Datasheet

AD7292 Data Sheet
Rev. 0 | Page 32 of 40
MINIMUM AND MAXIMUM REGISTER BANK
(ADDRESS 0x08)
The minimum and maximum register bank contains the mini-
mum and maximum conversion values for each of the eight
analog input channels and the temperature sensor channel.
Values are 10-bit, left justified.
The minimum and maximum subregisters are cleared when a
value is written to them—that is, they return to their power-up
values. This means that if a subregister is accessed with both the
read and write bits set, the stored minimum or maximum value
can be read and reset in one operation. On power-up, the mini-
mum value subregisters contain 0xFFC0, and the maximum value
subregisters contain 0x0000.
Table 35. Minimum and Maximum Register Bank Subregisters
1
Bits in the minimum and maximum subregisters can be reset by writing 1 to
the selected bits.
OFFSET REGISTER BANK (ADDRESS 0x09)
The offset register bank contains nine subregisters. Each of the
eight analog input channels, as well as the temperature sensor
channel, has a corresponding offset register (see Table 36).
Table 36. Offset Register Bank Subregisters
Subaddress (Hex) Subregister Name
1
0x00 VIN0 offset
0x01 VIN1 offset
0x02 VIN2 offset
0x03 VIN3 offset
0x04 VIN4 offset
0x05 VIN5 offset
0x06 VIN6 offset
0x07 VIN7 offset
0x10 Temperature sensor offset
1
All subregisters in the offset register bank are read/write.
Each 8-bit, read/write offset subregister stores data in twos
complement format. Values are added to the ADC conversion
results. The offset encoding scheme used for the analog input
channels and the temperature sensor are shown in Table 39 and
Table 40, respectively. The default value for all subregisters in
the offset register bank is 0x00.
When bits in these subregisters are set, the offset value is cumula-
tive. Table 37 provides examples of analog input channel values,
and Table 38 provides examples of temperature sensor channel
values.
Table 37. Examples of Analog Input Channel Offset Values
Offset Subregister Value Offset Value (LSB)
10000000 −32
11000000 −16
00001000 +2
Table 38. Examples of Temperature Sensor Channel Offset
Values
Offset Subregister Value Offset Value (°C)
10000000 −16
11000000 −8
00001000 +1
Table 39. VIN0 to VIN7 Offset Encoding Scheme
D7 D6 D5 D4 D3 D2 D1 D0
−32 LSB +16 LSB +8 LSB +4 LSB +2 LSB +1 LSB +0.5 LSB +0.25 LSB
Table 40. Temperature Sensor Offset Encoding Scheme
D7 D6 D5 D4 D3 D2 D1 D0
−16°C +8°C +4°C +2°C +1°C +0.5°C +0.25°C +0.125°C
Subaddress (Hex) Subregister Name
1
0x00 VIN0 maximum value
0x01 VIN0 minimum value
0x02 VIN1 maximum value
0x03 VIN1 minimum value
0x04 VIN2 maximum value
0x05 VIN2 minimum value
0x06 VIN3 maximum value
0x07 VIN3 minimum value
0x08 VIN4 maximum value
0x09 VIN4 minimum value
0x0A VIN5 maximum value
0x0B VIN5 minimum value
0x0C VIN6 maximum value
0x0D VIN6 minimum value
0x0E VIN7 maximum value
0x0F VIN7 minimum value
0x10 to 0x1F Reserved
0x20 T
SENSE
maximum value
0x21 T
SENSE
minimum value
0x22 to 0xFF Reserved