Hi All (I am new to this forum),
I am trying to power a 3.3v circuit using a 24v battery efficiently. The circuit draws up to 100mA @ 3.3v when awake, and about 30uA @ 3.3v when in sleep mode. The ratio of sleep time to awake time is about even (1:1).
The challenge is to drop from 24v to 3.3v as efficiently as possible. Therefore, linear regulators (i.e. variable resistors) are not an option since in this case the input current is the same as the output current, and therefore 24v - 3.3v = 20.7v is waisted as heat, especially when the circuit is awake drawing 100mA.
The other option I was considering is to use a switcher (output current < input current). I tried multiple switchers but unfortunately, they all have a quiescent current of at least a few hundred uA (250uA minimum), which is not efficient enough since this current is drawn @ 24v, so not convenient for when the circuit is in sleep mode. These switchers do have an Enable Pin but unfortunately this pin switches the whole circuit off which is not an option.
Any suggestions on how to solve this problem for the sleep mode part ?
I am trying to power a 3.3v circuit using a 24v battery efficiently. The circuit draws up to 100mA @ 3.3v when awake, and about 30uA @ 3.3v when in sleep mode. The ratio of sleep time to awake time is about even (1:1).
The challenge is to drop from 24v to 3.3v as efficiently as possible. Therefore, linear regulators (i.e. variable resistors) are not an option since in this case the input current is the same as the output current, and therefore 24v - 3.3v = 20.7v is waisted as heat, especially when the circuit is awake drawing 100mA.
The other option I was considering is to use a switcher (output current < input current). I tried multiple switchers but unfortunately, they all have a quiescent current of at least a few hundred uA (250uA minimum), which is not efficient enough since this current is drawn @ 24v, so not convenient for when the circuit is in sleep mode. These switchers do have an Enable Pin but unfortunately this pin switches the whole circuit off which is not an option.
Any suggestions on how to solve this problem for the sleep mode part ?