Using an external multiplexer in the ADC interface

Steve Woelfle

Other Parts Discussed in Thread: TMS570LC4357

Document spnu515a section 22.2 shows capability of five bits (EXT_SEL[4:0]) to control external analog mutiplexer for AD inputs. I can only find pin defintions for two of these: EXT_SEL0 = W8 and EXT_SEL1 = V9. Where are the other three bits?

over 11 years ago

0 KARTHIKEYAN RAJAMANICKAM over 11 years ago

TI__Genius 11645 points

Steve,

I believe only those two pins are bonded out in the package.

I will re-confirm this in a short while.

0 KARTHIKEYAN RAJAMANICKAM over 11 years ago in reply to KARTHIKEYAN RAJAMANICKAM

TI__Genius 11645 points

Steve,

As I mentioned earlier, you can only use the 2 LSB and ignore using the others as they are not available in your device (As an IP that module can support but not supported by the device). I will check with our documentation team to see if we can make this a little more explicit.

There are few devices like TMS570LC4357 which offers you all the 5 pins on the I/O's.

Hope its clear now.

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Using an external multiplexer in the ADC interface