A4055 AITSEMI | Alldatasheet
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AiT Semiconductor Inc. www.ait-ic.com A4055 BATTERY MANAGEMENT 800mA STANDALONE LINEAR LI-ION BATTERY CHARGER REV1.2 - OCT 2011 RELEASED, SEP 2018 UPDATED - - 1 - DESCRIPTION FEATURES The A4055 is a complete constant -current / constant-voltage linear c harger for single cell lithium-Ion batteries. No external sense resistor is needed, and no blocking diode is required due to the internal MOSFET architecture. Therma l 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 A4055 automatically terminates the charge cycle when the charge current drops to 1/10 the programmed value after the final float voltage is reached. When the input supply (wall adapter or USB supply) is removed, the A4055 automatically enters a low current state, drop ping the battery drain current to less than 2 μA. The A4055 can be put into shutdown mode, reducing the supply current to 25 μA. Other features include charge current monitor, under-voltage lockout, automatic recharge and a status pin to indicate charge termination and the presence of an input voltage. The A4055 is available in SOT-25 Package Programmable Charge Current Up to 800mA No MOSFET, Sense Resistor or Blocking Diode Required Preset 4.2V Charge Voltage with ±1% Accuracy Charge Current Monitor Output for Gas Gauging Thermal Regulation Maximize s Charge Rate Without Risk of Overheating Charges Single Cell Li -Ion Batteries directly from USB Port Over-Voltage Protect Automatic Recharge Charge Status Output Pin C/10 Charge Termination 25μA Supply Current in Shutdown 2.9V Trickle Charge Threshold Soft-Start Limits Inrush Current Available in SOT-25 Package APPLICATION Cellular and Smart Phones Charging Docks and Cradles Blue Tooth Applications PDAs MP3/MP4/MP5 Players TYPICAL APPLICATION 600mA Application Circuit
ORDERING INFORMATION
SPQ: 3,000pcs/Reel E5 A4055E5R A4055E5VR Note V: Halogen free package R: Tape & Reel AiT provides all RoHS products
AiT Semiconductor Inc. www.ait-ic.com A4055 BATTERY MANAGEMENT 800mA STANDALONE LINEAR LI-ION BATTERY CHARGER REV1.2 - OCT 2011 RELEASED, SEP 2018 UPDATED - - 2 - PIN DESCRIPTION Top View Pin # Symbol Function CHRG Open-Drain Charge Status Output. When the battery is charging, the CHRG pin is pulled low by an internal N-channel MOSFET. When the charge cycle is completed, a weak pull -down of approx imately 12μA is connected to the CHRG pin, indicating an “AC present” condition. When the A4055 detects an under-voltage lockout condition, CHRG is forced high impedance. 2 GND Ground.
3 BAT
Charge Current Output. Provides charge current to the batter y a nd regulates the final float voltage to 4.2V. An internal precision resistor divider from this pin sets the float voltage which is disconnected in shutdown mode.
4 VCC
Positive Input Supply Voltage. Provides power to the charg er. VCC can range from 4.25V to 6.5V and should be bypassed with at least a 1 μF capacitor. When V CC drops to within 30mV of the BAT pin voltage, the A4055 enters shutdown mode, dropping IBAT to less than 2μA.
5 PROG
Charge Current Program, Charge Current Monitor and Shutdown Pin. The charge current is programmed by connecting a 1% resistor, RPROG, to ground. When charging in constant-current mode, this pin servos to 1V. In all modes, the voltage on this pin can be used to measure the charge current using the following formula: IBAT = (VPROG/RPROG) •1000 The PROG pin can also be use d to shut down the charger. Disconnecting the program resistor from ground allows a 3μA current to pull the PROG pin high. When it reaches the 1.21V shutdown threshold voltage, the charger enters shutdown mode, charging stops and the input supply current drops to 25 μA. This pin is also clamped to approximately 2.4V. Driving this pin to vol tages beyond the clamp voltage will draw currents as high as 1.5mA. Reconnecting RPROG to ground will return the charger to normal operation.
