Functional Description

Normal state

Time (TODR).

Overcurrent status

Over discharge state

CW1073

Temperature protection function

The DO_PWM terminal outputs a low level to turn off the discharge MOSFET and stop discharging. Over-discharge protection

release conditions: VM terminal voltage is

lower than 2V (load release), all battery voltages are higher than the over-discharge release voltage (VODR) and maintain for more than the over-discharge release delay time.

The terminal outputs a high impedance state to turn off the charging MOSFET and stop charging.

Under normal conditions, if the voltage of any battery cell is higher than the overcharge detection voltage (VOC) and exceeds the overcharge protection delay time (TOC), CO

CW1073 has three levels of built-in overcurrent detection, overcurrent 1, overcurrent 2 and short circuit protection.

Protection mechanism: The voltage of the current sampling resistor on the main circuit is detected through the CS terminal to determine whether CW1073 enters the corresponding overcurrent protection state.

Taking

overcurrent 1 protection as an example, the discharge current changes with the external load. If the CS terminal detects that the voltage on the current sampling resistor is higher than the overcurrent 1 protection

threshold (VEC1) and maintains more than the overcurrent 1 protection delay time (TEC1), the DO terminal and DO_PWM terminal output low level to turn off the discharge MOSFET and stop discharging. Overcurrent

protection release condition: The VM terminal

voltage is lower than 2V (load release) and

exceeds the overcurrent release delay time (TECR), and the overcurrent protection is released.

(TRESET), the accumulated overcharge delay time (TOC) is reset. Otherwise, the drop in battery voltage is considered as irrelevant interference and is shielded.

After the charging temperature protection, the charging MOSFET is turned off and charging stops; After

the discharging temperature protection, the discharging MOSFET is turned off and discharging stops;

Charging temperature protection release

condition: The temperature returns to within the charging release temperature, and the time exceeds the charging temperature release delay, the charging temperature

protection is released. Discharging temperature

protection release condition: 1. The chip has a temperature protection recovery load lock function: The VM terminal voltage is lower than 2V (load release), the temperature returns to within the discharge release

temperature, and the time exceeds the discharge temperature release delay, the discharge temperature protection is

released. 2. The chip does not have a temperature protection recovery load lock function: The temperature returns to within the discharge release temperature, and the time exceeds the discharge temperature release delay.

During the overcharge protection delay time (TOC), if the detected battery voltage is lower than the overcharge detection voltage (VOC) for a period longer than the overcharge reset delay time

CW1073 uses an NTC resistor to achieve charge and discharge over-temperature protection and charge and discharge low-temperature protection functions. The ROT and RUT terminals detect the

NTC resistor voltage. If the detection voltage reaches the internal comparison threshold and maintains the charge and discharge temperature protection delay time, the temperature protection function is triggered.

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Under normal conditions, if the voltage of any battery is lower than the over-discharge protection voltage (VOD) and exceeds the over-discharge protection delay time (TOD), the DO terminal

Overcharge protection release condition:

All battery voltages are lower than the overcharge release voltage (VOCR) and exceed the overcharge release delay time (TOCR).

When the discharge temperature protection is

released. Over-temperature threshold

setting steps 1. Select the NTC resistor. The recommended NTC resistor model for CW1073 is: 103AT, B=3435;

11

When the terminal voltage is lower than the overcurrent detection voltage (VEC1), CW1073 is in normal working state. Overcharge state

All battery voltages are between the overcharge detection voltage (VOC) and the overdischarge detection voltage (VOD), the battery temperature is within the operating range, and CS