ETA3001 ETA | Alldatasheet
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www.eta-semi.com 1 Empower, Transcend, Achieve! ETA3001 Rev 1.2 Inductive Cell Balancer IC with Balancing Current Up to 2A DESCRIPTION FEATURES ETA3001 is an inductive cell balancer. Unlike conventional passive balancing technique, ETA3001 utilizes a control scheme with an inductor to shuffle currents between two cells until the cells are balanced. Due to the switching nature, the heat and power dissipation generated in conventional li near balance technique are greatly reduced. The balance time is also significantly reduced due to higher balancing current not being limited by package thermal dissipation. ETA3001 consumes only 2µA ultra -low current from batteries in standby mode, extending the battery shelf time. The final balanced voltages of both cells are also highly accurate which enhances the performance and lifetime for the batteries connected in series. ETA3001 can also be used in multiple cells stacking with even number of cells. ETA3001 includes protection features similar to precondition in battery charging, that is when one cell’s voltage is grossly lower than the other, the balancing current is reduced to a safe level until the lower voltage cell is charged up. ETA3001 is available in DFN2x2-8 package. Inductive, switching control scheme Up to 90% charger transfer efficiency Accurate balanced voltages down to 30mV Auto detect unbalance and auto balance Low sleeping supply current, 2µA Programmable balancing current up to 2A Precondition balancing current Status indications Battery over voltage protection Support small size inductor
APPLICATIONS
Multi-cells System Battery Pack Portable Equipment and Instrumentation Battery Backup Systems E-Cigarette TYPICAL APPLICATION ETA3001 BATP HGATE BIAS SW LGATE BATN BATC ISET 10uF 10uF 1uH 10nF optional 10uF 100Ω Rs Li Battery Li Battery TVS TVS Figure 1: Typical Application Circuit
www.eta-semi.com 2 Empower, Transcend, Achieve! ETA3001 Rev 1.2 ORDERING INFORMATION PART No. PACKAGE TOP MARK Pcs/Reel ETA3001D2I DFN2x2-8L G3YW 3000 PIN CONFIGURATION DFN2x2-8 BATP HGATE SW LGATE BATC ISET BIAS BATN ETA3001 Top View GND ABSOLUTE MAXIMUM RATINGS (Note: Exceeding these limits may damage the device. Exposure to absolute maximum rating conditions for long periods may affect device reliability.) SW, ISET Voltage to BATN………….…..-0.3V to 12V BIAS, HGATE to SW Voltage………...…-0.3V to 6V LGATE to BATN Voltage……………...…-0.3V to 6V SW, BATC, BATP to BATN current…Internally limited Thermal Resistance θJC θJA Lead Temperature (Soldering,10sec)…………260°C ESD CDM (Charged Device Mode)………...……1KV Recommended Operating Conditions (Note: The device is not guaranteed to function outside its operating conditions.) Junction Temperature Range ……....–40C to 125C
ELECTRICAL CHARACTERISTICS
(TA=25 OC, L = 1µH, CBOT=CTOP=10µF if not specified) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT SUPPLY ISUPPLY Quiescent current VBATP=8V, VBATP-VBATC=VBATC-VBATN 2 µA Operating supply current VBATP=8V, in balancing mode, No Switching 900 µA VBATP VBATP operating voltage 10 V VBATC VBATC operating voltage 5 V UVLO Under lock-out voltage threshold VBATP Rising 3.75 V UVLO_HYS UVLD hysteresis 200 mV DETECTION TSLEEP Detection interval timer Part sleeps during TSLEEP 2 S TALLOW Unbalance detection Unbalance status is 3.85 mS