AiT Semiconductor Inc. www.ait-ic.com A4055 BATTERY MANAGEMENT 800mA STANDALONE LINEAR LI-ION BATTERY CHARGER REV1.2 - OCT 2011 RELEASED, SEP 2018 UPDATED - - 3 - ABSOLUTE MAXIMUM RATINGSNOTE1 VCC Input Supply Voltage -0.3V to +10V PROG Voltage -0.3V to + VCC BAT Voltage -0.3V to 7V CHRG -0.3V to 10V BAT Short-Circuit Duration Continuous BAT Pin Current 800mA PROG Pin Current 800μA Maximum Junction Temperature 125°C Operating Temperature Range NOTE2 -40°C to 85°C Storage Temperature Range, -65°C to 125°C Lead Temperature (Soldering,10s) 300°C Thermal Resistance NOTE3 θJA, SOT-25 250°C/W θJC, SOT-25 130°C/W Stresses above may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other conditions beyond those indicated in the Electrical Characteristics are not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. NOTE1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. NOTE2: The A4055 is guaranteed to meet performance specifications from 0°C to 70°C. Specifications over the –40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. NOTE3: Thermal Resistance is specified with approximately 1 square of 1 oz copper.
AiT Semiconductor Inc. www.ait-ic.com A4055 BATTERY MANAGEMENT 800mA STANDALONE LINEAR LI-ION BATTERY CHARGER REV1.2 - OCT 2011 RELEASED, SEP 2018 UPDATED - - 4 - ELECTRICAL CHARACTERISTICSNOTE4 VCC=5V, TA= 25°C, unless otherwise noted Parameter Symbol Conditions Min Typ. Max Unit Charge Mode Supply CurrentNOTE5 ISPLYCHRG RPROG=2kΩ - 300 2000 μA RPROG =10kΩ - 2000 Charge Mode Battery Current IBATCHRG RPROG =2kΩ 465 500 535 mA RPROG =10kΩ 93 100 107 mA PROG Pin Voltage VPROGCHRG RPROG =2kΩ 0.93 1 1.07 V RPROG=10kΩ 0.93 1 1.07 V Standby Mode Supply Current ISPLYSTBY - 100 500 μA Standby Mode Battery Current IBATSTBY 0 -2.5 -6 μA Manual Shutdown Mode Supply Current ISPLYMSD - - 90 μA Manual Shutdown Mode Battery Current IBATMSD -2 0 2 μA PROG Pin Clamp Voltage VPROGCLMP 2 - 3 V Automatic Shutdown Mode Supply Current ISPLYASD - 25 50 μA Automatic Shutdown Mode Battery Current IBATASD -2 0 2 μA UVLO Mode Supply Current ISPLYUVLO - 25 50 μA UVLO Mode Battery Current IBATUVLO -2 - 2 μA Sleep Mode Battery Current IBATSLEEP -1 - 1 μA Float Voltage VFLOAT 4.158 4.2 4.242 V Trickle Charge Current ITRIKL RPROG=2kΩ 20 50 70 mA RPROG =10kΩ 5 10 15 mA Trickle Charge Threshold VTRIKL 2.8 2.9 3 V Trickle Charge Hysteresis VTRIKL, HYS 60 100 150 mV UVLO Threshold VUVLO 3.7 3.9 4.1 V UVLO Hysteresis VUVLO, HYS 150 200 300 mV Input Over-Voltage Protect Threshold VOVP 6.8 7 7.2 V Input Over-Voltage Protect Hysteresis VOVP, HYS - 200 - mV
AiT Semiconductor Inc. www.ait-ic.com A4055 BATTERY MANAGEMENT 800mA STANDALONE LINEAR LI-ION BATTERY CHARGER REV1.2 - OCT 2011 RELEASED, SEP 2018 UPDATED - - 5 - Parameter Symbol Conditions Min Typ. Max Unit Manual Shutdown Threshold, PROG rising VMSD, RISE 1.15 1.21 1.3 V Manual Shutdown Threshold, PROG falling VMSD, FALL 0.95 1.0 1.05 V Automatic Shutdown Threshold, BAT rising VASD, RISE 5 30 50 mV Automatic Shutdown Threshold, BAT falling VASD, FALL 70 100 140 mV C/10 Termination Current Threshold ITERM 85 100 115 mV Auto Recharge Battery Voltage VRECHRG 4 4.05 4.1 V CHRG Pin Weak Pull-down Current ICHRG 8 12 35 μA CHRG Pin Output Low Voltage VCHRG - 0.35 0.6 V Junction Temperature In Constant Temperature Mode TLIM - 120 - °C Power FET ON Resistance RON - 600 - mΩ Soft-Start Time tSS RPROG=2kΩ - 50 - μs Recharge Comparator Filter Time tRECHRG 0.75 2 4.5 ms Termination Comparator Filter Time tTERM 0.4 1 2.5 ms PROG Pin Pull-up Current IPROG - 3 - μA NOTE4: 100% production test at +25°C. Specifications over the temperature range are guaranteed by design and characterization. NOTE5: Supply current includes PROG pin current (approximately 100μA) but does not include any current delivered to the battery through the BAT pin (approximately 100mA).
