LTC4123 operaTion UNIT POWERED YES BATTERY IN REVERSE *BAT < –50mV? STOP CHARGING *REVERSE BATTERY CONDITION IS PULSE LED FAST CHECKED THROUGHOUT THE ALGORITHM NO **IF THE DIE TEMPERATURE IS TOO HIGH START CHARGE TIMER OR TOO LOW DURING ZINC-AIR BATTERY START CHARGING DETECTION (80 SECONDS), THIS 80 SECOND PULSE LED SLOWLY TIMER WILL BE RESET YES ZINC-AIR BATTERY PRESENT BAT > 1.65V? STOP CHARGING PULSE LED FAST NO NO TIME = 80sec? YES NiMH PRESENT CONTINUE CHARGING PULSE LED SLOWLY **DIE TEMPERATURE YES STOP CHARGING TOO HIGH OR PAUSE CHARGE TIMER TOO LOW? PULSE LED FAST NO NO CHARGE TIMER YES CHARGING COMPLETE EXPIRED? STOP CHARGING LED ON 4123 F02 ALL THE VALUES LISTED ABOVE ARE TYPICAL. SEE ELECTRICAL CHARACTERISTICS TABLE FOR MORE INFORMATION Figure 2. Charge Algorithm 4123fa For more information www.linear.com/LTC4123 9