LX2207 ® TM Three Level Lithium Ion Battery Charger P RODUCTION D ATA S HEET KEY FEATURES DESCRIPTION charge in progress, battery fully charged and external power on. The STAT pin is capable of sourcing or sinking 10mA. The DCOK output is an open drain output and can sink 20mA. The LX2207 enters a low quiescent current sleep mode when power is removed or when it is logically shutdown to minimize battery drain. There are several protection features which include: under voltage lock out, reverse current blocking on the IN pin, a thermal loop to reduce charge current to maintain a low die temperature, an unsafe battery temperature charge inhibitor, and conditioning mode is provided for deeply discharged batteries. Three charge levels for adapter, and USB Hi and Low 0.5% Float voltage tolerance Charging up to 1A. Charging from USB port. USB current compliance Full battery Indicator CC/CV w thermal Feedback Battery temp monitor Precision charge termination Power Good Indication WWW . Microsemi .C OM The LX2207 can use a wall adapter or USB power source to charge a single cell Lithium Ion or Lithium Polymer battery. There are three logic selectable and programmable charge current levels: the high charge programming level is typically set for charging from the adapter, the low level charge programming level is typically set to 500mA for USB full USB charging and 100mA (20%) for reduced level USB charging. In addition to setting the high-level charge current, the HCP programming resistor also sets the termination current at 10% of the constant current level and the conditioning current at 5% of the constant current level. Power status indicators (STAT and DCOK) can be configured to show APPLICATIONS MP3 player PDA PMC Digital Camera Charge Cradle IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com PRODUCT HIGHLIGHT LX2207 PACKAGE ORDER INFO TA (°C) LD Plastic MLPD 12-Pin RoHS Compliant / Pb-free -40 to 85 LX2207ILD Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. LX2207ILD-TR) Copyright © 2005 Rev. 1.0, 2007-01-03 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 1 LX2207 ® TM Three Level Lithium Ion Battery Charger P RODUCTION D ATA S HEET ABSOLUTE MAXIMUM RATINGS PACKAGE PIN OUT 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. IN 1 12 BAT CMP 2 11 TMP STAT 3 10 HCP DCOK 4 9 LCP SD 5 8 H/L 20% 6 7 GND LD Package THERMAL DATA LD (Top View) RoHS / Pb-free 100% matte Tin Lead Finish Plastic Micro Leadframe Package 12-Pin THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA WWW . Microsemi .C OM Supply Input Voltage (IN, BAT) ...................................................................... -0.3V to 7V All other pins ............................................................................................-0.3V to VSUPPLY Battery Charging Current .............................................................................................1.1A Operating Temperature Range .........................................................................-40 to 150°C Maximum Operating Junction Temperature .............................................................. 150°C Storage Temperature Range.........................................................................-65°C to 150°C Peak Temp. for Solder Reflow (40 seconds maximum exposure).................. 260°C (+0 -5) 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 Pin # BAT 12 Battery – Connect to a single cell Lithium Ion Battery. CMP 2 Compensation – Connect a series combination of a 1k resistor and a 0.47µF capacitor from CMP to IN. DCOK 4 Power status logic pin and LED driver – This pin is an open drain output that can sink 20mA of current to drive an external LED. This pin is low impedance to GND when the Input voltage is high enough to charge the Battery. GND 7 Ground – Connect to the system ground. HCP 10 High Current Programming (and Termination Current Programming) – Connect a resistor to ground to set the constant current high level. The termination current is set to 1/10 of the High Current Programming Level. For a value of 19.6k, the High Current is 460mA and the Termination Current is 46mA. H/ L 8 High or Low load select logic input – A logic high selects the constant charge current level set by the HCP pin resistor and a logic low selects the constant charge current level