The AFEx3902-Q1
provide an external reference input. Select the external reference option by configuring the
VOUT-GAIN-x field in the DAC-x-VOUT-CMP-CONFIG register appropriately. The external
reference can be between 1.8 V and VDD. Equation 3 shows DAC transfer function when the external reference is used.
Note: The external reference must be less than
VDD in both transient and steady-state conditions. Therefore, the external reference must
ramp up after VDD and ramp down before VDD.
Equation 3.
where:
- N is the resolution in bits, 10 bits for
AFE53902-Q1 or 8 bits for AFE43902-Q1.
- DAC_DATA is the decimal equivalent of the binary code that is loaded
to the DAC register.
- DAC_DATA ranges from 0 to 2N – 1.
- VREF is the external reference voltage.