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    TEL 13509685286 Q 1839845898 尚亿微电子 李华 1A Lithium Ion Battery Linear harger SX5058 SX5058 General Description Features SX5058 is a complete constant-current/constant voltage linear charger for single cell lithium-ion batteries. With a thermally enhanced 8-PIN SOP package on the bottom and low external component count make the SX5058 ideally suited for portable applications. Furthermore the SX5058 is specifically designed to work within USB power specifications. No external sense resistor is needed and no blocking diode is required due to the internal PMOSFET architecture .Thermal feedback regulates the charge current to limit the die temperature during high power operation or high ambient temperature .The charge voltage is fixed at 4.2V,and the charge current can be programmed externally with a single resistor. The SX5058 automatically terminates the charge cycle when the charge current drops to 1/10th the programmed value after the final float voltage is reached. When the input supply (wall adapter or USB supply) is removed the SX5058 automatically enters a low current state dropping the battery drain current to less than 2μA.The SX5058 can be put into shutdown mode reducing the supply current to 55μA. Other features include Battery temperature monitor, under-voltage lockout, automatic recharge and two status pins to indicate charge and charge termination. ●Protection of battery cell reverse connection ● Programmable charge current up to 1A ●No MOSFET sense resistor or blocking diode required ●Complete linear Charger in SOP8 Package for single Cell Lithium-Ion Batteries. ●Constant-Current/Constant-Voltage operation with thermal regulation to maximize Rate TyWpiicthaolucthriasrkgoefcoyvcelreh(ea1t0in0g0.mAh battery) ● Preset 4.2V charge voltage with ±1% accuracy ● Automatic Recharge ● Two Status Indication for Charge status, no battery and battery failure indicators ● C/10 charge termination ● 55μA supply current in shutdown ● 2.9V trickle current charge threshold ● Soft-Start limits inrush current ● Battery Temperature Sensing ● Available in SOP8-PP package Typical charge cycle(1000mAh battery) Applications ●Cellular Telephones ●Digital Still Cameras ●MP3 Players ●Bluetooth Applications ●Portable Devices ●USB Bus-Powered Chargers V02 Page 1 of 18 TEL 13509685286 Q 1839845898 P尚in亿C微o电nf子igu 李ra华tion 1A Lithium Ion Battery Linear harger SX5058 SX5058 Pin Assignment Pin Num. Symbol Function Temperature sense input Connecting TEMP pin to NTC thermistor’s output in Lithium ion battery pack. If TEMP 1 TEMP pin’s voltage is below 45% or above 80% of supply voltage VCC, this means that battery’s temperature is too low or too high, charging is suspended. The temperature sense function can be disabled by grounding the TEMP pin. Constant Charge Current Setting and Charge Current Monitor Pin The charge current is programmed by connecting a resistor RPROG from this pin to GND. When in precharge mode, the PROG pin’s voltage is regulated to 0.1V. When charging in constant-current mode this pin’s voltage is regulated to 1V. In all modes during 2 PROG charging, the voltage on this pin can be used to measure the charge current using the following formula: IBAT = VPROG R PROG *1100 3 GND Ground Positive input supply voltage 4 VCC Provides power to the internal circuit. When VCC drops to within 80mV of the BAT pin voltage, the SX5058 enters low power sleep mode, dropping IBAT to less than 2μA. Battery connection Pin Connect the positive terminal of the battery to this pin. Dropping BAT pin’s current to 5 BAT less than 2μA when IC in disable mode or in sleep mode. BAT pin provides charge current to the battery and provides regulation voltage of 4.2V. Charge terminated status output 6 is pulled low by an internal switch to indicate a battery charge terminated; this means Charge termination. Otherwise pin is in high impedance state. Open-Drain charge status output 7 When the battery is being charged, the pin is pulled low by an internal switch, otherwise, pin is in high impedance state. Chip enable input A high input will put the device in the normal operating mode. Pulling the CE pin to low 8 CE level will put the SX5058 into disable mode. The CE pin can be driven by TTL or CMOS logic level. V02 Page 2 of 18 1A Lithium Ion Battery Linear harger SX5058 Block Diagram SX5058 V02 Page 3 of 18 TEL 13509685286 Q 1839845898 SX5058 Absolute Maximum Ratings Parameter Rating Unit Input supply voltage : VCC PROG pin voltage -0.3~8 V -0.3~VCC+0.3 