set by the LCP pin resistor IN 1 Input Power – Connect to a wall adapter or a USB power plug. LCP 9 Low Current Programming – Connect a resistor to ground to set the constant current low level. For a value of 19.6k, the High Current is 460mA and the 20% current is 92mA. SD 5 Shutdown – A logic high places the LX2207 in sleep mode; can also be used for USB suspend. STAT 3 Charging status logic pin and LED driver – This pin can source or sink 10mA of current to drive an external LED in either output state. This pin is low (current sinking mode) when the battery is in charging mode and becomes high (current sourcing mode) when the charge cycle is finished. It becomes high impedance when the input power is removed. TMP 11 Battery Temperature Monitor – This sense pin determines the battery temperature for charging out of temperature range lockout and is connected to a resistor network as defined in the Applications section. The TMP pin is grounded if this function is not used. 20% 6 20% select logic input – When the low current level is selected by the H/L pin, a logic high on 20% selects the constant charge current level set by the LCP pin resistor and a logic low selects 20% of this value. Copyright © 2005 Rev. 1.0, 2007-01-03 Description Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 2 PACKAGE DATA Name LX2207 ® TM Three Level Lithium Ion Battery Charger P RODUCTION D ATA S HEET ELECTRICAL CHARACTERISTICS ` INPUT CIRCUITRY Input Voltage Battery Voltage Under Voltage Charging Lockout UVLO Hysteresis Input Supply Current ` VIN VBAT VIN UVLO IIN BATTERY CHARGER Constant Voltage Charging Constant Voltage Charging HCP Bias Voltage LCP Bias Voltage Max Battery Charge Current VBAT VBAT VHCP VLCP IBAT Conditioning Current Conditioning Current Conditioning Current Threshold Charge Termination Current Charge Termination Current Charge Termination Current IBAT ICOND VBAT IBAT IBAT IBAT Top Off Charge Droop Threshold VBAT Battery Drain Current IBAT 4.35 Rising input VBAT = 3.2V 3.5 VBAT = 4.2V; battery charged SHDN = High IBAT < 100mA IBAT < 100mA @ 25C IBAT > 100mA 4.16 4.18 HCP=12.1k H/L = Low H/L = Low, 20% = Low VBAT < VCCT VBAT < VCCT; HCP = 110k Rising Battery Voltage HCP = 19.6k HCP = 110k HCP = 210k 665 430 84 13 2.6 2.5 34 96 VBAT = 4.2V; battery charged VBAT > VIN SD = High (Shutdown Mode) 3.8 300 1 35 6 4.3 4 V V V mV mA µA 2 50 4.2 4.2 1.25 1.25 710 460 92 23 4.6 2.7 46 9 5 4.24 4.22 V V V V mA mA mA mA mA V mA mA mA 97 98 1 5 1 30 30 5 µA µA µA 4.5 5 0.5 V V 772 495 97 33 7.8 2.9 59 % VBAT WWW . Microsemi .C OM The following specifications apply over the operating ambient temperature -40°C ≤ TA ≤ 85°C except where otherwise noted and the following test conditions:. IN = 5.0V; SD = Low; H/L = High, 20% = High; BAT = 3.6V; HCP =12.1k, LCP=19.6k; TMP = 0V. LX2207 Parameter Symbol Test Conditions Units Min Typ Max VCVL ` LOGIC STAT Logic High Output STAT Logic Low Output VSTAT VSTAT Input Logic : SD, H/L, 20% VLOG(IN) Input Current : SD, H/L ILOG(IN) Input Current : 20% I20%(IN) VLOG(OUT) Output Logic : DCOK VIN = 5.0V, IDRV = -10mA VIN = 5.0V, IDRV = 10mA Logic Hi, Logic Lo Logic Hi, VLOG = 2V Logic Lo, VLOG = 0V Logic Hi, VLOG = 2V Logic Lo, VLOG = 0V Logic Hi, ILOG = 10k pullup to 3.3V Logic Lo, ILOG = 20mA 4.2 1.2 0 -2 -2 -2 3.1 2 0 -0.8 -0.8 0.4 4 2 2 2 0.5 V µA uA V ` BATTERY TEMPERATURE MONITOR VCOLD Hot Temp Fault Threshold VHOT TFB Disable Voltage Temp Loop Regulation VDIS Copyright © 2005 Rev. 1.0, 2007-01-03 Rising Threshold Falling Threshold Falling Threshold Rising Threshold 75 130 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 0.75 x VIN 0.72 x VIN 0.28 x VIN 0.30 x VIN 100 140 150 150 V V V V mV °C ELECTRICALS Cold Temp Fault Threshold Page 3 LX2207 Three Level Lithium Ion Battery Charger ® TM P RODUCTION D ATA S HEET SIMPLIFIED BLOCK DIAGRAM WWW . Microsemi .C OM + SD ENABLE DCOK UVLO STAT TMP CHARGE CONTROL BAT IN CHARGE TERMINATION CONTROL CONSTANT VOLTAGE CONTROL TEMPERATURE CONTROL CONDITIONING THRESHOLD H/L COND. CURRENT 20% LCP BLOCK DIAGRAM HCP LOW CHARGING CURRENT HIGH CHARGING CURRENT GND Copyright © 2005 Rev. 1.0, 2007-01-03 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 4 LX2207 ® TM Three Level Lithium Ion Battery Charger P RODUCTION D ATA S HEET CONTROL LOGIC DIAGRAM WWW . Microsemi .C OM RETURN TO START IF