After power-up, the internal registers must be
initialized to their default values through a hardware reset
by applying a high pulse on the RESET pin, as shown in Figure 9-6.
Apply AVDD and IOVDD (no specific sequence required). After AVDD is applied, the
internal bandgap reference powers up and settle
out in ~ 2 ms.
Configure REFBUF pin (pull high or low even if configured via SPI later on) and apply the sampling clock.
Apply hardware reset. After hardware reset is released, the default registers
are loaded from internal fuses and the internal power up capacitor calibration is
initiated. The calibration takes approximately 200000 clock cycles.
Begin programming using SPI interface.
Figure 9-6 Initialization of serial registers after power
up
Table 9-5 Power-up timing
MIN
TYP
MAX
UNIT
t1
Power-on delay: delay from power up and logic level of REFBUF pin to RESET rising
edge