XZ4054充电IC
Standalone Linear Li-Ion Battery Charger in ThinSOT General Description Features XZ4054D is a constant-
current/constant-voltage linear Programmable Charge Current Up to 800mA charger for single cell lithium-ion batteries. Its Thin SOT No MOSFET, Sen Resistor or Blocking package and low external component count make the Diode Required XZ4054D ideally suited for portable applications. Complete Linear Charger in ThinSOT Package Furthermore, the XZ4054D is specifically designed to work for Single Cell Lithium-Ion Batteries within USB power specifications. Constant-Current/Constant-Voltage Operation No external n resistor is needed, and no blocking with Thermal Regulation to Maximize Charge diode is required due to the internal MOSFET architecture. Rate Without Risk of Overheating Thermal feedback regulates the charge current to limit the Charges Single Cell Li-Ion Batteries Directly die temperature during high power operation or high from USB Port ambient temperature. The charge voltage is fixed at 4.2V, Pret
4.34V Charge Voltage with ±1% and the charge current can be programmed externally with Accuracy a single resistor. The XZ4054 automatically terminates he Automatic Recharge charge cycle when the c
harge current drops to 1/10th the Charge Status Output Pin programmed value after the final float voltage is reached. C/10 Charge Termination When the input supply (wall adapter or USB supply) is 55µA Supply Current in Shutdown removed, the XZ4054 automatically enters a low current 2.9V Trickle Charge Threshold state, dropping the battery drain current to less than Soft-Start Limits Inrush Current 2µA.The XZ4054D can be put into shutdown mode, Available in 5-Lead SOT-23 Package reducing the supply current to 55µA. Applications Other features include charge current monitor, Cellular Telephones, PDAs, MP3 Players undervoltage lockout, automatic recharge and a status pin Charging Docks and Cradles Bluetooth Applications 600mA Single Cell Li-Ion Charger
1μF
V IN 4.5V TO 6.5V
4
VCC
3
BAT XZ 4054D PROG 5 GND 2
1.65K
600mA 4.2V Li-Ion BATTERY
Complete Charge Cycle (750mAh Battery) 700 CONSTANT CURRENT 4.75 CONSTANT 4.5 CONSTANT VOLTAGAE 500 POWER 4.25 4.0
600
400
300
200
100
V CC θ JA =130 ℃ /W R PROG =1.65K CHARGE T A =25 ℃ TERMINATED 0 0.25 0.5 0.75 1.0 1.25 1.5 1.75 2.0
TIME(HOURS)
陆谷孙=5V
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XZ4054D
3.75
scenery什么意思3.5
3.25
Pin Configuration
Pin Assignment
Pin
SOT23-5
CHRG
GND
BAT
2
1
Symbol
2 GND Ground θ JA
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5 PROG 3 4 VCC
3 BAT Charge Current Output
4 VCC Positive Input Supply Voltage
5 PROG Charge Current Program
Description
1 CHRG Open-Drain Charge Status Output
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XZ4054D
Block Diagram
120 ℃
T DIE
CHRG 1
lick you climactic
TA
SHDN
CA
C1
C2
C3
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1x
TO BAT 2.9V 5
3μA
MA
PROG
4
R3 1V R4 0.1V R5
VCC
VCC
VA
5μA
英译汉翻译器下载REF 1.22V工作时间英文
GND 2
1000x BAT 3 R1
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R2
Absolute Maximum Ratings Parameter Ratings Input Supply Voltage (VCC) － 0.3V ～ 10V PROG -0.3V ～ Vcc ＋ 0.3V BAT -0.3V ～ 7V CHRG -0.3V ～ 10V BAT Short-Circuit Duration Continuous BAT Pin Current 800mA PROG Pin Current
800μA Maximum Junction Temperature 125 ℃ Operating Ambient Temperature Range -40 ℃～ 85 ℃ Storage Temperature Range -65 ℃～ 125 ℃ Lead Temperature (Soldering, 10 c) 260 ℃ Caution: The absolute maximum ratings are rated values exceeding which the product could suffer physical damage. The values must therefore not be exceeded under any conditions.
