PGA900: T ADC Offset

Part Number: PGA900

Hi all

I try to measure a single ended Temperature voltage with the T Gain input. The measurement works finde, bot there is a offset in the PGA Measurement of about 2000 bits.

My Configurations are following:

I am working with the PGA900EVM

AMUX_CTRL:

TEST_MUX_T_EN = 1 (Tgain to TADC)

TSEM_N = 0 (Single ended)

T_GAIN_SELECT:

T_GAIN = 11 (20x Amplification)

The input is configured as 16Bit.

If i measure my signal at the VINTP input with a DMM i measure 0.056V

Calculation: 0.056V * 20 = 1.12V
1.12V / 5V *65536 = 14680 Bits

If I debug my software and read out the TADC_DATA the value is: 16770

Can someone explayn where this offset can come from?

Thanks