VIN > VBAT, UVLO, SD, CHANGE STATE. START YES SD NO VIN > VBAT NO SLEEP YES YES UVLO NO VOLTAGE MONITORING MODE (STATE). VBAT<97% NO YES VBAT>60% NO CONDITION CHARGE MODE CONSTANT VOLTAGE CHARGE MODE YES CONSTANT CURRENT CHARGE MODE IMAX DETERMINED BY THE STATE OF H/L, RHCP, RLCP and 20%. TEMP < 140 NO REDUCE CHARGE CURRENT YES TEMP < 140 NO YES ICC < IMAX NO REDUCE CHARGE CURRENT ICC< IMAX NO REDUCE CHARGE CURRENT YES REDUCE CHARGE CURRENT NO ITAPER DETERMINED BY RHCP. APPLICATIONS IBAT<ITAPER YES YES NO VBAT> VCV RETURN TO THE TOP OF THE CHART. YES Copyright © 2005 Rev. 1.0, 2007-01-03 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 5 LX2207 Three Level Lithium Ion Battery Charger ® TM P RODUCTION D ATA S HEET APPLICATION CIRCUITS Adapter or USB Power Pin 1k 0.47u H/L Shutdown SD USB Hi/Low 20% Control Logic HCP LX2207 LCP 12.1k 2.49k Full CMP 10k Grounded Pin in USB cable. Leave open in Adapter Cable. STAT IN Charging 19.6k DCOK 2.49k Power On 121k TMP BAT GND Battery Current Programming WWW . Microsemi .C OM Status 2.49k 24.9k Battery Temperature Lockout Sensing Figure 1 – Typical Application – 750mA adapter charge current and 500mA or 100mA maximum USB charge currents. A grounded spare pin in the USB power cable can be used to sense when the 500mA USB current power source is being used. This application also uses three LED indicators for Power attached, Battery Charging and Battery full. This configuration also implements circuitry to lockout battery charging if the battery is less than 0C or greater than 60C. APPLICATIONS Copyright © 2005 Rev. 1.0, 2007-01-03 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 6 LX2207 ® TM Three Level Lithium Ion Battery Charger P RODUCTION D ATA S HEET THEORY OF OPERATION GENERAL DESCRIPTION CONDITIONING CURRENT CHARGE MODE A conditioning current is applied to batteries that are deeply discharged and have a terminal voltage less than 60% of the constant voltage level. The conditioning current is 5% of the HCP programmable constant current level. Once the battery terminal voltage exceeds the conditioning current threshold, the full constant current level is applied (unless one of the other charger control loops limits charging current). CHARGE TERMINATION MODE To increase system battery life and avoid float charging, the LX2207 turns off the pass element once the battery is fully charged. The charge termination state occurs at the end of constant voltage mode. The value of the resistor connected to the HCP programming pin sets the termination current. The STAT pin changes state when charge cycle has completed. TOP OFF CHARGE MODE Once the charger has completed a charge cycle, if power remains applied, the LX2207 enters a Voltage Monitoring mode. In this mode the LX2207 monitors the battery terminal voltage and applies a top off charge if the battery voltage drops below the top of threshold. USB CHARGE MODE AND CURRENT LIMIT The LX2207 is fully compliant with, and supports, the USB specifications – the Low Power Peripheral (100mA) and High Power Peripherals (500mA). USB current levels can be set using the appropriate values for the LCP programming resistor. 20% logic input selects USB high/low charge currents. When the SD pin is pulled high, the USB input enters Suspend mode and will not present a load to the IN pin. DCOK The IN input is monitored and DCOK is set to a logic low to report the presence of the power source with sufficient voltage to charge the battery. The DCOK threshold is the larger of the UVLO threshold or the battery voltage. WWW . Microsemi .C OM The LX2207 charges a single cell Lithium Ion battery using two steps: a constant current mode followed by a constant voltage mode. The maximum charging current during the Constant Current Mode of the charging profile can be logically set (using H/L) to two preprogrammed levels set by resistors connected to HCP and LCP (High and Low current). A 20% logic input selects either the full current set by the LCP resistor or 20% of that value. The charger will terminate constant voltage charging once the current drops below the taper current setting, which is 10% of the high charge current setting (determined by HCP resistor value). PROTECTION FEATURES Conditioning Current Mode – If the battery terminal voltage is less than 2.7V, 