V BAT pin voltage -0.3~7 V TEMP pin voltage -0.3~10 V pin voltage -0.3~10 V pin voltage -0.3~10 V CE pin voltage -0.3~10 V BAT pin current 1200 mA PROG pin current 1200 μA Maximum junction temperature 145 ℃ Operating ambient temperature :Topa -40~85 ℃ Storage temperature :Tstr -65~125 ℃ Soldering temperature and time +260(Recommended 10S) ℃ Caution: The absolute maximum ratings are rated values exceeding which the product could suffer physical damage. These values must therefore not be exceeded under any conditions. V02 Page 4 of 18 1A Lithium Ion Battery Linear harger SX5058 SX5058 Electrical Characteristics Symbol Parameter Condition Min Typ. Max Unit VCC ICC -IBAT VFLOAL IBAT Input supply voltage ● 4.0 5.0 8.0 V ●Charge mode, RPROG=1.1KΩ - 150 500 μA static current Regulated output voltage ●Standby mode(charge end) ●Shutdown mode(RPROG not connected, VCCVHIGH , it indicates that the battery temperature is too high or too low and the charge cycle is suspended. When VTEMP is between VLOW and VHIGH, charge cycle resumes. The battery temperature sense function can be disabled by connecting TEMP pin to GND. V02 Page 9 of 18 1A Lithium Ion Battery Linear harger SX5058 SX5058 Selecting R1 and R2 The values of R1 and R2 in the application circuit can be determined according to the assumed temperature monitor range and thermistor’s values. The Follows is an example: Assume temperature monitor range is TL~TH, ( TL<TH);the thermistor in battery has negative temperature coefficient(NTC, RTL is thermistor’s resistance at TL, RTH is the resistance at TH,so RTL>RTH,then at temperature TL, the voltage at TEMP pin is: At temperature TH, the voltage at TEMP pin is: We know VTEMPL=VHIGH=K2×Vcc (K2=0.8);VTEMPH=VLOW=K1×Vcc (K1=0.45) Then we can have: For example, NCP03YS110 , operating Temperature is -40℃ to 125℃. If using environment temperature is -25℃ to 125℃, then RTL is the value of the resistance of NCP03YS110 at -25℃, about 66.148Ω; RTH=is the value of the resistance of NCP03YS110 at 125℃, about 1.077Ω. Likewise, for positive temperature coefficient thermistor in battery, we have RTH>RTL and we can calculate: We can conclude that temperature monitor range is independent of power supply voltage VCC and it only depends on R1, R2, RTL and RTH: The values of RTH and RTL can be found in related battery handbook or deduced from testing data. In actual application, if only one terminal temperature is concerned (normally protecting overheating), there is no need to use R2 but R1. It becomes very simple to calculate R1 in this case. Under Voltage lockout (UVLO) An internal under voltage lockout circuit monitors the input voltage and keeps the charger in shutdown mode until VCC rises above the under voltage lockout threshold . If the UVLO comparator is tripped, the charger will not come out of shutdown mode until VCC rises 140mV above the battery voltage. Manual terminate At any time of the cycle of charging will put the SX5058 into disable mode to pull CE pin to GND, or remove RPROG (PROG pin is float). This made the battery drain current to less than 2μA and reducing the supply current to 55μA. To restart the charge cycle, set CE pin in high level or connect a programming resistor. If SX5058 in the under voltage Lockout mode, the and are all in high impedance state, or VCC is above BAT pin 140mV, or VCC is too low. Auto restart Once charge is been terminated, SX5058 immediately use a 1.8ms filter time( tRECHARGE )on the termination V02 Page 10 of 18 1A Lithium Ion Battery Linear harger SX5058 SX5058 comparator to constant monitor the voltage on BAT pin. If this voltage drops below the 4.02V recharge threshold (about between 80% and 90% of VCC), another charge cycle begins. This ensured the battery maintained (or approach) to a charge full status and avoid the requirement of restarting the periodic charging cycle. In the recharge cycle, pin enters a pulled down status. Fig.1 State diagram of a typical charge cycle Fig.2 Isolating with capacitive load on PROG Pin Stability Considerations In constant-current mode, the PROG pin is in the feedback loop, not the battery. The constant-current mode stability is affected by the impedance at the PROG pin. With no additional capacitance on the PROG pin, the charger is stable with program resistor values as high as 20KΩ. However, additional capacitance on this node reduces the maximum allowed program resistor. Therefore, if IPROG pin is loaded with a capacitance C, the following equation should be used to calculate the maximum resistance value for