QAre there any recommendations for applying VDD on AD7829 ?
AWe recommend the following when using our AD7829 ADC:
1)When powering down the AD7829, we recommend that you do bring VDD all the
way to 0V when powering down, before re-applying power (VDD) again.
2)CONVST can go high with VDD, the important thing to remember here is not to
exceed VDD, we have tried both with CONVST connected to a pull-down
resistor...(10K to gnd ) and with a pull-up resistor to VDD, both
configurations are acceptable. Please ensure that you do not have a glitch on
CONVST especially during power-up as this will try to power-up the part without
VDD fully settled and cause the part to lock-up. The only way out of this
situation is to power-down and power-back up again correctly.
Unfortunately the above points, especially the first are not sufficiently
highlighted in the datasheet.