www.eta-semi.com 3 Empower, Transcend, Achieve! ETA3001 Rev 1.2 acknowledgment timer accepted after TALLOW when enter CHECK state. TCHECK Maximum unbalance checking timer IC get back to sleeping mode if don’t detect unbalance after TCHECK 7.68 mS TDONE Finishing Timer Maximum switching skip before enter sleep mode 62 mS VKICK Unbalance detection threshold Balancing only work if OVP>VBATP>UVLO and VKICK Detected between 2 cells 100 mV VERROR Balancing Accuracy Error voltage between 2 cells after balancing finish -70 70 mV BALANCE CONTROLLER FREQ Switching Frequency PWM Clock 1 MHz IAVERAGE Average Inductor current Regulation RS = 50mΩ 1 A IPRECOND Precondition current Regulation RS = 50mΩ 100 mA BATTERY PROTECTION TOP_OVP Top Cell over voltage protection threshold V(BATP-BATC) Rising 5 V TOP_OVP_HYST TOP_OVP hysteresis V(BATP-BATC)Falling 350 mV BOT_OVP Bottom Cell over voltage protection threshold V(BATC-BATN) Rising 5 V BOT_OVP_HYST BATC_OVP hysteresis V(BATC-BATN) Falling 350 mV TOP_PRECOND Top battery precondition threshold V(BATP-BATC) Rising 2.8 V TOP_PREC_HYS T TOP_PRECOND hysteresis V(BATP-BATC) Falling 150 mV BOT_PRECOND Bottom battery precondition threshold V(BATC-BATN) Rising 2.8 V BOT_PREC_HYS T BOT_PRECOND hysteresis V(BATC-BATN) Falling 150 mV BALANCE PROTECTION TOP_ILIM Top cell drive current limit DOWN direction: V(BATP-BATC)> V(BATC-BATN) 4.5 A BOT_ILIM Lower cell drive current limit UP direction: V(BATP-BATC)< V(BATC-BATN) 4.5 A THERMAL SHUTDOWN TSD Thermal shutdown 160 C
www.eta-semi.com 4 Empower, Transcend, Achieve! ETA3001 Rev 1.2 TSD_HYST TSD Hysteresis 30 C PIN DESCRIPTION PIN# NAME DESCRIPTION 1 BATP Sense voltage input for top cell. Connect a 10µ F capacitor between BATP and BATC. 2 HGATE Control high side external MOSFET. 3 SW Switching node. Connected to an inductor. 4 LGATE Control low side external MOSFET. 5 BATN Negative terminal sense voltage input and common Ground pin. 6 BIAS Bias pin. Connect a 10nF capacitor from BIAS to SW.
7 ISET
Balancing current setting pin. Connect a resistor from SW to an inductor to program the balancing current. Under an extremely high noise environment, a 1nF capacitor between ISET pin and SW pin can improve the ISET voltage stability, so a capacitor position res ervation here is recommended. 8 BATC Sense voltage inpu t for bottom cell. Connect a 10µ F capacitor between BATC and BATN. Exposed Pad EP Connect it to GND. FUNCTIONAL BLOCK DIAGRAM ETA3001 Bandgap & VDD & BIAS & OVP & TSD 1uA UVLO Timer Control Balance Current Sense Battery Sense VDD ISET BATP Balance Control BATC BIAS Upper Cell Driver Lower Cell Driver SW HGATE LGATE BATN Figure 2: Functional Block Diagram
