> 3.16 | Analog-to-Digital Converter (ADC)

> The ADC of the TC65 consists of 2 independent, unbalanced, multiplexed analog inputs that can be used for measuring external DC voltages in the range of 0mV…+2400 mV. The ADC has a resolution of 12 bits.
> Use the command AT^SRADC described in [1] to select the analog inputs ADC1_IN or ADC2_IN, to set the measurement mode and read out the measurement results. The measured values are indicated in mV with a resolution of 1mV.
> There is no out of range detection. Voltages beyond these limits cannot be measured:

> • | Underflow: Values = -25 mV

> • | Overflow: Values > 2425 mV

> The sample period is adjustable from 30 s up to 100 ms by AT^SRADC
> Only during sample time (ts~400 µs) the S&H Switch is closed.
> Figure 35: Analog-to-Digital Converter (ADC)
> Restrictions during SLEEP Mode
> During SLEEP mode the ADC is shut down temporarily (by default). Please make sure that during SLEEP mode shutdown the ADCx_IN input voltage does not exceed ±0.3 V. The input current (reverse feeding) may reach 3 mA. If SLEEP mode is activated there are three protection possibilities:

> 1. | Use the RC combination as shown in Figure 35 for current limitation. Advantages: Lowest current consumption at SLEEP mode, small component count, high input resistance Disadvantages: Lower input resistance at SLEEP mode (100 k only).

> 2. | Use the AT^SNFM=,1 command to enable the ADC supply continuously. Advantages: No additional component components needed. Disadvantages: Higher current consumption in SLEEP mode (about 2 mA).

> 3. | Detect presence of VMIC-voltage. If VMIC is off, make sure that ADCx_IN input voltage does not exceed ±0.3 V Advantages: Lowest current, high input resistance. Disadvantages: Effort for SLEEP mode (VMIC) detection.