EUP8051A Low Cost 1A Linear Battery Charge Controllers DESCRIPTION FEATURES The EUP8051A is a single Lithium-Ion (Li-Ion) and Lithium–Polymer (Li-Pol) linear charge management controller for use in cost sensitive and portable applications. It combines high accuracy constant-current and constant-voltage regulation, cell preconditioning, temperature monitoring, automatic charge termination, charge-status indication, in a space-saving MSOP-8 package. The EUP8051A applies a constant current up to 1A to the battery and the charge current can be programmed externally with a sense-resistor. The EUP8051A automatically terminates the charge cycle when the charge current drops to the charge termination threshold (ITERM) after the charge-regulation voltage is reached. When the input supply is removed, the EUP8051A automatically enters a low-power sleep mode, dropping the battery drain current to less than 1µA. A battery charge state output pin is provided to indicate battery charge status through a display LED. The battery charge status output is a serial interface which may also be read by a system microcontroller. z z z Programmable Charge Current up to 1A 4.5V-7V Input Voltage Range Ideal for Single Cell (4.2V) Li-Ion or Li-Pol Batteries z z z z Preset Charge Voltage with ±1% Accuracy Constant-Current/Constant Voltage Operation Preconditioning of Low Voltage Cells Optional Cell-Temperature Monitoring Before and During Charge Charge Status Indication Automatic Battery Recharge Charge Termination by Minimum Current Automatic Low-Power Sleep Mode When Input Power is Removed Available in MSOP-8 Package RoHS Compliant and 100% Lead (Pb)-Free DS8051A Ver 1.1 Nov. 2006 1 z z z z z z APPLICATIONS z z Cellular Phones / PDAs/ MP3 Players/DSC Handheld Instruments EUP8051A Typical Application Circuit DS8051A Ver 1.1 Nov. 2006 2 EUP8051A Pin Configurations Part Number Pin Configurations EUP8051A MSOP-8 Pin Description PIN MSOP-8 I/O VCC 1 I Supply Voltage Input TS 2 I Temperature Sense Input STAT 3 O Charge Status Output VSS 4 CC 5 O FB/CE 6 I SNS 7 I Charge Control Output External Feedback input or Charge Enable Function. Input from controller or finely adjust the battery regulated voltage with external voltage divider Current Sense Input BAT 8 I Battery Voltage Input DS8051A Ver 1.1 Nov. 2006 DESCRIPTION Ground 3 EUP8051A Ordering Information Order Number Package Type Marking Operating Temperature range EUP8051A-42MIR1 MSOP-8 xxxx 8051A -20 °C to 70°C EUP8051A-□□ □ □ □ □ Lead Free Code 1: Lead Free 0: Lead Packing R: Tape& Reel Operating temperature range I: Industry Standard Package Type M: MSOP Output Voltage 42: 4.2V DS8051A Ver 1.1 Nov. 2006 4 EUP8051A Absolute Maximum Ratings Supply voltage, (Vcc with respect to GND) ------------------------------------------------------ -0.3 to +10V Input voltage, SNS, BAT, TS, PI (all with respect to GND)-------------------------- -0.3V to VCC +0.3V Sink current (STAT pin) not to exceed PD -------------------------------------------------------------- 20mA Source current (STAT pin) not to exceed PD ---------------------------------------------------------- 10mA Output current (CC pin) not to exceed PD -------------------------------------------------------------- 40mA Maximum Junction Temperature, TJ ------------------------------------------------------------------- 150°C Storage temperature range, Tstg ------------------------------------------------------------- -65°C to 150°C Lead temperature (soldering, 10s) -----------------------------------------------------------------300°C Package Thermal