AiT Semiconductor Inc. www.ait-ic.com A4055 BATTERY MANAGEMENT 800mA STANDALONE LINEAR LI-ION BATTERY CHARGER REV1.2 - OCT 2011 RELEASED, SEP 2018 UPDATED - - 10 - BLOCK DIAGRAM
AiT Semiconductor Inc. www.ait-ic.com A4055 BATTERY MANAGEMENT 800mA STANDALONE LINEAR LI-ION BATTERY CHARGER REV1.2 - OCT 2011 RELEASED, SEP 2018 UPDATED - - 11 - TYPICAL CIRCUIT 1. USB/Wall Adapter Power Li-Ion Charger 2. Full Featured Single Cell Li-Ion Charger 3. Using a Microprocessor to Determine CHRG State 4. Basic Li-Ion Charger with Reverse Polarity Input Protection 5. 800mA Li-Ion Charger with External Power Dissipation
AiT Semiconductor Inc. www.ait-ic.com A4055 BATTERY MANAGEMENT 800mA STANDALONE LINEAR LI-ION BATTERY CHARGER REV1.2 - OCT 2011 RELEASED, SEP 2018 UPDATED - - 12 - DETAILED INFORMATION The A4055 is a single cell Lithium-Ion battery charger using a constant-current / constant voltage algorithm. It can deliver up to 800mA of charge current (using a good thermal PCB layout) with a f inal float voltage accuracy of 1%. The A4055 includes an internal P -channel power MOSFET and thermal regulation circuitry. No blocking diode or external current sense resistor is required; thus, the basic charger circuit requires only two external components. Furthermore, the A4055 is capable of operating from a USB power source. Normal Charge Cycle A charge cycle begins when the voltage at the V CC pin rises above the UVLO threshold level and a 1% program resistor is connected 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 A4055 supplies approximately 1/10 the programmed charge current to bring the battery voltage up to a sa fe level for full current charging. When the BAT pin voltage rises above 2.9V, the charger enters constant -current mode, where the programmed charge current is supplied to the battery. If the battery voltage is above 2.9V at power-on, A4055 enters the constant-current mode immediately. Refer to Figure 1. When the BAT pin approaches the final float voltage (4.2V), the A4055 enters constant-voltage mode and the charge current begins to decrease. When the charge current drops to 1/10 of the programmed value, the charge cycle ends. Programming Charge Current The charge current is programmed 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 a re calculated using the following equations: The charge current out of the BAT pin can be determined at any time by monitoring the PROG pin voltage using the following equation:
AiT Semiconductor Inc. www.ait-ic.com A4055 BATTERY MANAGEMENT 800mA STANDALONE LINEAR LI-ION BATTERY CHARGER REV1.2 - OCT 2011 RELEASED, SEP 2018 UPDATED - - 13 - Charge Termination A charge cycle is terminated when the charge curren t falls to 1/10 the programmed value after the final float voltage is reached. This condition is detected 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 A4055 enters standby mode, where the input supply current drops to 100μA. (Note: C/10 termination is disabled in trickle charging mode). When charging, transient loads on the BAT pin can cause the PROG pin to fall below 100mV for short periods of time before the DC charge current has dropped to 1/10 the programmed value. The 1ms filter time (T TERM) on the termination comparator ensures that transient loads of this nature do not result in premature charge cycle termination. Once the average charge current drops b elow 1/10 the programmed value, the A4055 terminates the charge cycle and ceases to provide any current through the BAT pin. In this state, all loads on the BAT pin must be supplied by the battery. Figure1 State Diagram of A4055 Charge Cycle Charge Status Indicator (CHRG) The charge status output has three different states: strong pull -down (~10mA), weak pull -down (~12μA) and high impedance. The strong pull -down state indicates that the A4055 is in a charge cycle. Once the charge cycle has terminated, t he pin state is deter -mined by under -voltage lockout conditions. A weak pull -down indicates that V CC meets the UVLO conditions and the A4055 is ready to charge. High impedance indicates that the A4055 is in under-voltage lockout mode: either VCC is less than 100mV above the BAT pin voltage or insufficient voltage is applied to the VCC pin. A microprocessor can be used to distinguish between these three states—the application circuit of this method is shown in the Typical Applications section.
