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Current is much more useful in engineering, because it is more constant for this type of device than power. Power varies with supply voltage while current norm

Current is much more useful in engineering, because it is more constant for this type of device than power. Power varies with supply voltage while current normally does not. Other than doing temperature calculations, power is not a very useful metric. And for such calculations you would use a max power rather than average power metric. If you were optimizing a system for "power" use, it is much easier to work in units of energy than power anyway.

TMSZ 10y ago
Nope. There is chip looking like PMU on board with at least two output power rails. For VoCore 1 there were two MT3410L converters, one for 3.3V and one for 1.8V. With switching converter total power consumption should be close to SoC power consumption, not depending on input voltage. Also specification is pretty clear: 74mA wifi standby, 230mA wifi full speed, 5V input. Input voltage range: 3.6V ~ 6.0V.
- mattthebaker 10y ago
  It is a generalized statement. Very few SoCs have internal switch mode controllers. It is going to either be an LDO, or take a fixed operating voltage. Requirements for such will be specified in current, which is more useful than power. Module level specs would be irrelevant in engineering because there is little incentive to use something like this, the radio isn't even certified. On that note, get your popcorn ready for when they ship to German backers and customs proceeds to trash them.
  - TMSZ 10y ago
    > Very few SoCs have internal switch mode controllers. That's why PMUs are used. Just look at bottom side of the PCB - there are three coils, two of them very close to the chip looking pretty much like PMU. > It is going to either be an LDO, or take a fixed operating voltage. No, read specification: 3.6 - 6V.
programmer_dude 10y ago
> Current ... is more constant for this type of device than power. Power varies with supply voltage while current normally does not. Can you explain why?
- Dylan16807 10y ago
  The chip is designed to run at a certain minimum voltage, and does so at a certain current. Feeding more voltage does not change its general operation. It throws the excess away as heat and keeps drawing the same current. You can attach an external circuit to convert to the desired voltage and therefore keep power draw constant. But that takes more space and costs more money. Throwing away excess voltage as heat is simply easier.

TMSZ 10y ago

Nope. There is chip looking like PMU on board with at least two output power rails. For VoCore 1 there were two MT3410L converters, one for 3.3V and one for 1.8V. With switching converter total power consumption should be close to SoC power consumption, not depending on input voltage. Also specification is pretty clear: 74mA wifi standby, 230mA wifi full speed, 5V input. Input voltage range: 3.6V ~ 6.0V.

mattthebaker 10y ago
It is a generalized statement. Very few SoCs have internal switch mode controllers. It is going to either be an LDO, or take a fixed operating voltage. Requirements for such will be specified in current, which is more useful than power. Module level specs would be irrelevant in engineering because there is little incentive to use something like this, the radio isn't even certified. On that note, get your popcorn ready for when they ship to German backers and customs proceeds to trash them.
- TMSZ 10y ago
  > Very few SoCs have internal switch mode controllers. That's why PMUs are used. Just look at bottom side of the PCB - there are three coils, two of them very close to the chip looking pretty much like PMU. > It is going to either be an LDO, or take a fixed operating voltage. No, read specification: 3.6 - 6V.

programmer_dude 10y ago

> Current ... is more constant for this type of device than power. Power varies with supply voltage while current normally does not. Can you explain why?

Dylan16807 10y ago
The chip is designed to run at a certain minimum voltage, and does so at a certain current. Feeding more voltage does not change its general operation. It throws the excess away as heat and keeps drawing the same current. You can attach an external circuit to convert to the desired voltage and therefore keep power draw constant. But that takes more space and costs more money. Throwing away excess voltage as heat is simply easier.