LTC4054

The LTC4054 is designed as one kind of constant-current/constant-voltage charger controller.The PWM controller uses a synchronous,quasi-constant frequency, constant off-time architecture that will not generate audible noise even when using ceramic capacitors.Charging current is programmable with a sense resistor and programming resistor to ±4% typical accuracy.Charging current can be monitored as a voltage across the programming resistor.An external resistor divider and precision internal reference set the final float voltage.

The LTC4054 has some features such as:(1)programmable charge current up to 800mA;(2)No external MOSFET,sense resistor or blocking diode required;(3)complete linear charger in thinSOTTM package for single cell lithium-ion batteries;(4)constant-current/constant-voltage operation with thermal regulation to maximize charge rate without risk of overheating;(5)charges single cell Li-Ion batteries directly from USB port;(6)preset 4.2V charge voltage with ±1% accuracy;(7)charge current monitor output for gas gauging;(8)automatic recharge;(9)charge status output pin;(10)C/10 charge termination;(11)25mA supply current in shutdown;(12)2.9V trickle charge threshold.It can be used in cellular telephones,PDAs,portable instruments and battery Backup systems.

The absolute maximum ratings of the LTC4054 can be summarized as:(1)input supply voltage:-0.3 to 10V;(2)PROG:-0.3V to VCC+0.3V;(3)BAT:-0.3V to 7V;(4)BAT short-circuit duration:continuous;(5)BAT pin current:800mA;(6)operating ambient temperature range:40°C to 85°C;(7)operating junction temperature:125°C;(8)operating junction temperature:40°C to 125°C;(9)lead temperature:300°C.If you want to know more information such as the electrical characteristics about the LTC4054,please download the datasheet in www.seekic.com or www.chinaicmart.com .