA (Top View) WWW . Microsemi .C OM Supply Voltage (VIN)....................................................................................... -0.3V to 7V Input Signals (SHDN, EN,CMP) ...................................................................... -0.3V to 7V Battery Charging Current (IBAT)....................................................................................1.2A Operating Junction Temperature................................................................... -40C to 150°C Storage Temperature Range.........................................................................-65°C to 150°C RoHS / Pb-free 100% Matte Tin Lead Finish LD Plastic Micro Leadframe Package 10-Pin THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA 49°C/W Junction Temperature Calculation: TJ = TA + (PD x θJA). The θJA numbers are guidelines for the thermal performance of the device/pc-board system. All of the above assume no ambient airflow. FUNCTIONAL PIN DESCRIPTION Name Description BAT Charging Output - This pin is wired to the positive terminal of the battery. (The negative battery terminal is wired to GND.) CCP Charge Current Programming Pin - A resistor (Rccp) is connected between this pin and GND. See application section for programming information. CMP Compensation Pin – Apply a 0.01µF capacitor between CMP and VIN pins. CTP Charge Termination Programming Pin – A resistor (Rctp) is connected between this pin and GND See application section for programming information. EN Enable - Applying a TTL compatible Hi signal enables the charger, a Low signal disables the charger and puts it in sleep mode. GND Common Ground. STAT Status - This pin is a logic low level when the battery is being charged. Pin can sink up to 5mA. PACKAGE DATA VIN Voltage Input – Supply Voltage. Must be greater than VBAT to charge. Copyright © 2004 Rev. 1.0a, 2005-10-21 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 2 LX2203A Li-Ion Battery Charger ® TM P RODUCTION D ATA S HEET ELECTRICAL CHARACTERISTICS Parameter ` ` Test Conditions Input Voltage VVIN Quiescent Current IGND Min LX2203A Typ Max 4.35 5 mA 3 VEN = Lo 7 µA 1.25 V CCP Bias Voltage VCCP 1.25 V CONSTANT VOLTAGE MODE VBAT(MAX) 4.16 4.2 4.24 V VDRP /VBAT(MAX) 96 97 98 % Charge Termination Taper Current VBAT = VBAT(MAX) 42 51 60 mA Taper Current @ Low Charge Level VBAT = VBAT(MAX); RCCP = 1.2M 37 48 60 mA 0.9 1.0 1.1 A VDRP CONSTANT CURRENT MODE ICOND Conditioning Current Mode Threshold Voltage VBAT(COND) VBAT < VBAT(COND) 4% 5% 6% ICOND IBAT VBAT(COND) /VBAT(MAX) 60 63 66 % 4.5 LOGIC STAT Logic High Output VSTAT ISTAT = -100uA STAT Logic Low Output VSTAT ISTAT = 5mA Logic Hi EN Select Threshold V 0.5 V 2.0 VEN Logic Lo EN bias current IEN VEN = Hi 0.8 8 µA 150 °C 5 µA THERMAL SHUTDOWN TJ ELECTRICALS Maximum Junction Temperature PASS ELEMENT Reverse mode current ` V VCTP Conditioning Current ` 6 VEN = Hi BAT Constant Current ` Units CTP Bias Voltage Top Off Charge Droop Threshold ` 70°C except where otherwise MAIN CIRCUITRY BAT Output Voltage ` Symbol ≤ WWW . Microsemi .C OM Unless otherwise specified, the following specifications apply over the ambient temperature 0°C ≤ TA noted and the following test conditions: VVIN = 5V, VBAT =3.8V, RCCP = 90.9k, RCTP = 150k. -IBAT VVIN < VBAT UNDER VOLTAGE LOCKOUT Rising Threshold Voltage VUVLO+ 4.2 V Falling Threshold Voltage VUVLO- 3.9 V Copyright © 2004 Rev. 1.0a, 2005-10-21 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 3 LX2203A Li-Ion Battery Charger ® TM P RODUCTION D ATA S HEET CHARGING PROFILE CHARGE CURRENT PROGRAMMING Charge Current (mA) Charge Voltage And Current 1200 4.0 3.5 Voltage 3.0 Current 2.5 2.0 1.5 1000 800 600 400 200 1.0 0 0.5 0 4.0 8.0 0 12.0 16.0 WWW . Microsemi .C OM 4.5 Iccp Current (µA) 0 0.5 1.0 1.5 2.0 2.5 Constant Charge Current Programming Charge Time (hours) TERMINATION CURRENT PROGRAMMING CHARGE VOLTAGE DISTRIBUTION 300 250 200 600 COUT 400 150 100 200 50 0 0 20 40 60 80 100 0 4.171 4.174 4.176 4.179 4.181 4.183 4.186 4.188 4.191 4.193 4.196 4.198 4.201 4.203 4.206 4.208 4.210 4.213 4.215 4.218 4.220 4.223 4.225 4.228 4.230 Termination Current (mA) 800 1/Rctp (micromhos) Termination Current Programming V Post Trim Bat Volt 1.0A CHARGE CURRENT DISTRIBUTION 50MA TERMINATION DISTRIBUTION 70 1400 60 1200 50 Count Count 1000 40 30 800 600 CHARTS 20 400 10 200 More -20 -24 -28 -32 -36 -40 -44 -48 -52 -56 0 -60 -920.000E-03 -926.939E-03 -933.878E-03 -940.816E-03 -947.755E-03 -954.694E-03 -961.633E-03 -968.571E-03 -975.510E-03 -982.449E-03 -989.388E-03 -1.003 -996.327E-03 -1.010 -1.017 -1.024 -1.031 -1.038 -1.045 -1.052 -1.059 -1.066 -1.073 -1.080 -1.087 0 A Charge Current Post Trim Copyright © 2004 Rev. 1.0a, 2005-10-21 mA Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 4 LX2203A Li-Ion Battery Charger ® TM P RODUCTION D ATA S HEET SIMPLIFIED BLOCK DIAGRAM WWW . Microsemi .C OM + EN ENABLE UVLO CHARGE CONTROL VDD STAT BAT CHARGE TERMINATION CONTROL CTP CONSTANT VOLTAGE CONTROL CMP TEMPERATURE CONTROL CONDITIONING THRESHOLD CONSTANT CURRENT CONTROL CCP CONDITION CURRENT BLOCK DIAGRAM GND LX2203A Figure 1 – Simplified Block Diagram Copyright © 2004 Rev. 1.0a, 2005-10-21 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 5 LX2203A ® TM Li-Ion Battery Charger P RODUCTION D ATA S HEET THEORY OF OPERATION WWW . Microsemi .C OM LX2203 CONTROL FLOW DIAGRAM Return to START if EN changes state or VIN is removed. START EN = 1 NO SLEEP YES V IN > V UVLO NO YES V IN > V BAT NO CONSTANT VOLTAGE CHARGE MODE YES NO V BAT >60% CONDITION CHARGE MODE TEMP < 150 NO REDUCE CHARGE CURRENT YES YES CONSTANT CURRENT CHARGE MODE NO I BAT <IMIN YES TEMP < 150 NO REDUCE CHARGE CURRENT APPLICATIONS VOLTAGE MONITORING MODE (STATE). YES NO V BAT <97% V BAT > V CV NO YES YES RETURN TO THE TOP OF THE CHART. Figure 2 – Control Flow Diagram Copyright © 2004 Rev. 1.0a, 2005-10-21 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 6 LX2203A Li-Ion Battery Charger ® TM P RODUCTION D ATA S HEET TYPICAL APPLICATIONS VIN BAT VIN BAT STAT LX2203A CMP EN GND CCP + _ CTP WWW . Microsemi .C OM AC/DC Adapter ON/OFF Figure 3 –Basic charger from Wall Adapter with 1A constant current and 50mA termination current Input Power VIN BAT VIN BAT + EN GND CCP _ 0.01µF 243K CTP 165K 2.7K 150K STAT LX2203A CMP 1.21M BSS138DW-7 ON/OFF APPLICATIONS CP1 CP2 IBAT 100mA 500mA 1.0A CP1 L L H CP2 L H H Figure 4 – Wall adapter and USB Charger (1A, 500mA, 100mA, selectable) Copyright © 2004 Rev. 1.0a, 2005-10-21 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 7 LX2203A TM Li-Ion Battery Charger ® P RODUCTION D ATA S HEET APPLICATION NOTE PROTECTION FEATURES Conditioning Current Mode – If the battery terminal voltage is less than 2.65V, the battery charger will reduce the charge current to 5%. This also protects the appliance from overheating by trying to drive the full charging current into a damaged battery. Under Voltage Lockout – The charge cycle will not start until the VIN voltage rises above 4.2V. Hysteresis prevents chattering on and off. Thermal Control loop – If the power dissipation of the charger becomes excessive, the charge current will be reduced to prevent the die temperature from getting above 150°C. This does not cause the charge cycle to stop. Reverse current blocking – If VIN is grounded, current will not flow from the battery through the charger. No external blocking diode is required on the input. Sleep Mode – If the EN pin is logic low or if VIN is removed, the charger enters a sleep mode where a very low quiescent current prevents drain from the battery. TERMINATION CURRENT PROGRAMMING The charge termination current (or minimum taper current) is set by selecting a value for the CTP resistor using the following formula: R CTP = 7500 I TERM For example, for a termination current of 50mA set RCTP = 150k. This formula applies to termination currents ranging from 20mA to 500mA. It is possible to change the termination current to different levels for different charge rates. For a “quick charge”, the termination current can be set to about 50% of the constant current level; this charges the battery to about 75% capacity. For a full charge (taking several hours) the termination current can be set to 5% of the constant current level. The circuit below allows switching between the two levels: CTP 16.5k 150k Quick/Slow Figure 5 – 500mA or 50mA termination current Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 8 APPLICATIONS CONSTANT CHARGE CURRENT PROGRAMMING The charge current during the constant current charge mode is programmable by controlling the current flowing LAYOUT GUIDELINES from the CCP pin. A graph showing this relationship is • It is important when laying out the LX2203A to place included in this specification. The CCP pin is regulated to 10µF ceramic capacitors close to the VIN and VBAT IC 1.25V when the charger is active. Connecting a resistor from terminals to filter switching transients. the CTP to ground will produce a CTP current of: • It is important to provide a low thermal impedance 1.25 path from the thermal pad on the bottom of the LX2203A I CTP = package to the ground plane of the circuit board to maximize