MAX11311 Datasheet, PDF (43/51 Pages) Maxim Integrated Products – PIXI, 12-Port Programmable Mixed-Signal I/O with 12-Bit ADC, 12-Bit DAC, Analog Switches, and GPIO

MAX11311
PIXI, 12-Port Programmable Mixed-Signal I/O with
12-Bit ADC, 12-Bit DAC, Analog Switches, and GPIO
Port Configuration Registers (Read/Write)(continued)
BIT
FIELD NAME
DESCRIPTION
• 1001: Mode 9 - Negative analog input to differential ADC
• The port is configured as a differential ADC negative input.
• The number of samples to average is defined by the associated positive port. The
functional parameter RANGE must be identical to that used by the corresponding
positive port.
• A port configured in mode 9 can be associated to more than one port configured in
mode 8.
• Functional parameter to be set: RANGE
• 1010: Mode 10 - Analog output for DAC and negative analog input to differential ADC
(Figure 4)
• While this port drives the voltage corresponding to its DAC data register, it also
operates as the negative input for the ADC.
• The number of samples to average is defined by the associated positive port. The
functional parameter RANGE must be identical to that used by the corresponding
positive port.
• A port configured in mode 10 can be associated to more than one port configured
in mode 8.
• When the ADC input voltage range is set from 0V to 2.5V (RANGE = 100 or 110),
the DAC data register value must be limited to the range of values corresponding
to 0V to 2.5V at the port. Internally, the DAC data register value is clipped, so that
the PIXI port voltage is contained within a range from 0V to 5V to prevent device
damage.
• Functional parameter to be set: RANGE
• 1011: Mode 11 - Terminal to GPI-controlled analog switch (Figure 11)
• In this mode, two adjacent ports can be connected together through an analog
switch controlled by a GPI-configured port (designated by the functional parameter
ASSOCIATED PORT). This function involves three ports. The switch controlling
port needs to be separately configured in GPI mode. Only the port with the lower
index needs to be configured in mode 11. The port with the higher index can be
configured in any other mode, except mode 2. If the port of higher index operates
in an ADC-related mode (mode 6, 7, 8, or 9), the signals applied to the port in
mode 11 must comply with the input voltage range for which the port of higher
index is configured.
• Ports 5 and 11 cannot be configured in mode 11, as there is no switch between
ports 5 and 6 and between ports 11 and 0.
• Functional parameters to be set: INV, ASSOCIATED PORT
• 1100: Mode 12 - Terminal to register-controlled analog switch
• This mode is identical to Mode 11, except that the switch remains closed as long as this
port is configured in mode 12.
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