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2 adc data buffer (addata when adcfg = 0), Table 6-3 . adc data bit weighting -9, Table6-3.adcdatabitweighting – Maxim Integrated MAX31782 User Manual

Page 52: 2adcdatabuffer(addatawhenadcfg=0)

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MaximIntegrated 6-9

MAX31782 User’s Guide

Revision 0; 8/11

6.2.4.2ADCDataBuffer(ADDATAwhenADCFG=0)

When ADCFG = 0, reading from the ADDATA register reads the ADC results stored in one of the 16 data buffers . The
data buffer to read from is selected with the ADIDX[3:0] bits . Reading this register returns the 13-bit (12-bits plus a sign
bit) ADC conversion data plus selected data buffer memory . The ADIDX[3:0] bits automatically increment after a read of
ADDATA . This allows multiple reads of ADDATA to access consecutive data buffer locations without needing to change
ADIDX . The data buffers are reset to 0 on all forms of reset and are not writable by the user .
The data that is read from the ADC buffer can be from either a temperature or voltage conversion . Also, the data can
be right-aligned or left-aligned .

Table 6-3

shows the returned bit weighting for each type of conversion .

Table6-3.ADCDataBitWeighting

3

ADDIFF

ADC Differential Mode Select . In voltage mode, this bit selects the ADC conversion mode . When
this bit is set to 1, the ADC conversion is in differential mode . When this bit is cleared to 0, the ADC
conversion is performed in single-ended mode . During single-ended mode, the sample is measured
between AD0P–AD5P and ground . If AD0P–AD5P transitions below 0, negative numbers are reported .
No clamping of data is performed for negative inputs . The firmware needs to clamp the negative read-
ing . In temperature mode, ADDIFF is a “don’t care .” The part automatically selects differential mode
for temperature measurement .

2:0

ADCH[2:0]

ADC Channel Select . These bits select the input channel source for the current ADC conversion .

ADCH[2:0]

ADDIFF=0

ADDIFF=1

000

AD0P

AD0P–AD0N

001

AD1P

AD1P–AD1N

010

AD2P

AD2P–AD2N

011

AD3P

AD3P–AD3N

100

AD4P

AD4P–AD4N

101

AD5P

AD5P–AD5N

11X

Internal Temperature Mode

Bit

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Temperature Right-
Aligned

S

S

S

S

2

8

2

7

2

6

2

5

2

4

2

3

2

2

2

1

2

0

2

-1

2

-2

2

-3

Temperature Left-
Aligned

S

2

8

2

7

2

6

2

5

2

4

2

3

2

2

2

1

2

0

2

-1

2

-2

2

-3

0

0

0

Voltage Right-Aligned

S

S

S

S

2

11

2

10

2

9

2

8

2

7

2

6

2

5

2

4

2

3

2

2

2

1

2

0

Voltage Left-Aligned

S

2

11

2

10

2

9

2

8

2

7

2

6

2

5

2

4

2

3

2

2

2

1

2

0

0

0

0