CST5080F is a dual series battery balanced charging management chip, built-in maximum 1A linear charging and series parallel switching circuit, can achieve balanced charging for 2 series batteries.

    CST5080F has a complete trickle charging (TC), constant current (CC) and constant voltage (CV) charging three charging processes; Trickle charge (TC) stage can be pre-charged to restore the fully discharged battery; Safe step-down fast charging under constant current (CC) mode; The final stage Constant voltage (CV) charging mode ensures that the full battery capacity is safely reached.

    CST5080F integrated series and switching MOS, single-channel switching MOS conduction resistance of 150 mΩ, can switch two-series battery into a single battery charging; The control timing of switching MOS is realized by hardware, and the switching reliability is high.

    CST5080F supports two series battery differential pressure detection. If the voltage differential pressure of two batteries is greater than 30mV, the low-voltage battery will be charged first to ensure the balance of two-series battery charging.

    The CST5080F supports one LED charging status indicator and two battery status indicator pins. When switching to the corresponding battery, B1_SAT and B0_SAT will correspond to the output high level to indicate the currently connected battery;

    CST5080F has input undervoltage protection, which can intelligently adjust the charging current and adapt the load capacity of the adapter to prevent the adapter from being hung up.

    CST5080F available in eSOP8 package.

    Full voltage: 4.2V, support custom full voltage range: 4.05V-4.4V (step=50mV)

    Charging current 500mA, support customized charging current range: 20MA-1A (step=20mA).

    Support custom lithium iron phosphate battery, full voltage range: 3.5V-3.8V (step=50mV)

    ESD 4KV

    Supports a variety of protection functions: IC overtemperature protection, input undervoltage protection, input overvoltage protection

    Support LED charging status indicator function, support constant current function (can omit LED current limiting resistance)

    Low standby power consumption, battery BAT power consumption is less than 3uA

    Switching timing hardware implementation, high reliability

    Switching MOS withstand voltage greater than 10V, support negative pressure resistance

    Two status indicator output pins

    Support two-string battery differential pressure detection to achieve balanced charging

    Built-in switching MOS, single channel internal resistance 150mΩ

    Trickle current is 1/5 of constant current

    The full stop-charge detection current is 50mA

    Two-string lithium battery charging application

CST5080F pin schematic and pin description: 

CST5080F Limit parameters:

    * Stresses above the values listed in the absolute maximum rating section may cause permanent damage to the device, and prolonged exposure under any absolute maximum rating condition may affect the reliability and service life of the device

CST5080F Recommended working conditions:

    * CST5080F operating characteristics are not guaranteed beyond these operating conditions.

CST5080F Electrical characteristics: (unless otherwise specified, TA=25℃, VIN=5V)

CST5080F internal block diagram:

CST5080F Charging process:
    The CST5080F features a full trickle/constant current/constant voltage charging mode.
    When the battery voltage is less than the trickle constant current voltage VTK, the trickle charging current ITK is used to charge the battery.
    When the battery voltage is greater than VTK, the constant current charging current ICC charges;
    When the battery voltage is close to the set constant voltage charging voltage VCV, the charging voltage VCV remains unchanged, the charging current slowly decreases, and the battery enters the constant voltage charging mode.
    After entering the constant voltage charging mode, if the charging current is less than the full stop charge detection current ISTOP, the charging will be stopped first, and then the battery voltage will be detected whether it is higher than the stop charge voltage VSV; If it is higher than the stop charging voltage VSV, stop charging; If it is below the stop charge voltage, continue charging.
    After the battery is full and stops charging, and the input VIN remains valid, if the battery voltage is less than VRC, it will enter the full and recharge stage, and the charging process will be started again.

CST5080F Charging Protection:
    CST5080F has perfect protection function, integrated input undervoltage, input overvoltage, IC overtemperature protection and other functions to ensure stable and reliable system work.
    The CST5080F features VIN input undervoltage protection, which automatically adjusts the charging current to reduce when the input voltage is detected to be close to 4.5V, ensuring that the adapter does not pull.
    The CST5080F integrates overtemperature protection to force charging to stop when the internal temperature of the chip is detected to exceed 140 degrees.

CST5080F Charging LED Instructions:
    CST5080F lights display: LED blinks during charging (1S on, 1S off), LED is on after full charging. Abnormal state (overtemperature protection) LED blinking (on for 0.5S, off for 0.5S).
    LED output is current limiting mode, current limiting 3mA when the light is on, support LED lights without current limiting resistance; When the indicator is off, it is in the high resistance state.
    The CST5080F-DA-1A can tap two lights on one pin, and the indicator is: LED_R is on and LED_G is off during charging. When the battery is fully charged, the LED_R is off and the LED_G is on. In the abnormal state (overtemperature protection), the LED_R and LED_G blink alternately (on for 0.5S and off for 0.5S).

CST5080F Battery Switching Strategy:
    CST5080F can realize the differential pressure detection function of two batteries, and realize the balanced charging of two batteries.
    When the voltage pressure difference between the two batteries is greater than the pressure difference threshold VTH, CST5080F will consider the voltage imbalance between the two batteries, and will give priority to charging the battery with low battery voltage, and stop charging 1ms after charging for 1s to detect the battery voltage until the pressure difference between the two batteries is less than the pressure difference threshold VTH.
    When VBAT1-VBAT0>VTH, it is STA1 state, CST5080F prefertively charges BAT0, internal MOS Q1 and Q3 are off, Q2 and Q4 are on, B1_SAT pin will be set to high, the rest are low.
    When VBAT0-VBAT1>VTH, it is STA3 state, CST5080F prefertively charges BAT1, internal MOS Q2 and Q4 are off, Q1 and Q3 are on, B1_SAT pin will be set to high, the rest are low.
    When the voltage difference between the two batteries is less than the pressure difference threshold VTH, it is STA2 state, CST5080F will consider that the voltage of the two batteries is balanced, and will switch to the balanced charge of the two batteries in turn, charge one battery for 1s, then stop 1ms to detect the battery voltage, and then charge the other battery, and continue to cycle.
    CST5080F sets both B1_SAT and B1_SAT to high when detecting differential pressure between two batteries.

CST5080F Actual battery charging curve:
    Charge two series batteries with the CST5080F, and charge two series actual batteries with different initial voltages with 500mA charging current at IN=5V. The initial voltage of the two batteries is 3.2V and 3.7V respectively, and the voltage of the two batteries after full is.2V.

    Charge two series batteries with the CST5080F 1A, and charge two series actual batteries with different initial voltages at VIN=5V with 1A charging current. The initial voltage of the two batteries is 3.2V and 3.7V respectively, and the voltage of the two batteries after full is.2V.

CST5080F Typical application schematic diagram:

CST5080F BOM:

CST5080F Package Information: