Микроконтроллеры AVR

Внимательнее!  EXTERNAL VOLTAGE REFERENCE The ADS1242 and ADS1243 require an external voltage reference. The selection for the voltage reference value is made through the ACR register. The external voltage reference is differential and is repre- sented by the voltage difference between the pins: +VREF and –VREF. The absolute voltage on either pin, +VREF or –VREF, can range from GND to VDD. However, the following limitations apply: For VDD = 5.0V and RANGE = 0 in the ACR, the differential VREF must not exceed 2.5V. For VDD = 5.0V and RANGE = 1 in the ACR, the differential VREF must not exceed 5V. For VDD = 3.0V and RANGE = 0 in the ACR, the differential VREF must not exceed 1.25V. For VDD = 3.0V and RANGE = 1 in the ACR, the differential VREF must not exceed 2.5V.