Users Manual
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Trickle charge: it is divided into 2 parts, trickle charge-A: charge current 90mA when the battery voltage is lower
than 2.8V; trickle charge-B: charge current 450mA when the battery voltage is between 2.8V~3.2V;
Constant current charging: When the battery voltage is between 3.2V and 4.2V, the constant current is charged,
the charging current is 1.44A when the adapter is charging, and the charging current is 450mA when charging the
USB;
Constant voltage charging: When the battery voltage reaches 4.2V, the constant voltage is charged, the charging
current is gradually decreased, the charging current is reduced to about 100mA, and the charging is cut off.
"(&11.#)
The SLM756 module has battery temperature detection and can be implemented by BAT_THERM (46PIN). This
requires the internal integration of a 10KΩ thermistor (negative temperature coefficient) inside the battery to
connect the thermistor to the BAT_THERM pin. During the charging process, the software reads the voltage of the
BAT_THERM pin to determine if the battery temperature is too high. If the temperature is too high or too low, the
battery will stop charging immediately to prevent battery damage.
5(.-+#/&
The SLM756 can support two SIM cards at the same time to achieve dual card dual standby. Support SIM card hot
swap, can automatically recognize 1.8V and 3.0V cards. The figure below shows the recommended interface circuit
for the SIM card. In order to protect the SIM card, it is recommended to use TVS devices for electrostatic protection.
The DATA signal requires a 15K resistor to pull up to the SIM power supply. The device of the peripheral circuit of the
SIM card should be close to the SIM card holder.
The reference circuit is as follows:
Figure 4.29: UIM card interface circuit
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