ADS1258: ADS1258

Hi TI,

We have design based ADS1258IRTCR

We have problem of reading external ADC input  16 Ch Single ended or DIFF - all read are not correct close to ~0V

We succeed to read SYSRED Internal measurements  : REF - GAIN - TEMP - VCC - OFFSET

-----------------------------------------------------
0x98 0xFF 0xFF 0xDA
FFFFDA
Voltage : -0.0000197917 V
OFFSET : -19.791667 uV
-----------------------------------------------------
0x9D 0x31 0x3F 0xDA
313FDA
Voltage : 1.6810468750 V
REF : 4.104118 V 
-----------------------------------------------------
0x9B 0x4 0xF7 0xD2
4F7D2
Voltage : 0.1695760417 V
TEMP : 169.576042 mV PRIORITY 27
Internal Temperature is : 27.799344 °C
-----------------------------------------------------
0x9A 0x3B 0x8F 0x23
3B8F23
VCC : 4.963261 V
-----------------------------------------------------
0x9C 0x78 0xB 0xC7
780BC7
Voltage : 4.0975703125 V
Device Gain (V/V) : 1.000383 V 
-----------------------------------------------------

Schematic:

 3010.Sheet1.pdf

Registers Setting :

  SetRegisterValue(CONFIG0, SPIRST_LONG | MUXMOD_AUTO | BYPAS_INT | CLKENB_ENABLE | CHOP_DISABLE | STAT_ENABLE);
  SetRegisterValue(CONFIG1, IDLMOD_STANDBY | DLY2_on | DLY1_on | DLY0_on | SBCS_OFF | DRATE_0);
  SetRegisterValue(MUXSCH, 0x00);  // MULTIPLEXER FIXED-CHANNEL REGISTER
  SetRegisterValue(MUXDIF, 0x00);  // MULTIPLEXER DIFFERENTIAL INPUT SELECT REGISTER
  SetRegisterValue(MUXSG0, 0xFF);  // MULTIPLEXER SINGLE-ENDED INPUT SELECT REGISTER 0
  SetRegisterValue(MUXSG1, 0xFF);  // MULTIPLEXER SINGLE-ENDED INPUT SELECT REGISTER 1
  SetRegisterValue(SYSRED, 0x3D);  //  0x00 0x3D  /* 0  - 0 - REF - GAIN - TEMP - VCC - 0 - OFFSET */