Follow these guidelines for best
performance of the AFEx39xx:
- For voltage output, short the
OUTx and FBx pins.
- Connect AEN to VDD using a pullup
resistor in the ADC mode.
- The external reference must not exceed VDD, either during transient or
steady-state conditions.
- For the best Hi-Z output
performance when VDD is off, use a pullup resistor on the VREF/MODE pin to VDD.
In case the VDD remains floating during the off condition, place a 100-kΩ
resistor to AGND for proper detection of the VDD off condition.
- All the digital outputs are open drain; use external pullup resistors on these
pins.
- The interface protocol is detected at power on, and the device locks to the
protocol as long as VDD is on.
- When allocating the I2C addresses in the system in I2C
mode, consider the broadcast address as well.
- I2C timeout can be enabled for robustness.
- SPI mode is three-wire by default.
- Configure the NC/SDO pin as SDO
in the NVM for SPI readback capability.
- The SPI clock speed in readback mode is slower than that in write mode.
- The I2C controller can only
be used for specific external devices that comply with the specified register
format.
- The target I2C readback
functionality when the I2C controller is enabled (VREF/MODE is high).
Make the VREF/MODE pin low to enable read and write functionality on the
I2C target interface.