Hi, my name is Sang Rae Lee worked for PANAXTOS of Korea.
Our company has produced EEG product.
We are preparing new product together with one university in Korea.
In recent, we received prototype schematics including TI's ADS1294 from co-work university.
Now, we are reviewing about this prototype schematics to develop mass production.
We have some questions after reviewing schematics.
So, we want to obtain schematic review from expert engineers experienced in this part.
1. Description of our prototype schematic
1) End-application : EEG system
2) Power supply
(1) Analog Power : bipolar(AVDD:2.5V, AVSS:-2.5V)
(2) Digital Power : DVDD(3.3V)
3) Input signal : single-ended or differential input
4) Voltage Reference inputs : internal reference voltage
2. Question
1) Connection of pin VREFP and VREFN : We connected VREFP to GND(0V) and VREFN to AVSS(-2.5V). Is this correct?
2) Connection of unused pins : "Connect unused pins(INxP,INxN,RLDIN,.....) to AVDD" is written in TI's datasheet. Must we follow this guide line?
3) Connection of other unused pins : We are not using WCT and respiration function of ADS1294. So these pins(WCT, RESP_MODP,...) related to this function are left floating status. Is this correct?
4) We have firmware running in prototype product including ADS1294. But we have to develop mass product using ADS1294R. It is no difference in H/W but ADS1294 and ADS1294R between each product. Is it possible to run same firmware in new product including ADS1294R?
Thank you.