思旺SE9013代理

SE9013

Operation The SE9013 is a single cell NiMH battery charger using a constant-current/constant-voltage algorithm. It can deliver up to 500mA of charge current (using a good thermal PCB layout) with a final float voltage accuracy of ±1%. The SE9013 includes an internal P-channel power MOSFET and thermal regulation circuitry. No blocking diode or external current sense resistor is required; thus, the basic charger circuit requires only two external components. Furthermore, the SE9013 is capable of operating from a USB power source. Normal Charge Cycle A charge cycle begins when the voltage at the VCC pin rises above the UVLO threshold level and a 1% program resistor is connected from the PROG pin to ground or when a battery is connected to the charger output. When the BAT pin approaches the final float voltage (1.4~4.2V depending on the customer setup), the SE9013 enters constant-voltage mode and the charge current begins to decrease. When the charge current drops to 60% of the programmed value, the charge cycle ends. Programming Battery Charge Voltage The final voltage the battery is to be charged to is determined by the following eqution: Where VFB is typically at 1.20V. Programming Charge Current The charge current is programmed using a single resistor from the PROG pin to ground. The battery charge current is 1060 times the current out of the PROG pin. The program resistor and the Charge Completion A charging indicator is switched off when the charge current falls to 60% of the programmed value after the final float voltage is reached. This condition is detected by using an internal, filtered comparator to monitor the PROG pin. When the PROG pin voltage falls below 100mV for longer than tTERM (typically 1ms), charging indicator is switched off. The charge current remains until the battery voltage reaches the programmed value. When charging, transient loads on the BAT pin can cause the PROG pin to fall below 100mV for short periods of time before the DC charge current has dropped to 60% of the programmed value. The 1ms filter time (tTERM) on the termination comparator ensures that transient loads of this nature do not result in premature charge cycle completion. The SE9013 constantly a