MC34673 is a cost-effective fully integrated battery charger suitable for lithium-ion or lithium polymer batteries. This charger can withstand an input voltage of 28V, eliminating the need for input overvoltage protection circuits for handheld devices. A charging cycle includes three charging modes: trickle, constant current (CC), and constant voltage (CV).
Add an external resistor, and the constant current mode current can be set to 1.2A. The constant voltage is fixed at 4.2V. When the battery voltage is below the trickle mode threshold, the trickle mode current is pre-set to 20% of the constant current mode current. The end of charge (EOC) current threshold is preset at 10% of the constant current mode current to save board space and cost. When the internal temperature of the IC rises to a preset threshold, the reverse thermal protection function of the charging current will limit the charging current.
MC34673 has a 2.6V power on reset (POR) falling edge threshold, allowing it to work perfectly with current limiting power supplies. Three indicator pins (PPR, CHG, and FAST) can be easily connected to a microprocessor or LED. When the power supply is not connected or disabled, the charger consumes less than 1.0 µ A of battery current.
NXP's MC34673 is a 1.2 single cell lithium-ion battery/lithium polymer battery charging IC system. Features:
- No need for external MOSFETs, reverse blocking diodes, or current sensing resistors.
Ensure a maximum programmable constant current mode current of 1.2A
Voltage accuracy of ± 0.7% within the temperature range of -20 ° C to 70 ° C
The current accuracy is ± 6% within the temperature range of -40 ° C to 85 ° C
The maximum input voltage of the power supply is 28V, and the overvoltage protection threshold is 6.8V
The minimum input operating voltage is 2.6V
Fully discharged batteries use trickle charging
Charging current monitoring
Thermal protection for charging current reversal
Single cell battery
Lithium ion battery or lithium polymer battery charger
Parallel interface and input control
Output current: 1.2A
Output voltage: 4.2V