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XZ4054D
Electrical Characteristics SYMBOL PARAMETER CONDITIONS MIN TYP MAX Unit VCC Input Sup ply Voltage ● 4.25 6.5 V ●Charge Mode ， R PROG =10KΩ - 300 2000 µA ●Standby Mode (Charge - 200 500 µA I CC Input Supply Current Terminated ) Shutdown Mode （ R PROG Not - 25 50 µA Connected ， VCC<V BAT ） V FLOAT Regulated Output (Float) Voltage 0 ℃ ≤T A ≤85 ℃ ,I BAT =40mA 4. 158 4.2 4.242 V ●R PROG =10KΩ,Current Mode 93 100 107 mA ●R PROG =2KΩ,Current Mode 465 500 535 mA I BAT BAT Pin Current ●Standby Mod e ， V BAT ＝ 4.2V 0 -2.5 -6 µA Shutdown Mode （ R PROG Not - ±1 ±2 µA Connected ） Sleep Mode, VCC ＝ 0V ±1 ±2 µA I TRILK Trickle Charge C urrent ●V BAT ＜ V TRILK , R PROG ＝ 2KΩ 20 45 70 mA V TRILK Trickle Charge Threshold Voltage R PROG ＝ 10KΩ, V BAT Rising 2.8 2.9 3.0 V V TR HYS Trickle C
harge Hysteresis Voltage R PROG ＝ 10KΩ 60 80 110 mV VCC Undervoltage Lockout V UV ●From VCC Low to High 3.7 3.8 3.92 V Thresh old VCC Undervoltage Lockout V UVHYS ● 150 200 300 mV Hysteresis Manual Shutdown Threshold ●PROG Pin Rising 1.15 1.21 1.30 V V MSD Voltage ●PROG Pin Falling 0.9 1.0 1.1 V VCC-V BAT Lockout Threshold VCC from Low to High 70 100 140 mV V ADS Voltage VCC from High to Low 5 30 50 mV
●R C/10 Termination Current Threshold PROG ＝ 10KΩ 0.085 0.10 0.115 mA I TERM ●R PROG ＝ 2KΩ 0.085 0.10 0.115 mA V PROG PROG Pin Voltag
e ●R PROG ＝ 10KΩ, Current Mode 0.93 1.0 1.07 V I CHRG CHRG Pin Weak Pull-Down Current V CHRG ＝ 5V 8 20 35 µA V CHRG CHRG Pin Output L ow I CHRG ＝ 5mA 0.35 0.6 V Recharge Battery Threshold V RECHRG V FLOAT － V RECHRG 100 150 200 mV Voltage Junction Temperature in Const ant T LIM - 120 - ℃ Temperature Mode Power FET “ON” Resistance R ON - 600 - mΩ (Between VCC and BAT) T SS Soft-Start Time I BAT ＝ 0 to I BAT ＝ 1000V/ R PROG 100 µS T RE Recharge Comparator Filter Time V BAT High to Low 0.75 2 4.5 mS T TERM Termination Comparator Filter Time I BA T Falling Below I CHG /10 400 1000 2500 µS I PROG PROG Pin Pull-Up Current - 3 - µA Note: The ● denotes specifications which apply over the full ope rating temperature rang, otherwi specifications are at T A =25 ℃， V CC =5V ， unless otherwi
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XZ4054D
Typical performance characteristics
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XZ4054D
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XZ4054D
Description of the Principle The XZ4054D is a single cell lithium-ion battery charger using a consta n
t-current/constant-voltage algorithm. It can deliver up to 800mA of charge current (using a good thermal PCB layout) with a final float voltage accuracy of±1%. The XZ4054D includes an internal P-channel power MOSFET and thermal regulation circuitry. No blocking diode or external current n resistor is r equired; thus, the basic charger circuit requires only two external components. Furthermore, the XZ4054D is capable of operating from a USB power sourc e. 1.Normal Charge Cycle A charge cycle begins when the voltage at the VCC pin ris above the UVLO threshold level and a 1% program resistor is conn ected from the PROG pin to ground or when a battery is connected to the charger output. If the BAT pin is less than 2.9V, the charger enters trickle charge mode. In this mode, the KT4054 supplies approximately 1/10 the programmed charge current to bring the battery voltage up to a safe level for full current charging. When the BAT pin voltage ris above 2.9V, the charger enters constant-current mode, where the programmed charge current is supplied to the battery. When the BAT pin approaches the final float voltage (4.2V), the XZ4054D enters constant-voltage mode and the charge current begins to decreas e. When the charge current drops to 1/10 of the programmed value, the charge cycle ends. 2.Programming Charge Current The charge current is program med using a single resistor from the PROG pin to ground. The battery charge current is 1000 times the current out of the PROG pin. The program resistor and the charge current are calculated using the following equations: R PROG =1000V/I CHG , I CHG =1000V/ R PR
