The example below describes how to initialize and perform a single-ended conversion at AIN2 for a single conversion. This is only to help getting started with using the ADC, and assumes that the SPI communication is properly setup. The exact settings will need to be modified according to the application. Please refer to pg 37 of the MAX11410 datasheet for information on SPI Interface. There are three sets of registers for control, status, and data. The 8-bit registers control conversion and power modes, multiplexer connections, and other functions, and should cover most/all of initialization. The 8-bit registers are at least sufficient for initializing the ADC in this example. The 8-bit register map can be found on page 39 of the datasheet. The registers to be set are highlighted. Example Initialization Settings These registers can be set sequentially starting from 0x00. The major purposes for setting the registers below is to 1. turn on the device 2. select appropriate reference voltage sources, clock sources, and data format 3. select the analog inputs to convert to digital output 4. switch off/disconnect bias sources from the analog inputs, etc. - PD[7:0] (Addr 0x00, Value: 0x00). This sets the ADC in normal mode. - CTRL[7:0] (Addr 0x09, Value: 0x01). Uses the internal clock, bipolar input range, two's complement format, power down the reference P-side and N-side buffer and bypass, selects REF1P and REF1N as reference voltage. - SOURCE[7:0](Addr 0x0A, Value: 0x80). Sets Vbias mode to low impedance, 20kohm output impedance, disable burnout source, set excitation current source IDAC to 10uA. This register is not that essential to perform the necessary conversion for this example as bias voltage and excitation current sources are not used as described in the following registers. - MUX_CTRL0[7:0](Addr 0x0B, Value: 0x2A). Selects AIN2 as positive input and GND as negative input to convert to digital output. - MUX_CTRL1[7:0](Addr 0x0C, Value: 0xFF) Disable and disconnect both excitation current sources from the analog inputs - MUX_CTRL2[7:0](Addr 0x0D, Value: 0x00) Disconnect voltage bias source from all analog inputs. - PGA[7:0] (Addr 0x0E, Value: 0x00). It adds a buffer between the output of the mux that routes the differential analog input to convert (AIN2 and GND), and the modulator. Gain is set to 1. After initializing the ADC, refer to the Single Conversion section below. Single Conversion The idea is to setup the interrupt enable register such that the interrupt pin goes low when the conversion is ready. Then, send a conversion start command to start a single cycle conversion. When the result is ready, read the status and the corresponding data register. Please refer to DOUT/INTB section on page 37 for details on interrupt pin. The register settings below should be set and read following the sequence below. 1. Write to Status_IE(Addr: 0x39, Value: 0x000001). Set CONV_RDY_IE bit of Status_IE(0x39) to 1. That way, the INTB can be used as a interrupt source to the microcontroller when data is ready. Please note that this is a 24 bit register. 2. Write to CONV_START[7:0] (Addr 0x01, Value: 0x00) This will begin a single conversion and stores the result in DATA0 register when it's done. 3. Read Status Register(Addr: 0xB8 for reading) After waiting until the data is ready, read the status register to clear the register. If you prefer to not use the hardware interrupt pin in step 1, the alternative is to keep reading the status register until the CONV_RDY bit of the status register is set. 4. Read Data0 register(Addr 0xB0 for reading) Finally, read data0 register for the conversion result.