DSP Chip and Eval Board

[pragash]

I want a simple CPU/MCU with a couple of 16-bit ADC in it. other functions are not required. Any chip available?

if that chip has an eval board which i can test, it will be great.

 

[FvM]

Simple CPU/MCU with multiple 16-bit ADC sounds somehow self-contradictory. The title also refers to DSP which is not the same as standard processor. You should mention at least ADC sampling rate, simultaneous sampling ADC or just muxed input ADC? Which DSP capabilities are intended?

 

[KlausST]

Hi,

I agree with FvM

It also depends on:
* AC performance, DC performance (For good AC performance at low cost, look for audio DSPs)
* input voltage range
* supply voltage
* multiplexed inputs or simultaneous sampling
* single ended or differential inputs
* and what "a couple" means in number.
* processing power

Klaus

 

[pragash]

The required ADC sampling rate is 35ksps. we just need a single/couple of ADC. simultaneous sampling ADC is preferred.

I just need ADC + MCU/CPU. I don't need any other DSP functions. I know it can be just an MCU instead of a DSP.

I'm not demodulating audio so Audio DSP/MCU is not required.

the input voltage range is 10mV to 100mV. 16-bit ADC should be able to detect this with the appropriate Vref setting.

supply voltage is 5V.

simultaneous sampling ADC is preferred.

single-ended input is preferred.

a couple of ADC means two ADCs.

Does processing power mean ADC power consumption? I think as of now, we don't have specs for this. if an ADC meets all the above specs, we will be able to accept that chip regardless of power consumption.

 

[KlausST]

Hi,

processing power: how much calculations / commands need to be performed (per second).

In your headline the first word is "DSP". So we thought this is your most important requirement.

Standard MCUs rarely provide ADCs with 16 bit performance.
Thus I still recommend you to check on audio DSPs.

If standard MCU: I recommend a dual chip solution. MCU + ADC. SPI or I2S interface should work.

Nowadays the supply voltage is rather 3.3V. Thus 5V limits your count of hits.

Klaus

 

[FvM]

There are a few uC with 16 bit ADC, also more than 1. I have e.g. used ADI ADuC series for single chip designs with measurement accuracy. Most developers have however strong bias towards one or several processor cores, thus I don't attempt to make a probably failing suggestion. Better use search tools of major processor manufacturers or distributors.

--- Updated Oct 28, 2022 ---

You should also consider that 16 bit resolution + higher speed is most likely hard to achieve inside a digital chip. In so far I agree with the separate ADC suggestion.

 

[danadakk]

Two possibilities, same chip, one chip, ARM + 2 SARs + 1 DelSig + Vref + see below

First top example using the Delsig, it can do 48KSPS @ 16 bits, uses on chip T & H to
enforce simul sampling. Note its effective rate is 24 KSPS which means you would skip
/ ignore every other incoming sample (cycle to cycle basis) to get your target speed.
If your design needs cannot work missing every other incoming sample this would
not be adequate.

The bottom example, 2 SARs (onchip) is 12 bits, but one could use averaging of
samples to get to 16 bits as it can convert at, in this config, 666KSPS. The Start of
Conversion input to SAR you can hook to whatever you want to trigger the simul-
taneous sampling of the 2 SARs. Ap notes on averaging and ENOB improvement
attached.


This is overall whats on the chip, multiple copies in many cases, like 4 OpAmps,
4 DACs, lots of logic elements, the M3 ARM core.........

Regards, Dana.