This TPS62240 has an efficiency of 95% across any load above 1mA. Below 0.1mA, its 15uA quiescent current kills its efficiency... but it still has over 70% efficiency at 0.1mA. That is, the converter uses say... 0.13mA while outputting only 0.1mA. (I mean, it really should be in terms of Watts. But since P = VxI, the mA estimation is a good enough indicator).
So in effect, a SINGLE AA NiMH batteries can run at 0.13mA for around 2 years. In practice, the self-leakage of these batteries are the major problem on those time periods.
At some point, reducing quiescent power consumption isn't a major problem anymore. I think the ridiculously efficient 500pA draw is unlikely to be used in any design where a AA battery is sufficient.
Smaller coin-batteries have issues ramping up to the ~50mA to transmit a radio signal. So I'd bet that in practice, AA batteries (or larger 18650 cells) will continue to be used... and therefore a hugely power-efficient design from these researchers won't have a major competitive edge.
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As an FYI: These efficient power converters enter "sleep" modes while the voltage output is above 1% of the voltage. Once the voltage drops to the nominal voltage, the TPS62240 "wakes up" and starts injecting charge into the capacitor / inductors... before entering another sleep cycle.
Furthermore, at higher currents, I have my doubts that a charge-pump design would be superior to the capacitor/inductor design of a typical buck (or boost) converter. So sure... this charge-pump design might be more efficient at 0.1mA, but I bet you that the capacitor/inductor is more efficient at 50mA. (The TPS62240 hitting 95% efficiency in the >1mA range)
> new power converter that maintains its efficiency at currents ranging from 500 picoamps to 1 milliamp
Hmmm... so this design really is designed for below 1mA currents. I really wonder what applications they are trying to use. Below 1mA, I say... just be wasteful. If it takes two months for a AA battery to run out of charge... is there really an issue?
This TPS62240 has an efficiency of 95% across any load above 1mA. Below 0.1mA, its 15uA quiescent current kills its efficiency... but it still has over 70% efficiency at 0.1mA. That is, the converter uses say... 0.13mA while outputting only 0.1mA. (I mean, it really should be in terms of Watts. But since P = VxI, the mA estimation is a good enough indicator).
A single NiMH AA battery has 2000mAh of energy storage capacity, Eneloops actually are closer 2500mAh. https://www.amazon.com/Panasonic-BK-3HCCA4BA-Eneloop-Pre-Cha...
So in effect, a SINGLE AA NiMH batteries can run at 0.13mA for around 2 years. In practice, the self-leakage of these batteries are the major problem on those time periods.
At some point, reducing quiescent power consumption isn't a major problem anymore. I think the ridiculously efficient 500pA draw is unlikely to be used in any design where a AA battery is sufficient.
Smaller coin-batteries have issues ramping up to the ~50mA to transmit a radio signal. So I'd bet that in practice, AA batteries (or larger 18650 cells) will continue to be used... and therefore a hugely power-efficient design from these researchers won't have a major competitive edge.
-------
As an FYI: These efficient power converters enter "sleep" modes while the voltage output is above 1% of the voltage. Once the voltage drops to the nominal voltage, the TPS62240 "wakes up" and starts injecting charge into the capacitor / inductors... before entering another sleep cycle.
Furthermore, at higher currents, I have my doubts that a charge-pump design would be superior to the capacitor/inductor design of a typical buck (or boost) converter. So sure... this charge-pump design might be more efficient at 0.1mA, but I bet you that the capacitor/inductor is more efficient at 50mA. (The TPS62240 hitting 95% efficiency in the >1mA range)
> new power converter that maintains its efficiency at currents ranging from 500 picoamps to 1 milliamp
Hmmm... so this design really is designed for below 1mA currents. I really wonder what applications they are trying to use. Below 1mA, I say... just be wasteful. If it takes two months for a AA battery to run out of charge... is there really an issue?