OG The charge current out of the BAT pin can be determined at any time by monitoring the PROG pin voltage using the following equation: I BAT =1000* V PROG / R PROG 3.Charge Terminatio n A charge cycle is terminated when the charge current falls to 1/10th the programmed value after the final float voltage is reached. This condition is detect ed by using an internal, filtered comparator to monitor the PROG pin. When the PROG pin voltage falls below 100mV for longer than t TERM (typically 1ms ), charging is terminated. The charge current is latched off and the XZ4054D enters standby mode, where the input supply current drops to 200µA.(Note: C /10 termination is disabled in trickle charging and thermal limiting modes). When charging, transient loads on the BAT pin can cau the PROG pin to fall b elow 100mV for short periods of time before the DC charge current has dropped to 1/10th the programmed value. The 1ms filter time (t TERM ) on the ter mination comparator ensures that transient loads of this nature do not result in premature charge cycle termination. Once the average charge current drop s below 1/10th the programmed value, the XZ4054D terminates the charge cycle and ceas to provide any current through the BAT pin. In this state, all lo ads on the BAT pin must be supplied by the battery. The XZ4054D constantly monitors the BAT pin voltage in standby mode. If this voltage drops below th e 4.05V recharge threshold (V RECHRG ), another charge cycle begins and current is once again supplied to the battery. To manually restart a charge cycl e when in standby mode, the input voltage must be removed and reap
plied, or the charger must be shut down and restarted using the PROG pin. Figure 1 shows the state diagram of a typical charge cycle. V03 Page 7 of 15
XZ4054D
4.Charge Status Indicator (CHRG) The charge status output has three different states: strong pull-down (~10mA), weak pull-down (~20µA) and high impedance. The strong pull-down state indicates that the XZ4054D is in a charge cycle. Once the charge cycle has terminated, the pin state is determined by undervoltage lockout conditions. A weak pull-down indicates that VCC meets the UVLO conditions and the XZ4054D is ready to charge. High impedance indicates that the XZ4054D is in undervoltage lockout mode: either VCC is less than 100mV above the B AT pin voltage or insufficient voltage is applied to the VCC pin. A microprocessor can be ud to distinguish between the three states—this method is dis cusd in the Applications Information ction.九月英文缩写
5.Thermal Limiting An internal thermal feedback loop reduces the programmed charge current if the die tem perature attempts to ri above a pret value of approximately 120°C. This feature protects the XZ4054D from excessive temperature and allows the u r to push the limits of the power handli
ng capability of a given circuit board without risk of damaging the XZ4054D . The charge current can be t accordin g to typical (not worst-ca) ambient temperature with the assurance that the charger will automatically reduce the current in worst-ca conditions. ThinS OT power considerations are discusd further in the Applications Information ction.
6.Undervoltage Lockout (UVLO) An internal undervoltage lockout cir cuit monitors the input voltage and keeps the charger in shutdown mode until VCC ris above the undervoltage lockout threshold. The UVLO circuit has a built-in hysteresis of 200mV. Furthermore, to protect against rever current in the power MOSFET, the UVLO circuit keeps the charger in shutdown mode if VCC falls to within 30mV of the battery voltage. If the UVLO comparator is tripped, the charger will not come out of shutdown mode until VCC ris 100m V above the battery voltage.
