Datasheet

AD7156
Rev. 0 | Page 20 of 28
CONFIGURATION REGISTER
Address Pointer 0x0F
8 Bits, Read/Write, Factory Preset 0x19
Table 12. Configuration Register Bit Map
1
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
ThrFixed ThrMD1 ThrMD0 EnCh1 EnCh2 MD2 MD1 MD0
(0) (0) (0) (1) (1) (0) (0) (1)
1
The default values are given in parentheses.
Table 13.Configuration Register Bit Descriptions
Bit Mnemonic Description
7 ThrFixed
ThrFixed = 1 sets the fixed threshold mode; the outputs reflect the comparison of data and a fixed (constant)
value of the threshold registers.
ThrFixed = 0 sets the adaptive threshold mode; the outputs reflect the comparison of data to the adaptive
thresholds. The adaptive threshold is set dynamically, based on the history of the previous data.
6
5
ThrMD1
ThrMD0
These bits set the output comparators mode
ThrMD1 ThrMD0 Threshold Mode
Output Active When
Adaptive Threshold Mode Fixed Threshold Mode
0 0 Negative Data < average – sensitivity Data < threshold
0 1 Positive Data > average + sensitivity Data > threshold
1 0 In-window Data > average – sensitivity
and
Data < average + sensitivity
1 1 Out-window Data < average – sensitivity
or
Data > average + sensitivity
4 EnCh1 Enables conversion on Channel 1
3 EnCh2 Enables conversion on Channel 2
2
1
0
MD2
MD1
MD0
Converter mode of operation setup
MD2 MD1 MD0 Mode Description
0 0 0 Idle The part is fully powered up, but performing no conversion.
0 0 1
Continuous
Conversion
The part is repeatedly performing conversions on the
enabled channel(s); if two channels are enabled, the part is
sequentially switching between them.
0 1 0 Single conversion
The part performs a single conversion on the enabled
channel; if two channels are enabled, the part performs two
conversions, one on each channel. After finishing the
conversion(s), the part goes to the idle mode.
0 1 1 Power-down
The part powers down the on-chip circuits, except the
digital interface.
1 X X Reserved Do not use these modes.