Resistance, θJA- MSOP8 ---------------------------------------------------------- 80°C/W Recommended Operating Conditions Min. Max. Unit Supply voltage, VCC 4.5 7 V Operating free-air temperature range, TA -20 70 °C Electrical Characteristics over Recommended Operating Free-Air Temperature Range EUP8051A Symbol Parameter Conditions Min. Typ. Max. I(VCC) VCC current I(VCCS) VCC Sleep current VCC=5V >VCC(min), Excluding external loads 0.5 Unit 1 mA V(BAT) ≥ V(min), V(BAT)-VCC ≥ 0.8V 6 µA IIB(BAT) Input bias current on BAT pin V(BAT)=V(REG) 1 µA IIB(SNS) Input bias current on SNS pin V(SNS)=5V 1 µA IIB(TS) Input bias current on TS pin V(TS)=5V 1 µA IIB(PI) Input bias current on PI pin V(PI)=5V 1 µA 4.242 V Battery Voltage Regulation VO(REG) Output voltage DS8051A Ver 1.1 Nov. 2006 EUP8051A-4.2 5 4.158 4.20 EUP8051A Electrical Characteristics Over Recommended Operating Free-Air Temperature Range Symbol V(SNS) Parameter Conditions Current regulation threshold Voltage at pin SNS, relative to VCC EUP8051A Unit Min. Typ. Max. 180 200 220 mV 5 15 25 mV 29 30 31 58 60 62 3.14 3.2 3.26 Charge Termination Detection I(TERM) Charge termination current Voltage at pin SNS, relative to VCC detect threshold 0°C ≤ TA ≤ 50°C Temperature Comparator V(TS1) Lower temperature threshold V(TS2) Upper temperature threshold TS pin voltage %VCC Precharge Comparator V(min) Precharge threshold EUP8051A-4.2 V Precharge Current Regulation I(PRECHG) Precharge current regulation Voltage at pin SNS, relative to VCC 0°C ≤ TA ≤ 50°C Voltage at pin SNS, relative to VCC 0°C ≤ TA ≤ 50°C , VCC=5V 18 5 mV 33 mV VRCH comparator(Battery Recharge Threshold) V(RCH) Recharge threshold EUP8051A-4.2 VOL(STAT) Output(low)voltage IOL=10mA VOH(STAT) Output(high)voltage IOH=5mA VOL(CC) Output low voltage IO(CC)=5mA(sink) IO(CC) Sink current VO(REG)- VO(REG)- VO(REG)102mV 100mV 98mV V STAT Pin 0.7 VCC-0.8 V CC Pin DS8051A Ver 1.1 Nov. 2006 Not to exceed power rating specification(PD) 6 5 2 V 40 mA EUP8051A Typical Operating Characteristics Battery Recharge Threshold vs. Temperature 4.30 4.35 4.25 Battery Recharge Threshold(V) Battery Voltage Regulation(V) Battery Voltage Regulation vs. Temperature 4.40 4.30 4.25 4.20 4.15 4.10 4.05 4.20 4.15 4.10 4.05 4.00 3.95 3.90 4.00 -20 0 20 40 60 -20 80 0 20 40 60 80 60 80 o o Temperature( C) Temperature( C) Precharge Threshold vs. Temperature Current Regulation vs. Temperature 3.40 1300 1200 3.30 Current Regulation(mA) Precharge Threshold(V) 3.35 3.25 3.20 3.15 3.10 1100 1000 900 3.05 3.00 -20 0 20 40 60 800 80 -20 0 o Temperature( C) 20 40 o Temperature( C) Precharge Threshold vs. Temperature Battery Voltage Regulation vs. Supply Voltage 4.40 4.35 Battery Voltage Regulation(V) Precharge Threshold(mA) 140 120 100 80 60 -20 0 20 40 60 4.20 4.15 4.10 4.05 4.5 Temperature( C) Nov. 2006 4.25 4.00 80 o DS8051A Ver 1.1 4.30 5.0 5.5 6.0 Supply Voltage(V) 7 6.5 7.0 EUP8051A Precharge Threshold vs. Supply Voltage Current Regulation vs. Supply Voltage 1300 140 Precharge Threshold(mA) Current Regulation (mA) 1200 1100 1000 900 120 100 80 60 800 4.5 5.0 5.5 6.0 4.5 6.5 Supply voltage(V) DS8051A Ver 1.1 Nov. 2006 5.0 5.5 Supply Voltage(V) 8 6.0 EUP8051A Application Information Functional Description The EUP8051A is an advanced 1A linear charge controller for single Li-Ion of Li-Pol applications. Refer to Blocking Diagram (Figure3) and Operation Flow Chart (Figure4) in this section. DS8051A Ver 1.1 Nov. 2006 9 EUP8051A Power On Reset VCC Applied NO Sleep Mode YES Temperature Fault NO Temperature Test TS>VTS1 TS<VTS2 YES Preconditioning Test VMIN > VBAT YES