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SL1053

Constant Voltage Regulation and Charge

Termination Mode

When the battery voltage reaches the regulation voltage VO(REG), the constant voltage feedback

control starts, and then the charge current begins to decrease as the typical charge profile shown.

As the charge current decreases to lower than charge terminated current threshold, the SL1053

will terminate the charge cycle.

Recharge Mode

After the charge termination mode, if the battery voltage falls to lower than the recharge threshold

voltage VO(RCH), the SL1053 will begin a new charge cycle according to the battery voltage.

Battery Temperature Detection

The SL1053 continuously detects the battery temperature by measuring the TS pin voltage. A

NTC or PTC thermistor can parallel with RT2 to deviate the TS pin voltage. (As shown in Figure

5) The TS pin voltage must be within normal temperature voltage range that is shown in Figure 6

and electrical characteristics, and then SL1053 can start working normally.

The RT1 and RT2 can be derived from following equations.

For NTC Thermistors:

Where RTL is the resistance value in lowest desired operation temperature and RTH is the

resistance value in highest desired operation temperature. The resistances of thermistors are

specified by the thermistor manufacturer. If the temperature monitoring function is not desired,

there's an easy method to set RT1 and RT2 at the same value and disconnect the thermistor to

disable this function.