R CCP the heat dissipation. To minimize charge time it is best not to (Continued on next page) rely on the thermal control feature as this feature will extend the charging time when activated. Copyright © 2004 Rev. 1.0a, 2005-10-21 WWW . Microsemi .C OM GENERAL DESCRIPTION The LX2203A is designed to charge a single cell Lithium Ion (Li-ion) battery using two modes: a constant current mode, where the charge current is held constant and the battery terminal voltage rises to 4.2V; this is followed by constant voltage mode, where the battery voltage is held at 4.2V and the charge current starts to taper off. Once the taper current reaches the charge termination current level the charge cycle is ended and the STAT indicator turns off. If the fully charged battery terminal voltage drops to 4.07V, the battery charge cycle will be restarted. LX2203A Li-Ion Battery Charger ® TM P RODUCTION D ATA S HEET APPLICATION NOTE (CONTINUED) CCP Vcc R1 1.21M 500mA/100mA R2 Charge Current ICCP Current RCCP Value 1.0A 13.75µA 90.9K 500mA 6.22µA 200K 100mA 1.00µA 1200K CCP Rsw 243k It is possible to change the constant current setting by changing the RCCP resistor while in charge mode. Since the termination current is independent of the charge current, lowering the constant charge current will increase the charge time, but will not reduce the stored charge in the battery at the charge termination point. The circuit in Figure 4 is an example of a battery charger configured to charge at 1A, 500mA or 100mA. The switches are logically controlled and reduce the resistance at the CCP pin when switched in. It is possible to eliminate the MOSFET devices if open drain logic is available. The logic for the CP1 and CP2 would normally come from the appliance processor which would need to have the capability to communicate over the USB interface. If there is only one power connector and the USB interface is active, the logic could assume the power was coming from the USB bus and not the wall adapter. If the USB interface is active, the USB application will know if the appliance has been enumerated as a high or low load and would set CP1 and CP2 appropriately. It is possible to change the current programming circuit to drive it directly with CMOS logic, but this requires that the CMOS logic power supply be well regulated (±2%). Each switch resistor leg in Figure 4 can be replaced with a two resistor network tied to the output of a CMOS gate. WWW . Microsemi .C OM CONSTANT CHARGE CURRENT PROGRAMMING (CONTINUED) The table below lists some popular Constant Current Settings along with the associated CCP pin current and programming resistor: 1.21M 500mA/100mA Figure 6 – Circuits to provide 100mA and 500mA constant charge currents. The values of R1 and R2 are selected such that: VCC × R2 R1 × R 2 = R SW = 1.25 & R1 + R 2 R1 + R 2 Solving these equations: R1 = VCC × R SW R × R SW & R2 = 1 1.25 R 1 − R SW For VCC = 3.3V and RSW = 243k; R1 = 649k; R2 = 392k. These values should provide charge currents of 100mA and 500mA. COMPENSATION CAPACITOR A compensation capacitor of value 0.01µF is required between the CMP pin and VIN. APPLICATIONS Copyright © 2004 Rev. 1.0a, 2005-10-21 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 9 LX2203A Li-Ion Battery Charger ® TM P RODUCTION D ATA S HEET PACKAGE DIMENSIONS WWW . Microsemi .C OM LD 10-Pin Plastic MLP Dual Exposed Pad D e L E E2 Top View Bottom View b D2 A A3 A1 MILLIMETERS MIN MAX 0.80 1.00 0 0.05 0.20 REF 0.18 0.30 3.00 BSC 2.23 2.48 0.50 BSC 3.00 BSC 1.49 1.74 0.30 0.50 INCHES MIN MAX 0.0315 0.0394 0 0.0019 0.0079 REF 0.0071 0.0118 0.1181 BSC 0.0878 0.0976 0.0197 BSC 0.1181 BSC 0.0587 0.0685 0.0071 0.0197 Note: 1. Dimensions do not include mold flash or protrusions; these shall not exceed 0.155mm(.006”) on any side. Lead dimension shall not include solder coverage. Copyright © 2004 Rev. 1.0a, 2005-10-21 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 10 MECHANICALS Dim A A1 A3 b D D2 e E E2 L LX2203A TM Li-Ion Battery Charger ® P RODUCTION D ATA S HEET NOTES WWW . Microsemi .C OM NOTES PRODUCTION DATA – Information contained in this document is proprietary to Microsemi and is current as of publication date. This document may not be modified in any way without the express written consent of Microsemi. Product processing does not necessarily include testing of all parameters. Microsemi reserves the right to change the configuration and performance of the product and to discontinue product at any time. Copyright © 2004 Rev. 1.0a, 2005-10-21 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 11