AME2056 Datasheet, PDF (14/26 Pages) Analog Microelectronics – 1A Single Cell Li-ion

AME
AME2056
1A Single Cell Li-ion
Battery Linear Charger
Under Voltage Lockout (UVLO)
The AME2056 incorporates an under voltage lockout circuit to keep the device disabled when V_CC is below the UVLO
rising threshold voltage. Once the UVLO rising threshold voltage is reached, the device start-up begins. The device
operates until V_CC falls below the UVLO falling threshold voltage. The typical hysteresis in the UVLO comparator is
200mV.
Manual Shutdown
The AME2056 can be shutdown by removing RPROG or pull the CE pin to the low-level voltage. A new charge cycle
is restarted by reconnecting the program resistor or pulling the CE pin to high-level voltage.
Automatic Recharge
After the charge cycle is terminated, the AME2056 monitors the BAT pin voltage by a comparator with a 1.8ms filter
time (T_RECHARGE). When the BAT pin voltage drops below 4.1V, a charge cycle restarts. The function can keep the
battery near a fully charged condition.
Stability Considerations
In constant-current mode, the feedback loop includes the PROG pin. Because of the additional pole created by the
PROG pin capacitor and resistor. The equivalent capacitance on this pin must be kept to minimum for the maximum
allowed program resistor. The pole frequency created by the PROG pin should be kept above 100kHz. When the PROG
pin is loaded with a capacitor, CPROG, the following equation can be used to calculate the maximum resistance.
R_PROG
≤
2×π
1
×10⁵
× C_PROG
Generally, the average battery current may be of interest to the user rather than instantaneous current. A simple RC
filter can be used on the PROG pin to measure the average battery current as shown in Figure 1. A 10K resistor has been
added between the PROG pin and the filter capacitor to ensure stability.
PROG
AME2056
GND
10K
RPROG
CHARGE
CURRENT
MONITOR
CIRCUITRY
C_FILTER
Figure 1
14
Rev. B.01