Low Current Conditioning Charge (Trickle Charge) NO Current Phase Test VREG>VBAT YES Constant Current Charging Mode NO Voltage Phase Test IBAT>ITERM YES Constant Voltage Charging Mode NO Charge Termination NO Recharge Test VRCH>VBAT YES Figure4. Operation Flow Chart DS8051A Ver 1.1 Nov. 2006 10 EUP8051A Qualification and Precharge When power is applied, the EUP8051A starts a charge-cycle if a battery is already present or when a battery is inserted. Charge qualification is based on battery temperature and voltage. The EUP8051A suspends charge if the battery temperature is outside the V(TS1) to V(TS2) range and suspends charge until the battery temperature is within the allowed range. The EUP8051A also checks the battery voltage. If the battery voltage is below the precharge threshold V(min), the EUP8051A uses precharge to condition the battery. The conditioning charge rate I(PRECHG) is set at approximately 10% of the regulation current. The conditioning current also minimizes heat dissipation in the external pass-element during the initial stage of charge. See Figure5 for a typical charge-profile. Voltage Regulation Phase The voltage regulation feedback is through the BAT pin. This input is tied directly to the positive side of the battery pack. The EUP8051A monitors the battery-pack voltage between the BAT and VSS pins. The EUP8051A is offered in two fixed-voltage versions:4.2V. FB/CE Pin Function This pin has two functions, one is to enable/disable the charge function, and the other is to finely adjust battery regulation voltage. Connect this pin to VDD to enable EUP8051A, and connect to ground to disable it (Figure7). If this pin is connected to a voltage divider as shown in Figure8, it can be a 2.15V reference voltage to adjust the output regulation voltage as desired. Current Regulation Phase The EUP8051A regulates current while the battery-pack voltage is less than the regulation voltage, VO(REG). The EUP8051A monitors charge current at the SNS input by the voltage drop across a sense-resistor, RSNS, in series with the battery pack. In current sensing configuration (Figure6), RSNS is between the VCC and SNS pins, charge-current feedback, applied through pin SNS, maintains a voltage of V(SNS) across the current sense resistor. The following formula calculates the value of the sense resistor: R SNS = V (SNS) I ---------------------------- (1) O(REG) Where IO(REG) is the desired charging current. Example: For 0.55A, RSNS: 0.22V/0.55A: 0.4Ω For 1.0A, RSNS: 0.22V/1.0A: 0.22Ω DS8051A Ver 1.1 Nov. 2006 11 EUP8051A For PTC Thermistors R R V = 2.15 × (1 + FB1 )V O(REG) R FB2 Charge Termination and Recharge The EUP8051A monitors the charging current during the voltage-regulation phase. The EUP8051A declares a done condition and terminates charge when the current drops to the charge termination threshold, I(TERM). A new charge cycle begins when the battery voltage falls below the V(RCH) threshold. Battery Temperature Monitoring The EUP8051A continuously monitors temperature by measuring the voltage between the TS and VSS pins. A negative-or a positive-temperature coefficient thermistor (NTC, PTC) and an external voltage divider typically develop this voltage (See Figure9). The EUP8051A compares this voltage against its internal V(TS1) and V(TS2) thresholds to determine if charging is allowed. (See Figure10). The temperature sensing circuit is immune to any fluctuation in VCC, since both the external voltage divider and the internal thresholds (V(TS1) and V(TS2)) are referenced to VCC. The resistor values of R(T1) and R(T2) are