AMC7812B datasheet(34/92 Pages) TAOS

34 / 92 page

SDI

DAV

SetICONV

bitto ‘1’

DATA

First

Internal

Trigger

ReadData

DATA

ReadData

SetICONV

bitto ‘1’

Second

Internal

Trigger

FirstConversionof

theChannelsSpecifiedin

theADCChannelRegister

SecondConversionof

theChannelsSpecifiedin

theADCChannelRegister

SDI

DAV

SetICONV

bitto ‘1’

Internal

Trigger

1 s

FirstConversionof

theChannelsSpecifiedin

theADCChannelRegister

SecondConversion

ThirdConversion

b)InternalTrigger,AutoMode:

a)InternalTrigger,DirectMode:

CNVT

DAV

FirstConversionof

theChannelsSpecifiedin

theADCChannelRegister

First

Trigger

b)ExternalTrigger,AutoMode:

1 s

CNVT

DAV

SecondConversionof

theChannelsSpecifiedin

theADCChannelRegister

ThirdConversionof

theChannelsSpecifiedin

theADCChannelRegister

First

Trigger

Second

Trigger

Third

Trigger

FirstConversionof

theChannelsSpecifiedin

theADCChannelRegister

SecondConversionof

theChannelsSpecifiedin

theADCChannelRegister

ThirdConversionof

theChannelsSpecifiedin

theADCChannelRegister

a)ExternalTrigger,DirectMode:

AMC7812B

SBAS625A – SEPTEMBER 2013 – REVISED SEPTEMBER 2013

www.ti.com

Figure 85. ADC External Trigger

Figure 84. ADC Internal Trigger

Data Available Pin (DAV)

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

converted and the ADC is 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 are sequentially converted, a 1-µs 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

converting the current channel. After the current channel completes, 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 CH0 to CH3 analog inputs and the temperature inputs are implemented with out-of-range detection. When

any of these inputs 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 + 0.2 V or AGND – 0.2 V. 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.

Submit Documentation Feedback

Product Folder Links: AMC7812B

AMC7812B Datasheet(PDF) 34 Page - TEXAS ADVANCED OPTOELECTRONIC SOLUTIONS

AMC7812B Datasheet(HTML) 34 Page - TEXAS ADVANCED OPTOELECTRONIC SOLUTIONS

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92

Datasheet Download

Link URL