LTC4123 operaTion charge resistance of a Zinc-Air battery is higher than a Table 1. CHRG Pin Status Summary NiMH battery and therefore the battery voltage of Zinc-Air CHRGBlink FrequencyCharge Status rises significantly. An LED connected to CHRG will blink On (Pull-Down) Charging complete fast indicating a battery fault condition. Blink Slow (0.8Hz) Charging If the LTC4123 is in UVCL mode at the beginning of the Blink Fast (6Hz) Fault-No Charging; Temperature Fault/ charge cycle (typically 3 seconds after power is first ap- Battery in Reverse/Zinc-Air Battery Present/UVCL at the beginning of plied), it is unable to provide full charge current to perform charge cycle Zinc-Air battery detection. In this case, a battery fault will Off (High Impedance) No power/No Charging be indicated at CHRG (blink fast). Adjust the magnetic coupling between the receive and transmit coils to restart Operation without Wireless Power the charging cycle. LTC4123 can be powered by connecting a DC voltage When a battery is inserted in reverse or the die temperature source to the VCC pin instead of receiving power wirelessly is above 70˚C or below –5˚C, an LED connected to CHRG through the ACIN pin. Ground the ACIN pin if an input will blink fast. Table 1 summarizes the four different pos- supply voltage is connected to VCC. sible states of the CHRG pin when the charger is active. 4123fa 10 For more information www.linear.com/LTC4123