calculated by the following equations: For NTC Thermistors R T1 T2 = = 5× R 3 × (R TH TC ×R -R TC TH ) ----------------------- (3) 5× R ×R TH TC --------------- (4) [(2 × (R ) - (7 × R )] TH TC DS8051A Ver 1.1 Nov. 2006 T2 = 5× R 3 × (R TH TH 5× R ×R -R TC TC ) ---------------------- (5) ×R TH TC [(2 × (R ) - (7 × R )] TH TC ------------- (6) Where R(TC) is the cold temperature resistance and R(TH) is the hot temperature resistance of thermistor, as specified by the thermistor manufacturer. RT1 or RT2 can be omitted if only one temperature (hot or cold) setting is required. Applying a voltage between the V(TS1) and V(TS2) thresholds to pin TS disables the temperature-sensing feature. R R T1 = 12 EUP8051A Charge Inhibit Function The TS pin can be used as charge-inhibit input. The user can inhibit charge by connecting the TS pin to VCC or VSS (or any level outside the V(TS1) to V(TS2) thresholds). Applying a voltage between the V(TS1) and V(TS2) thresholds to pin TS returns the charger to normal operation. Charge Status Indication The EUP8051A reports the status of the charger on the 3-state STAT pin. The following table summarized the operation of the STAT pin. Condition Battery conditioning and charging Charge complete(done) Temperature fault or sleep mode STAT pin High Low Hi-Z The STAT pin can be used to drive a single LED (Figure1), dual-chip LEDs (Figure2) or for interface to a host or system processor (Figure11). When interfacing the EUP8051A to a processor, the user can use an output port, to recognize the high-Z state of the STAT pin. In this configuration, the user needs to read the input pin, toggle the output port and read the STAT pin again. In a high-Z condition, the input port always matches the signal level on the output port. Selecting Input Capacitor In most applications, all that is needed is high-frequency decoupling capacitor. A 0.1µF ceramic, placed in proximity to VCC and VSS pins, works well. The EUP8051A works with both regulated and unregulated external dc supplies. If a non-regulated supply is chosen, the supply unit should have enough capacitance to hold up the supply voltage to the minimum required input voltage at maximum load. If not, more capacitance must be added to the input of the charger. Selecting Output Capacitor The EUP8051A does not require any output capacitor for loop stability. In order to maintain good AC stability in the Constant Voltage mode, a minimum capacitance of 10µF is recommenced to bypass the VBAT pin to VSS. This capacitance provides compensation when there is no battery load. In addition, the battery and interconnections appear inductive at high frequencies. These elements are in the control feedback loop d＞uring Constant Voltage mode. Therefore, the bypass capacitance may be necessary to compensate for the inductive nature of the battery pack. Virtually any good quality output filter capacitor can be used, independent of the capacitor’s minimum ESR (Effective Series Resistance) value. The actual value of the capacitor and its associated ESR depends on the forward transconductance (gm) and capacitance of the external pass transistor. A 10µF tantalum or aluminum electrolytic capacitor at the output is usually sufficient to ensure stability for up to a 1A output current. Selecting An External Pass-Device (PMOS or PNP) The EUP8051A is designed to work with both P-channel MOSFET or PNP transistor. The device should be chosen to handle the required power dissipation, given the circuit parameters, PCB layout and heat sink configuration. The following examples illustrate the design