#Lithium ion battery charger portable

Connecting the TIMER pin to the input supply disables internal termination, allowing the charger to be manually shut down through the enable, EN, input. Grounding the TIMER pin and connecting a resistor to the IDET pin causes the charge cycle to terminate once the charge current falls below a programmed threshold (I DETECT). Connecting an external capacitor to the TIMER pin activates an internal timer that stops the charger after the programmed time period has elapsed. The TIMER pin controls which method of termination the LTC4061 and LTC4062 uses. When using total time termination, the charge time is set by connecting a capacitor, C TIMER, from TIMER to ground. Alternatively, this threshold can be used as the termination current threshold completing the charge cycle.

This threshold is used to change the state of the CHRG pin indicating that a battery is nearly full. The charge current out of the BAT pin can be determined at any time by monitoring the PROG pin voltage and applying the following equation:ДЄ current detection threshold, I DETECT, is set by connecting a resistor, R DETECT, from IDET to ground.

The maximum charge current is programmed using a single resistor from the PROG pin to ground. The LTC4061 and LTC4062 provide a great deal of design flexibility including programmable charge current and programmable total time termination or programmable current termination. Internal thermal feedback regulates the charge current to maintain a constant die temperature during high power operation or high ambient temperature conditions.

With input power applied, LTC4061 and LTC4062 can be put into shutdown mode to reduce the supply current to a very low value (20в™љ) and the battery drain current to less than 2в™љ. Without input power applied, the LTC4062 internal low power comparator can function while drawing just 10в™љ from the battery. In the LTC4062, a low I q precision comparator replaces the NTC and ACPR functions of the LTC4061. Additional safety features designed to maximize battery lifetime and reliability include Negative Temperature Coefficient, NTC, battery temperature sensing (LTC4061) and the SmartStart в„ў charging algorithm, which extends the lifetime of the battery by preventing unnecessary charge cycles. The LTC4061 provides an AC Power open-drain status pin, ACPR, to indicate that enough voltage is present at the input to charge a battery. The open-drain charge status pin, CHRG, can be programmed to indicate the state of the battery charge according to the needs of the application. The LTC4061 and LTC4062 include both programmable time and programmable current based charge termination schemes. They include an internal P-channel power MOSFET and thermal regulation circuitry with no blocking diode or external sense resistor required-the basic charger circuit requires only two external components. The LTC4061 and LTC4062 are specifically designed to charge single-cell lithium-ion batteries from either of these sources.Д«oth devices use constant current/constant voltage algorithms to deliver up to 1A of charge current (programmable) with a final float voltage accuracy of вђ.35%. A wall adapter is the most common source of charging power, but an increasing number of applications are tapping into available USB power.

#Lithium ion battery charger portable

Rechargeable batteries are commonly used to power portable devices such as digital cameras, PDAs, mobile phones and MP3 players. New Standalone Linear Li-Ion Battery Chargers