7.Manual Shutdown At any point in the charge cycle, the XZ4054D can be put into shutdown mode by removing RPROG thu s floating the PROG pin. This reduces the battery drain current to less than 2uA and the supply current to less than 50uA. A new charge cycle can be initiat ed by reconnecting the program resistor. In manual shutdown, the CHRG pin is in a weak pull-down state as long as VCC is high enough to exceed the UV LO conditions. The CHRG pin is in a high impedance state if the XZ4054D is in undervoltage lockout mode: either VCC is within 100mV of the BAT pin volt age or 煎熬的意思
insufficient voltage is applied to the VCC pin.
8.Automatic Recharge Once the charge cycle is terminated, the XZ4054D continuously monitors the vo ltage on the BAT pin using a comparator with a 2ms filter time (t RECHARGE ). A charge cycle restarts when the battery voltage falls below 4.05V (which c orresponds to approximately 80% to 90% battery capacity).This ensures that the battery is kept at or near a fully charged condition and eliminates the nee d for periodic charge cycle initiations. CHRG output enters a strong pull-down state during recharge cycle
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XZ4054D
POWER ON
Application Information
SHUNDOWN MODE I CC DROPS TO<25μA CHRG:HI-Z IN UVLO WEAK PULL-DOWN OTHERWISE
PROG FLOATED OR UVLO CONDITION
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CHARGE MODE FULL CURRENT CHRG:STRONG PULL-DOWN
BAT<2.9V
TRICKLE CHARGE MODE 1/10 TH FULL CURRENT CHRG:STRONG PULL-DOWN
zimmermanBAT>2.9V
STANDBY MODE NO CHARGE CURRENT CHRG:WEAK PULL-DOWN
PROG<100mV
2.9V4.05V
BAT>2.9V
Fig.1 State Diagram of a Typical Charge Cycle
1.Stability Considerations The constant-voltage mode feedback loop is stable without an output capacitor provided a battery is connected to the charger output. With no battery prent, an output capacitor is recommended to reduce ripple voltage (as Fig.2). When using high value, low ESR ceramic capacitors, it is recommended to add a 1Ω resistor in ries with the capacitor. No ries resistor is needed if tantalum capacitors are ud. 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. The pole frequency at the PROG pin should be kept above 100KHz. Therefore, if I PROG pin is loaded with a capacitance C PROG , the following equation should be ud to calculate the maximum resistance value for R PROG ：
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XZ4054D
XZ4054D
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Fig.2 Average, rather than instantaneous, charge current may be of interest to the ur. For example, if a switching power supply operating in low current mode is connected in parallel with the battery, the average current being pulled out of the BAT pin is typically of more interest than the instantaneous current puls. In such a ca, a simple RC filter can be ud on the PROG pin to measure the average battery current as shown in Fig.3. A 10KΩ resistor has been added between the PROG pin and the filter capacitor to ensure stability.