process for PMOS device: Low-Power Sleep Mode When the input supply is disconnected, the charger automatically enters power-saving sleep mode. Only consuming an ultra-low 1µA in sleep mode, the EUP8051A minimizes battery drain when it is not charging. DS8051A Ver 1.1 Nov. 2006 13 P-Channel MOSFET Selection steps for a P-channel MOSFET: We will use the following conditions: VI=5V (with 10% supply tolerance); I(REG)=1A, 4.2-V single-cell Li-Ion. VI is the input voltage to the charger and I(REG) is the desired charge current. (See Figure2) EUP8051A 1. Determine the maximum power dissipation, PD , in the transistor. The worst case power dissipation happens when the cell voltage, V(constant), is at its lowest (typically 3.1V at the beginning of current regulation phase) and VI is at its maximum. Where VD is the forward voltage drop across the reverse-blocking diode (if one is used), and VCS is the voltage drop across the current sense resistor. Determine the package size needed in order to keep the junction temperature below the manufacturer’s recommended value, TJMAX. Calculate the total theta, θ(°C/W), needed. θ θ JA JA = = DS8051A Ver 1.1 (T -T ) max(J) A(max) P D (150 - 40) 1.8 Nov. 2006 3. 4. 5. PD=(VI(MAX)－VD－VCS－VBAT)×IREG --------- (7) PD=(5.5－0.4－0.2－3.1)×1A PD=1.8W 2. It is recommended to choose a package with a lower θJA than the number calculated above. --------------(8) θJA = 61°C/W Select a drain-source voltage, V(DS), rating greater than the maximum input voltage. A 12V device will be adequate in this example. Select a device that has at least 50% higher drain current (ID) rating than the desired charge current I(REG). Verify that the available drive is large enough to supply the desired charge current. V(GS)=(VD+V(CS)+VOL(CC))－VI(min) -------------- (9) V(GS)=(0.4+0.2+1) － 4.5 V(GS)=-2.9 Where V(GS) is the gate-to-source voltage, VD is the forward voltage drop across the reverse-blocking diode (if one is used), and VCS is the voltage drop across the current sense resistor, and VOL(CC) is the CC pin output low voltage specification for the EUP8051A. Select a MOSFET with gate threshold voltage, V(GSth), rating less than the calculated V(GS). Reverse Blocking Protection The optional reverse-blocking protection diode, depicted in Figure1&2 provides protection from a faulted or shorted input, or from a reversed-polarity input source. Without the protection diode, a faulted of shorted input would discharge the battery pack through the body diode of the external pass transistor. If a reverse-protection diode is incorporated in the design, it should be chosen to handle the fast charge current continuously at the maximum ambient temperature. In addition, the reverse-leakage current of the diode should be kept as small as possible. 14 EUP8051A Packaging Information 8-Pin MSOP NOTE 1. Package body sizes exclude mold flash and gate burrs 2. Dimension L is measured in gage plane 3. Tolerance 0.10mm unless otherwise specified 4. Controlling dimension is millimeter. Converted inch dimensions are not necessarily exact. SYMBOLS A A1 A2 b C D E E1 e L y θ DS8051A Ver 1.1 Nov. 2006 DIMENSIONS IN MILLIMETERS MIN. NOM. MAX. 0.81 0.95 1.10 0.05 0.09 0.15 0.76 0.86 0.97 0.28 0.30 0.38 0.13 0.15 0.23 2.90 3.00 3.10 4.70 4.90 5.10 2.90 3.00 3.10 -----0.65 ----0.40 0.53 0.66 ----------0.10 0 -----6 15 DIMENSIONS IN INCHES MIN. NOM. MAX. 0.032 0.0375 0.043 0.002 0.004 0.006 0.030 0.034 0.038 0.011 0.012 0.015 0.005 0.006 0.009 0.114 0.118 0.122 0.185 0.193 0.201 0.114 0.118 0.122 -----0.026 -----0.016 0.021 0.026 ----------0.004 0 -----6