AMC7812SPAPR datasheet(34/92 Pages) TI

34 / 92 page

AMC7812

SBAS513E – JANUARY 2011 – REVISED SEPTEMBER 2013

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Data Available Pin (DAV)

DAV is an output pin that indicates the completion of ADC conversions. The DAVF bit in AMC Configuration

been converted and the ADC has been stopped, the DAVF bit is set to '1' and the DAV pin is driven to logic low

(active). In ADC auto mode, each time the group of input channels have been sequentially converted, a 1µs

pulse (low) appears on the DAV pin.

Convert Pin (CNVT)

CNVT is the input pin for the external ADC trigger signal. ADC channel conversions begin on the falling edge of

the CNVT pulse. If a CNVT pulse occurs when the ADC is already converting, then the ADC continues

conversion of the current channel. After the completion of the current channel, the existing conversion cycle

finishes and a new conversion cycle starts. The selected channels specified in the ADC Channel Registers are

converted sequentially in order of enabled channels.

Analog Input Out-of-Range Detection (see the Analog Input Out-of-Range Alarm Section)

The analog inputs of CH0 to CH3 and the temperature inputs are implemented with out-of-range detection. When

any one of them is out of the preset range, the corresponding alarm flag in the Status Register is set. If any

inputs are out of range, the global out-of-range pin (ALARM) goes low. To avoid a false alarm, the device is

implemented with false-alarm protection. See the Alarm Operation section for more details.

Full-Scale Range of the Analog Input

The Gain bit of the ADC Gain Register determines the full-scale range of the analog input. Full-scale range is

VREF when ADGn = 0, or (2 · VREF) when ADGn = 1. If a channel pair is configured for differential operation, the

input ranges are either ±VREF or ±(2 · VREF). In (2 · VREF) mode, the input is effectively divided by two before the

conversion takes place. Each input must not exceed the supply value of AVDD + 0.2V or AGND - 0.2V. When the

REF-OUT pin is connected to the REF-ADC pin, the internal reference is used as the ADC reference. When an

external reference voltage is applied to the REF-ADC pin, the external reference is used as the ADC reference.

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AMC7812SPAPR Datasheet(PDF) 34 Page - Texas Instruments