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 short circuited battery. Under Voltage Lockout – The charge cycle will not start until the IN voltage rises above 3.8V. Hysteresis helps alleviate 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 140°C. This does not cause the charge cycle to stop. Reverse current blocking – If IN input is grounded, current will not flow from the BAT pin through the charger. No external blocking diode is required on the input. Sleep Mode – If the SD pin is a logic high, the charger enters a sleep mode where a very low quiescent current prevents drain from the battery. ADAPTER OR USB SELECTION Copyright © 2005 Rev. 1.0, 2007-01-03 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 APPLICATIONS The LX2207 supports battery charging from a system that provides adapter power or USB power using the same external connector. Figure 1 shows one example of a system using a special USB adapter cable to determine whether the power source is USB or Wall Adapter. Similarly, if the system processor senses the absence of USB data, it can logically set the H/L logic level high for the wall adapter. Page 7 LX2207 ® TM Three Level Lithium Ion Battery Charger P RODUCTION D ATA S HEET APPLICATION NOTE Using the table below it can be seen that for a programming current value of 11.4µA, the corresponding maximum charge current is 92mA. The termination current determines the point at which the charge cycle is terminated and the battery is determined to be fully charged. The termination current is determined by the value of the HCP programming current as determined by the HCP programming resistor. For a value of IHCP = 11.4µA (as was used in the previous example), the termination current from the chart below can be seen to be 9mA. Term ination Current vs IHCP 120 CURRENT PROGRAMMING RESISTORS 1.25 1.25 = = 11.4µA RHCP 110k 100 80 60 40 20 0 0.00 50.00 100.00 150.00 IHCP (in uA) The termination current is always roughly 10% of the maximum charge current set by the HCP resistor. INDEPENDENT TERMINATION CURRENT PROGRAMMING Charge Current vs IHCP (or ILCP) 1000 800 600 400 200 0 0.00 50.00 100.00 150.00 IHCP (in uA) Copyright © 2005 Rev. 1.0, 2007-01-03 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 8 APPLICATIONS For applications where a termination current other than 10% is required, the termination current can be set using the HCP resistor and the charge current can be set using the LCP resistor. In this case, the H/L pin is held low so that the HCP charge mode is never utilized. In this way the HCP pin only programs the termination current and conditioning current. 1200 Charge Current (in mA) Termination Current (in mA) The LX2207 has two programming resistors to control the battery charging current during the constant current charging mode of the battery charging cycle. When the H/L pin is high (selecting the High Current charging mode), the charge current is determined by the value of the HCP programming resistor. The maximum charge current is determined by the programming current at either the HCP or LCP programming pins (depending on the state of H/L); the range of each of these channels is identical. The programming current is the HCP or LCP pin voltage (typically 1.25V) divided by the value of the programming resistor. For example, the HCP current with a 110k resistor to GND is: IHCP = WWW . Microsemi .C OM LAYOUT In the layout of the Printed Circuit Board (PCB) it is important to provide a solid path from the IC power and ground pins to the power and ground planes of the PCB to provide a good conduction path for heat. This insures the LX2207 stays cool and can provide the maximum charge current to minimize the time required to charge the battery. For stability, and to reduce turn on – turn off transients, it is important to place capacitors close to the IN and BAT pins. Use a 10uF capacitor (X5R or X7R dielectric) for this purpose. The CMP pin resistor and capacitor should be located close to the CMP pin. The CMP pin is located next to the IN pin to facilitate this. The 1K resistor is not required for stability, but reduces the inrush current into the CMP pin when the IN voltage transient is applied. LX2207 ® TM Three Level Lithium Ion Battery Charger P RODUCTION D ATA S HEET APPLICATION NOTE To finish the design it is necessary to create the