www.eta-semi.com 5 Empower, Transcend, Achieve! ETA3001 Rev 1.2 TYPICAL PERFORMANCE CHARACTERISTICS (TA=25C, unless otherwise specified) 0.5 1.5 2.5 0 2 4 6 8 10 IQ(uA) VBATP(V) IQ Vs. VBATP Vtop=Vbot 500 1000 1500 2000 2500 3000 0 20 40 60 80 100 120 140 160 Average Inductor Current(mA) Rs(mΩ) Average Inductor Current Vs. Rs UP:Vbot=4.2V,Vtop=3V DOWN:Vbot=3V,Vtop=4.2V 100 200 300 400 500 600 700 800 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 IBAT(mA) VTOP(mV) IBAT Vs. VTOP Itop Ibot UP:Rs=50mΩ,Vbot=4.4V 100 200 300 400 500 600 700 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 IBAT(mA) VBOT(mV) IBAT Vs. VBOT Ibot Itop DOWN:Rs=50mΩ,Vtop=4.4V -0.6 -0.4 -0.2 0.2 0.4 0.6 0.8 2.5 3.5 4.5 0 50 100 150 200 IBAT(A) VBATV) Time(minutes) Balancing Without Charger Vbot Vtop Itop Ibot DOWN: Start from Vtop=4.2V, Vbot=2.4V, 2 18650 in series -0.8 -0.6 -0.4 -0.2 0.2 0.4 0.6 0.8 1.2 1.4 1.6 0.5 1.5 2.5 3.5 4.5 0 20 40 60 80 100 120 IBAT(A) VBAT (V) Time(minutes) Balancing in Charging Vbot Vtop Ibot Itop Ichar charge 2 18650 in series
www.eta-semi.com 6 Empower, Transcend, Achieve! ETA3001 Rev 1.2 TYPICAL PERFORMANCE CHARACTERISTICS Cont’d (TA=25C, unless otherwise specified) VBOT plug-in Start-Up , VTOP = Floating , RS = 50mΩ, VBOT = 4.3V VTOP plug-in Start-Up , VBOT = Floating , RS = 50mΩ, VTOP = 4.3V VBOT plug-in Start-Up , VTOP = Shorted , RS = 50mΩ, VBOT = 4.3V VTOP plug-in Start-Up , VBOT = Shorted , RS = 50mΩ, VTOP = 4.3V VTOP plug-out, DOWN Condition, RS = 50mΩ, VTOP = 4.3V, VBOT = 3.5V VBOT plug-out, DOWN Condition, RS = 50mΩ, VTOP = 4.3V, VBOT = 3.5V SW BATP BATC ISW SW BATP BATC ISW
www.eta-semi.com 7 Empower, Transcend, Achieve! ETA3001 Rev 1.2 TYPICAL PERFORMANCE CHARACTERISTICS Cont’d (TA=25C, unless otherwise specified) VTOP plug-out, UP Condition, RS = 50mΩ, VBOT = 4.3V, VTOP = 3.5V VBOT plug-out, UP Condition, RS = 50mΩ, VBOT = 4.3V, VTOP = 3.5V FEATURE DESCRIPTION The ETA3001 is a battery cell balancer with lossless inductive architecture based on ETA ’s proprietary technology. The technology is developed by ETA Solutions and any copy without ETA‘s agreement will be forbidden. During operation, ETA3001 detects the difference between 2 cells then start balancing if the difference exceeds VKICK. Once detected VKICK, ETA3001 will discharge the higher voltage cell, store that discharging energy in the inductor then charge that energy to the lower voltage cell. ETA3001 keeps balancing until there is no difference between 2 cells. ETA3001 technology allows balancing in either charge or discharge phases of t he battery with minimized loss.Without unbalanced condition, ETA3001 operates in sleep mode with low supply current. This is an advantage to extend battery pack life time. STATE MACHINE The ETA3001 provides a completed state machine that controls whole operation intelligently. With this state machine, ETA3001 is equipped with self- protection from any accident during balancing. It also keeps the part stay asleep as much as possible until unbalance detected. ETA3001 always starts from CHECK state when battery is plugged in. Any fault always forces ETA3001 back to SLEEP State where ETA3001 burns only 2µA (typically) from BATP. Figure 3: State Machine Diagram SLEEP STATE CHECK STATE BALANCE STATE TSLEEP Expired TCHECK Expired TALLOW Expired and Unbalance Detected TSD or OVP Skipping and TDONE Expired VBATP < UVLOAny State SW BATP BATC ISW SW BATP BATC ISW
www.eta-semi.com 9 Empower, Transcend, Achieve! ETA3001 Rev 1.2
