MC9S08QB8 ADC current consumption temperature sensor

[admin]

Hello everybody,

I have got some questions about the ADC module and it´s current consumption of the MC9S08QB8. Table8 on page14 of the datasheet (rev3, 3/2009) says, that the "Run suppy current - FEI mode, all modules on" at 1MHz and 3V is typically about 0.8mA. I will not be able to run the MCU in any LowPower-Modes, because there a continuous calculations to do.

My questions now:

1) does "all modules on" include the ADC with it´s current consumption?

2) if not, do I have to add the ADC specific supply currents (page22) to the 0.8mA?

3) does every of the 8 ADC channel take current or are those characteristics for the whole ADC module?

4) does the TemperatureSensor take additional current or does it behave like a 'normal' channel?

Thanks in advance. Regards.

Benjamin

[Encoder1]

Hi Ben,

for my experience here is:

1. All modules obviously includes ADC. In case 3V/1MHz Is=0.8mA, presumably with ADC is in its lower power state.
2. No if not in high speed, short sample. I think 0.8mA total supply is "typical" i.e. minimum or intermediate state regarding ADC power sink
3. No. only one channel is active each time, the others are high impedance state
4. No. Temperature sensor bias is only few uA and this is included in the ADC supply.

Regards,

Salvatore