Thevenin Voltage and resistance using a voltage divider from the input pin (IN). WWW . Microsemi .C OM BATTERY TEMPERATURE MONITOR The LX2207 has an input to monitor the battery temperature during battery charging; this method assumes the battery pack contains a thermistor expressly for this purpose. A typical Lithium ion battery should only be charged from a range of 0°C to 60°C. For this calculation, a Vishay NTHS0402N01N1003J Thermistor was used. This thermistor is 327kΩ at 0°C, 100kΩ at 25°C and 24.9kΩ at 60°C. The thermistor must be biased with a Thevenin voltage source and series resistance to achieve the proper thresholds. A fixed value resistor is added in series with the thermistor to prevent it from becoming too low an impedance at high temperatures and causing the TMP input to default to off. VIN R1 TMP RMIN R2 RNTC VTH The values of R1 and R2 can be calculated as: RTH R1 = TMP R TH = 122k K RMIN R2 = RNTC Using a value of RMIN that is equal to the thermistor temperature at 60°C works well; therefore, for this example, set the value of RMIN to 24.9k. This has the effect of adding 24.9k to the thermistor resistance values so it becomes 352kΩ at 0°C, 125kΩ at 25°C and 49.8kΩ at 60°C. R1 × R TH = 14,800k R1 − R TH In this case, it is not necessary to use R2, because the value is so large it is insignificant. In this case, R1 = RTH. The final circuit for this example is: VIN 121k The equations for RTH and VTH are: TMP 0.29 × 0.74 × (R T = 0C − R T = 60C ) VTH = VIN (0.29 × R T = 0C ) − (0.74 × R T = 60C ) 24.9k = K = 0.99 RNTC The TMP voltages with this circuit are: Where R at temperature is the sum of the thermistor plus RMIN. Copyright © 2005 Rev. 1.0, 2007-01-03 APPLICATIONS ⎞ ⎛ K R TH = ⎜ − 1⎟ × R T = 0C = 121k ⎝ 0.74 ⎠ TEMP (°C) -20 0 25 60 80 RNTC 971k 327k 100k 24.9k 12.6k Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 VTMP (%VIN) 89% 74% 51% 29% 24% Page 9 LX2207 ® TM Three Level Lithium Ion Battery Charger P RODUCTION D ATA S HEET APPLICATION NOTE POWER STATUS INDICATORS Conditions STAT Charge in process Low Charge completed High CHARGING PROFILE CONDITIONING CURRENT Battery Charging USB High Level Conditioning Current vs IHCP 0.50 4.25 60 0.40 4.15 0.30 Ibat 4.10 0.25 4.05 0.20 0.15 4.00 0.10 3.95 B attery C u u ren t 0.35 Vbat Conditioning Current (in mA) 0.45 4.20 B attery V o ltag e WWW . Microsemi .C OM The STAT pin is designed to source or sink current. LEDs can be configured to indicate charging or battery full. The battery full indicator can be connected to DCOK rather than GND to insure it is off when the input power is removed and the STAT pin and DCOK pin go to a high impedance state. 0.05 3.90 0.00 0.0 60.0 120.0 50 40 30 20 10 0 0.00 50.00 100.00 150.00 IHCP (in uA) Time in minutes CHARTS Copyright © 2005 Rev. 1.0, 2007-01-03 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 10 LX2207 ® TM Three Level Lithium Ion Battery Charger P RODUCTION D ATA S HEET CONSTANT CURRENT (USB LOW) 20% CHARGE RATIO ADAPTER CHARGE CURRENT CONDITIONING CURRENT TERMINATION CURRENT WWW . Microsemi .C OM CONSTANT VOLTAGE CHART S Copyright © 2005 Rev. 1.0, 2007-01-03 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 11 LX2207 TM ® P RODUCTION D ATA S HEET COLD TMP THRESHOLDS (VIN = 5V) Rising voltage: HOT TMP THRESHOLDS (VIN = 5V) Rising voltage: WWW . Microsemi .C OM Falling Voltage: Three Level Lithium Ion Battery Charger Falling Voltage: CHARTS Copyright © 2005 Rev. 1.0, 2007-01-03 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 12 LX2207 Three Level Lithium Ion Battery Charger ® TM P RODUCTION D ATA S HEET PACKAGE DIMENSIONS LD 12-Pin Plastic MLP Dual Exposed Pad WWW . Microsemi .C OM D D2 L K E E2 Pin 1 ID MILLIMETERS MIN MAX 0.80 1.00 0.00 0.05 0.20 REF 3.00 BSC 3.00 BSC 1.87 2.12 1.06 1.31 0.45 BSC 0.20 MIN 0.30 0.50 INCHES MIN MAX 0.031 0.039 0.000 0.002 0.008 REF 0.118 BSC 0.118 BSC 0.074 0.083 0.042 0.052 0.018 BSC 0.008 MIN 0.012 0.020 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 © 2005 Rev. 1.0, 2007-01-03 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 13 MECHANICALS Dim A A1 A3 D E D2 E2 e K L A3 A1 A e LX2207 TM ® Three Level Lithium Ion Battery Charger P RODUCTION D ATA S HEET NOTES WWW . Microsemi .C OM NOTES Copyright © 2005 Rev. 1.0, 2007-01-03 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 14