APPLICATION INFORMATION
Balancing current is defined as the average inductance current. Average inductance current is regulated following ISET resistor configuration. AVERAGE INDUCTION CURRENT RECOMMENDED COMPONENT ISET RESSITOR ISET CAPACITOR INDUCTOR BATTERY CAPACITOR 500mA 100mΩ 0pF – 10nF 0.47-1µH 4.7µF – 10µF 625mA 80mΩ 0pF – 10nF 0.68-1µH 4.7µF – 10µF 800mA 62.5mΩ 0pF – 10nF 0.68-1µH 4.7µF – 10µF 1000mA 50mΩ 0pF – 10nF 0.68-1µH 4.7µF – 10µF 1250mA 40mΩ 0pF – 10nF 0.68-1µH 10µF 1515mA 33mΩ 0pF – 10nF 0.68-1µH 10µF 1667mA 30mΩ 0pF – 10nF 1µH 10µF 2000mA 25mΩ 0pF – 10nF 1µH 10µF RESTRICTED CONDITIONS ETA3001 does not allow following restricted conditions: ➢ Reverse battery connection ➢ Short SW to any of BATN, BATP , BATC ➢ Exceed the absolute maximum rating of each IC pin MOSFETs SELECTION External N-type MOSFETs must meet the condition of VDS>12V. The value of Qg should range from 1nC to 3nC, which can make the MOSFETs respond faster. MULTI-CELLS BALANCING SOLUTION It is also possible to use several ETA3001 ICs in application to balance multi -cell series battery, such as shown in the Figure 6 (n cells). For example, Figure 6 shows a typical solution for 4-cell-battery in laptop battery pack. Each ETA3001 manages balancing of 2 neighbor cells. Each ETA3001 operates independently.
www.eta-semi.com 10 Empower, Transcend, Achieve! ETA3001 Rev 1.2 ETA3001 BATP HGATE BIAS SW LGATE BATN BATC ISET 10uF 10uF 1uH 10nF optional 10uF 100Ω Rs Cell 1 Li Battery ETA3001 BATP HGATE BIAS SW LGATE BATN BATC ISET 10uF 1uH 10nF optional 10uF 100Ω Rs Cell 2 ETA3001 BATP HGATE BIAS SW LGATE BATN BATC ISET 10uF 1uH 10nF optional 10uF 100Ω Rs Cell 3 Cell n TVS TVS TVS TVS Figure 6: Multi -Cell Balancing Solution
www.eta-semi.com 11 Empower, Transcend, Achieve! ETA3001 Rev 1.2 PCB DESIGN GUIDELINE In an UP case that bottom cell voltage is greater than top cell voltage, bottom cell becomes input and top cell becomes output of the switching regulation. In a DOWN case that top cell voltage is greater than bottom cell voltage, top cell becomes input and bottom cell becomes output. These mean parallel battery capacitors are always output capacitor or input capacitor for regulator. So please require to locate as close as possible to IC pins to minimize series resistance. Please try to get the order of battery pins are BATP – BATC – BATN to make an easy battery connection. BATP HGATE SW LGATE BATC ISET BIAS BATN ETA3001 GND 10nF Rs 1uH 100Ω 10uF BATP BATCBATN Via Top Layer Bottom Layer D G S D G S 10uF 1uF
www.eta-semi.com 12 Empower, Transcend, Achieve! ETA3001 Rev 1.2 PACKAGE OUTLINE Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 0.700 0.800 0.028 0.031 A1 0.000 0.050 0.000 0.002 A3 0.203 REF 0.008 REF D 1.924 2.076 0.076 0.082 E 1.924 2.076 0.076 0.082 D1 1.100 1.300 0.043 0.051 E1 0.500 0.700 0.020 0.028 k 0.200 MIN 0.008 MIN b 0.200 0.300 0.008 0.012 e 0.500 TYP 0.020 TYP L 0.274 0.426 0.011 0.017
www.eta-semi.com 13 Empower, Transcend, Achieve! ETA3001 Rev 1.2 TAPE AND REEL INFORMATION Device Package Type Pins SPQ Reel Diameter (mm) Reel Width W1 (mm) (mm) (mm) (mm) P (mm) W (mm) Pin1 Quadrant ETA3001D2I DFN2x2-8 8 3000 180 9.5 2.3 2.3 1.1 4 8 Q1