RPROG: As user, may think charge current is important, not instantaneous current. For example, to run a low current mode switch power which parallel connected with battery, the average current from BAT pin usually importance to instantaneous current. In this case, In order to measure average charge current or isolate capacitive load from IPROG pin, a simple RC filter can be used on PROG pin as shown in Figure 2. In order to ensure the stability add a 10KΩ resistor between PROG pin and filter capacitor. V02 Page 11 of 18 1A Lithium Ion Battery Linear harger SX5058 SX5058 Power dissipation The conditions that cause the SX5058 to reduce charge current through thermal feedback can be approximated by considering the power dissipated in the IC. Nearly all of this power dissipation is generated by the internal MOSFET-this is calculated to be approximately: PD (VCC VBAT ) X I BAT The approximate ambient temperature at which the thermal feedback begins to protect the IC is: TA 145C PDJA ; TA 145C (VCC VBAT ) X IBAT X JA For example: The SX5058 with 5V supply voltage through programmable provides full limiting current 800mA to a charge lithium-ion battery with 3.75V voltage. If JA is 150℃/W ( reference to PCB layout considerations), When SX5058 begins to decrease the charge current, the ambient temperature about: TA 145C (5V3.75V ) X (800mA) χ150C / W TA 145C 0.5W X 150C / W 145C 75C TA =65C SX5058 can work in the condition of the temperature is above 65℃, but the charge current will pull down to below 800mA. In a fixed ambient temperature, the charge current is calculated to be approximately : Just as Description of the Principle part talks about so, the current on PROG pin will reduce in proportion to the reduced charge current through thermal feedback. In SX5058 design applications don’t need to considerate the worst case of thermal condition, this point is importance, because if the junction temperature up to 145℃ ,IC will auto reduce the power dissipation. Thermal considerations Because of the small size of the thin SOP8 package, it is important to use a good thermal PC board layout to maximize the available charge current. The thermal path for the heat generated by the IC is from the die to the copper lead frame, through the package leads, (especially the ground lead) to the PC board copper. The PC board copper is the heat sink. The footprint copper pads should be as wide as possible and expand out to larger copper areas to spread and dissipate the heat to the surrounding ambient. Other heat sources on the board, not related to the charger, must also be considered when designing a PC board layout because they will affect overall temperature rise and the maximum charge current. Add thermal regulation current It will effective to decrease the power dissipation through reduce the voltage of both ends of the inner MOSFET. In the thermal regulation, this action of transporting current to battery will raise. One of the measure is through an external component(as a resistor or diode) to consume some power dissipation. For example: The SX5058 with 5V supply voltage through programmable provides full limiting current 800mA to a charge lithium-ion battery with 3.75V voltage. If JA is 125℃/W, so that at 25℃ ambient temperature, the charge current is calculated to be approximately : In order to increase the thermal regulation charge current, can decrease the power dissipation of the IC through reducing the voltage (as show fig.3) of both two ends of the resistor which connecting in series with a 5V AC adapter. With square equation to calculate IBAT : V02 Page 12 of 18 1A Lithium Ion Battery Linear harger SX5058 SX5058 If RCC=0.25Ω, VS=5V, VBAT=3.75V, TA=25℃ and JA =125℃/W, we can calculate the thermal regulation charge current: IBAT=948mA. It means that in this structure it can output 800mA full limiting charge current at more high ambient temperature environment. Although it can transport more energy and reduce the charge time in this application, but actually spread charge time, if SX5058 stay in under-voltage state, when VCC becomes too low in voltage mode. Fig.4 shows how the voltage reduced with increase RCC value in this circuit. This technique will act the best function when in order to maintain the minimize the dimension of the components and avoid voltage decreased to minimize RCC . Fig.3:A circuit to maximum the thermal regulation charge current Fig.4:The relationship curve between charge current with RCC VCC bypass capacitor Many types of capacitors can be used for input