Hello everyone,

Need help, how interface 13-bit ADC MCP3304 with ATMEGA16/32 and if possible to use AREF 5.0V IC REF02 from ATMEGA16/32 my project board for VREF 5.0V MCP3304.

 

From datasheet:

Communication with the MCP3302/04 devices is done
using a standard SPI-compatible serial interface.
Initiating communication with either device is done by
bringing the CS line low (see Figure 6-2). If the device
was powered up with the CS pin low, it must be brought
high and back low to initiate communication. The first
clock received with CS low and DIN high will constitute
a start bit. The SGL/DIFF bit follows the start bit and will
determine if the conversion will be done using single
ended or differential input mode.

Program atmega16's SPI module as per protocol described in ADC datasheet...

Use your ref02 as the reference; your reference can be anywhere between 0.4v and Vdd, which is in the ADC datasheet. Max Vdd is 7.0v, which is also in the datasheet.

I would start by reading the datasheets.