AiT Semiconductor Inc. www.ait-ic.com A4055 BATTERY MANAGEMENT 800mA STANDALONE LINEAR LI-ION BATTERY CHARGER REV1.2 - OCT 2011 RELEASED, SEP 2018 UPDATED - - 14 - Manual Shutdown At any point in the charge cycle, the A4055 can be put into shutdown mode by removing R PROG thus floating the PROG pin. This reduces the battery drain current to less than 2μA and the supply current to less than 50μA. A new charge cycle can be initiated 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 UVLO conditions. The CHRG pin is in a high impedance state if the A4055 is in under-voltage lockout mode: either VCC is within 100mV of the BAT pin voltage or insufficient voltage is applied to the VCC pin. Over-Voltage Protect The A4055 has an internal Over -Voltage Protect comparator, once the input voltage VCC rises above 7V (VOVP), this comparator will shut dow n the chip. This feature can pre -vent the A4055 from the over -voltage stress due to the input transient at hot p lug in. In this state, the CHRG pin will be high impedance. Once the VCC falls back to safe range (VOVP - VOVP, HYS), normal operation continues. Automatic Recharge Once the charge cycle is terminated, the A4055 continuously monitors the voltage on the BAT pin using a comparator with a 2ms filter time (TRECHRG). A charge cycle restarts when the battery voltage falls below 4.05V (which corresponds to approximately 80% to 90% battery capacity). This ensures that the battery is kept at or near a fully charged condition and eliminates the need for periodic charge cycle initiations. CHRG output enters a strong pull-down state during recharge cycles. 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 present, an output capacitor is recommended to reduce ripple voltage. When using high value, low ESR ceramic capacitors, it is recommended to add a 1Ω resistor in series with the capacitor. No series resistor is needed if tantalum capacitors are used. 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 a t the PROG pin. With no additional capacitance on the PROG pin, the charger is stable with program resistor values as high as 20k. However, additional capacitance on this node reduces the maximum allowed program resistor thus it should be avoided. Average, rather than instantaneous, charge current may be of interest to the user. For example, if a switching power supply opera -ting in low current mode is connected in parallel with the battery, the average current being pulled out of the BAT pin is typically o f more interest than the instantaneous current pulses. In such a case, a simple RC filter can be used on the PROG pin to measure the average battery current as shown in
dissipation when the junction temperature reaches approximately 120°C. layout because they will affect overall temperature rise and the maximum charge current. The following table lists thermal resistance for several different board sizes and copper areas. All measurements were taken in still air on 3/32" FR-4 board with the device mounted on topside. Table 1. Measured Thermal Resistance (2-Layer BoardNOTE6)
Table 2. Measured Thermal Resistance (4-Layer BoardNOTE7)
2 NOTE8
capacitor will minimize start-up voltage transients.
AiT Semiconductor Inc. www.ait-ic.com A4055 BATTERY MANAGEMENT 800mA STANDALONE LINEAR LI-ION BATTERY CHARGER REV1.2 - OCT 2011 RELEASED, SEP 2018 UPDATED - - 18 -
PACKAGE INFORMATION
Dimension in SOT-25 Package (Unit: mm) Symbol Millimeters Inches Min Max Min Max A 0.889 1.295 0.035 0.051 A1 0.000 0.152 0.000 0.006 B 1.397 1.803 0.055 0.071 b 0.356 0.559 0.014 0.022 C 2.591 2.997 0.102 0.118 D 2.692 3.099 0.106 0.122 e 0.838 1.041 0.033 0.041 H 0.080 0.254 0.003 0.010 L 0.300 0.610 0.012 0.024
AiT Semiconductor Inc. www.ait-ic.com A4055 BATTERY MANAGEMENT 800mA STANDALONE LINEAR LI-ION BATTERY CHARGER REV1.2 - OCT 2011 RELEASED, SEP 2018 UPDATED - - 19 - IMPORTANT NOTICE AiT Semiconductor Inc . (AiT) reserves the right to make changes to any its product, specifications, to discontinue any integrated circuit product or service without notice, and advises its customers to obtain the latest version of relevant information to verify, before placing orders, that the information being relied on is current. AiT Semiconductor Inc .'s integrated circuit products are not designed, intended, authorized, or warranted to be suitable for use in life support applications, devices or systems or other critical applications. Use of AiT products in such applications is understood to be fully at the risk of the customer. As used herein may involve potential risks of death, personal inju ry, or server property, or environmental damage. In order to minimize risks associated with the customer's applications, the customer should provide adequate design and operating safeguards. AiT Semiconductor Inc . assumes to no liability to customer product design or application support. AiT warrants the performance of its products of the specifications applicable at the time of sale.