bypassing, however, caution must be exercised when using multilayer ceramic capacitors. Because of the self-resonant and high Q characteristics of some types of ceramic capacitors, high voltage transients can be generated under some start-up conditions, such as connecting the charger input to a live power source. Adding a 1.5Ω resistor in series with a ceramic capacitor will minimize start-up voltage transients. Charging Current Soft Start SX5058 includes a soft start circuit which used to maximize to reduce the surge current in the begging of charge cycle. When restart a new charge cycle, the charging current ramps up from 0 to the full charging current within 20μs. In the start process it can maximize to reduce the action which caused by surge current load. USB and Wall Adapter Power SX5058 allows charging from a USB port, a wall adapter can also be used to charge Li-Ion/Li-polymer batteries. Figure 5 shows an example of how to combine wall adapter and USB power inputs. A P-channel MOSFET, M1, is used to prevent back conducting into the USB port when a wall adapter is present and Schottky diode, D1, is used to prevent USB power loss through the 1KΩ pull-down resistor. Generally, AC adaptor is able to provide bigger much current than the value of specific current limiting which is 500mA for USB port. So can rise charge current to 600mA with using a N-MOSFET (MN1) and an additional set resistor value as high as 10KΩ. V02 Page 13 of 18 1A Lithium Ion Battery Linear harger SX5058 SX5058 Fig.5:Combining Wall Adapter and USB Power Typical Application Mainly used in Cellular telephones, MP3, MP4 players, digital still cameras, electronic dictionary, GPS, portable devices and vary chargers. 1. Suitable for the function of battery’s temperature detection, the application of the indicator of battery’s temperature anomaly and charge status. 2. Suitable for the application of USB power and the charge of wall adapter V02 Page 14 of 18 1A Lithium Ion Battery Linear harger SX5058 SX5058 3. Suitable for charge status indicator, which the application not need battery’s temperature detection. 4. Suitable for the application which not need charge status indicator and battery’s temperature detection. 5. Add a resistor for power dissipation, Red LED for charge status, green LED for charge terminate state V02 Page 15 of 18 1A Lithium Ion Battery Linear harger SX5058 SX5058 Board Layout Considerations ●RPROG at PROG pin should be as close to SX5058 as possible, also the parasitic capacitance at PROG pin should be kept as small as possible. ●The capacitance at VCC pin and BAT pin should be as close to SX5058 as possible. ● During charging, SX5058 ’s temperature may be high, the NTC thermistor should be placed far enough to SX5058 so that the thermistor can reflect the battery’s temperature correctly. ● It is very important to use a good thermal PC board layout to maximize charging current. The thermal path for the heat generated by the IC is from the die to the copper lead frame through the package lead (especially the ground lead) to the PC board copper, the PC board copper is the heat sink. The footprint copper pads should be as wide as possible and expand out to larger copper areas to spread and dissipate the heat to the surrounding ambient. Feed through vias to inner or backside copper layers are also useful in improving the overall thermal performance of the charger. Other heat sources on the board, not related to the charger, must also be considered when designing a PC board layout because they will affect overall temperature rise and the maximum charge current. ●The ability to deliver maximum charge current under all conditions require that the exposed metal pad on the back side of the SX5058 package be soldered to the PC board ground. Failure to make the thermal contact between the exposed pad on the backside of the package and the copper board will result in larger thermal resistance. V02 Page 16 of 18 1A Lithium Ion Battery Linear harger SX5058 Packaging Information: Packaging Type: SOP8-PP SX5058 Character A A1 B b c c1 D D1 E E1 F L G R 1  Dimension (mm) Min Max 1.350 1.750 0.1 0.3 1.27(Typ.) 0.330 0.510 0.9(Typ.) 1.0(Typ.) 5.8 6.2 3.202 3.402 3.800 4.000 2.313 2.513 4.7 5.1 0.675 0.725 0.32(Typ.) 0.15(Typ.) 7° ° 8 Dimension (Inches) Min Max 0.053 0.069 0.004 0.012 0.05(Typ.) 0.013 0.020 0.035(Typ.) 0.039(Typ.) 0.228 0.244 0.126 0.134 0.150 0.157 0.091 0.099 0.185 0.201 0.027 0.029 0.013(Typ.) 0.006(Typ.) 7° ° 8 V02 Page 17 of 18

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