Hi, Expert,
I have several questions about the Iq of BQ24040, since we want to design a low power system.
1. From the spec, Iq is 1uA, when Vin=0V. I am curious are terminals on ISET, ISET2, PRETERM, and TS disabled in this period, even Battery is still on VOUT?
From my understanding TS should always be enabled to monitor the temperature of Battery, whatever Vin is ON or OFF. So if it's always on, it will consume ~50uA from Vout, much bigger than the value on spec, am I right?
2. Iout(done) is 6uA, when VIN=6V, Vout>Vout(reg). I don't understand the condition of Vout>Vout(reg). In what scenario, will Vout>Vout(reg), Vout(reg) is the output setting of internal regulator, which is 4.2V for BQ24040 in typical, Vout is the actual voltage on Vout/Battery. If there's no such scenario, what's the meaning of this parameter?
3. “The CHG terminal is low (LED on) during the first charge cycle only and turns off once the termination threshold is reached." How could we know the system is still charging, when Vout falls under VRCH, and starts a recharge. Could I get the right CHG status, if I don't re-plug in the adapter to get a new charge cycle?
Thanks so much!
Best regards,
Frank Liu