有限公司英文Fig.3 Isolating Capacitive Load on PROG Pin and Filtering 2.Power dissipation The conditions that cau the XZ4054 D to reduce charge curren t through thermal feedback can be approximated by considering the power dissipated in the IC. Nearly all of this power dissipation is generated by the inte rnal MOSFET-this is calculated to be approximately: P D (V CC V BAT ) * I BAT Where P D is the power dissipated, V CC is the input supply voltage, V B AT is the battery voltage and I BAT is the charge current. The approximate ambient temperature at which the thermal feedback begins to protect the IC is: T A 120 C P D JA 120 C (V CC V BAT ) * I BAT * JA For example: The KT4054 with 5V supply voltage through programmable provides full limiting cur rent 400mA to a charge lithium-ion battery with 3.75V voltage. If JA is 150 ℃ /W ( reference to PCB layout considerations), When KT4054 begins to decr ea the charge current, the ambient temperature about: T A =120 ℃-(
5-3.75V)*(400mA)*150 ℃ /W = 120 ℃-0.5W* 150 ℃ /W=120 ℃-75 ℃ =45 ℃ K T4054 can work in the condition of the temperature is above 45 ℃ , the charge current is calculated to be approximately : I= 120℃-T A BAT (VCC-V)*θ BA TJA Using the previous example with an ambient temperature of 60 ℃ , the charge current will be reduced to approximately: I==320mA 120℃-60℃ BAT ( 5V-3.75V)*150℃/W
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XZ4054D
Moreover, when thermal feedback reduces the charge current, the voltage at the PROG pin is also reduced proportionally as discusd in the operation ction. It is important to remember that XZ4054D applications do not need to be designed for worst-ca thermal conditions since the IC will automatically reduce power dissipation when the junction temperature reaches approximately120 ℃ . 3.Thermal c onsiderations Becau of the small size of the thinSOT package, it is important to u 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 foot
print 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 w hen designing a PC board layout becau they will affect overall temperature ri and the maximum charge current. The following table lists thermal resist ance for veral different board sizes and copper areas. All measurements were taken in still air on2/32” FR-4 board with the device mounted on topside. Table.1 Measured Thermal resistance(2-layer board: each layer us one ounce copper Copper area Board areaThermal resistance TopsideBack side 2 （ mm 2 ）（ mm 2 （ mm ） junction-to ambient （℃ /W ）） 2500 2500 2500 125 1000 2500 2500 125 225 2500 2500 130 100 2500 2500 135 50 2500 2500 150 Table.2 Measured Thermal resistance (4-layer board: Top and bottom layers u two copper, inner layers u one ounce copper;10.0 mm2 total copper area) Copper area Board area Thermal resistance junction-to （ mm 2 ）（ mm 2 ） ambient （℃ /W ） 2500 2500 80 4.Increasi ng thermal regulation current It will effective to decrea the power dissipation through reduce the voltage of both ends of the inner MOSFET. In the ther mal regulation, this action of transporting current to battery will rai. One of the measure is through an external component (as a resistor or diode) to cons ume some power dissipation. For example: The XZ4054D with 5V supply voltage through programmable provides full limiting current 800mA to a charge lit hium-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 : I==6 08mA 120℃-25℃ BAT (5V-3.75V)*125℃/W By dropping voltage across a resistor in ries with a 5V wall adapter (shown in Fig.4), the on-chip power diss ipation can be decread, thus increasing the thermally regulated charge current: I= 120℃-25℃ BAT (V-IR-V)* SBATCCBATJA Θ V03 Page 11 of 15
XZ4054D
Fig.4 A circuit to maximize thermal mode charge current Solving for I BAT using the quadratic formula: (V-V)-(V-V) 2
4R(120 CCA ℃-T) SBATSBAT Θ I= JA BAT 2R CC If R CC =0.25Ω, V S =5V, V BAT =3.75V, T A =25 ℃ and JA =125 ℃/W, we can calculate the thermal regulation charge current: I BAT ＝ 708.4mA. While this application delivers more energy
to the battery and reduces charge time in thermal mode, it may actually lengthen charge time in voltage mode if VCC becomes low enough to the KT4054 into dropout. Fig.5 shows how this circuit can result in dropout as R CC becomes large. This technique works best when R CC values are minimized to keep component size small and avoid dropout. Remember to choo a resistor with ad
equate power handling capability.
Fig.5 Charge current vs R CC 5.V CC bypass capacitor Many types of capacitors can be ud for input bypassing, however, caution must be exercid when using multilayer ceramic capacitors. Becau of the lf-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 resis tor in ries with an X5R ceramic capacitor will minimize start-up voltage transients. V03 Pag e 12 of 15
XZ4054D
6.Charging Current Soft Start XZ4054D includes a soft start circuit which ud to maximize to redu ce 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 ove r a period of approximately 100µs. This has the effect of minimizing the transient current load on the power supply during start-up.
7.CHRG status output Pi n
