Microcontroller with the fastest startup

Hi Jonathan,

Let me do a little research and I will get back to you.

Hi Dennis,

Thank you for your response.

I'm looking forward to hearing for the update.

Thanks a lot!

Jonathan

Hi Jonathan,

The MSP430 family of MCUs (G, F, FR) have typical clock startups in the order of a few micro-seconds (assuming the internal DCO is used).

Do you know if the customer is asking for start up time from a power on reset or wake from one of the low power modes?

There is a vast number of MSP430s to choose from so do you know what size, how many pins, how much memory, etc.?

Hi Dennis,

Thanks for looking into this. I am the customer Jonathan mentioned. 

The MSP430 family of MCUs (G, F, FR) have typical clock startups in the order of a few microseconds (assuming the internal DCO is used).

I found out yesterday that micro-seconds is possible with the other microcontroller, so i would like to see what your fastest startup time to ADC read is so i can compare. 

Do you know if the customer is asking for start-up time from a power-on reset or wake from one of the low power modes?

Not a low power mode. The system will be completely off. 

There is a vast number of MSP430s to choose from so do you know what size, how many pins, how much memory, etc.?

Hi James,

I found the MSP430G2453 comes close to your specifications.  It has an 8-channel 10bit ADC (SAR) with 0.5K RAM and 8K of FLASH, one I2C (USCI_B) and one SPI (USCI_A).  It is $0.80 in 1ku.  For details about the CPU and peripherals you will want to refer to the family user's guide.  Since you are interested in the ADC, refer to section 22.1.  It appears this can operate at 200ksps (which is typical for the 10bit converters in the MSP430 devices in this range) and the conversion clock can be sourced by several of the different system clocks.  Refer to page 39 in the datasheet for ADC timing and section 22.2.5 in the family users guide for sample and hold and conversion clock description.

Not sure how many samples you need to perform, but to setup and run one sample with the shortest sample and hold period (4 ADC10CLK) + conversion clocks (13 ADC10CLK), you are looking at 17 ADC10CLK periods.  The max freq for the ADC10CLK is 6.3MHz, so 17 clock periods would be 2.7usec, if my math is correct.

You also need to add in 100ns for the adc turn on time and a whopping 30usec for the ADC internal reference, if you use it and not the VCC. So lets say worst case you are using the internal reference instead of VCC. That puts you at >30usec just for the first ADC measurement after POR and this is just the ADC.

After POR you have system clock, boot code, code to setup the ADC and time to respond to the ADC interrupt when data is available.  Not sure how long that will take, but the MCU can run at 16MHz.

So far does his meet your requirement?  If we are close, let me know and I can put together some code and run on this device to measure the actual time it would take.

Hi Dennis,

Sorry for the delay, my last message seems not to have been posted. 

Thanks for offering to do some further tests. The MSP430G2453 does looks like it could be a good option, but we are still evaluating other microcontrollers. Is it ok if i get back to you when we know which microcontrollers have made our shortlist?  If the  MSP430G2453  does make it, then further testing would be very helpful, but we don't want to take too much of your time until we know which ones we want to go forward with. 

Kind Regards,

James