Datasheet
ADS7863
www.ti.com
SBAS383E –JUNE 2007–REVISED JANUARY 2011
DIGITAL DP: Deep power-down enable ('1' = device in
deep power-down mode)
This section addresses the timing and control of the
N: Nap power-down enable ('1' = device in Nap
ADS7863 serial interface.
power-down mode)
AN: AutoNap power-down enable ('1' = device in
Serial Data Input (SDI)
AutoNap power-down mode)
The serial data input or SDI pin is coupled to RD and
RP: Reference power-down ('1' = reference
clocked into the ADS7863 on each falling edge of
turned off)
CLOCK. The data word length of the SDI Register is
S4: Special read mode for Modes II and IV
12 bits. Table 3 shows the register structure. The
('1' = special mode enabled)
data must be transferred MSB-first. Table 4 through
Table 6 describe specific bits of this register. The
Table 6. A2, A1, and A0: DAC Control and Device
default value of this register after power-up is 0x000.
Reset
Table 3. SDI Register Contents
A2 A1 A0 FUNCTION
0 0 0 No action
SDI REGISTER BIT
0 0 1 DAC write with next access
11 10 9 8 7 6 5 4 3 2 1 0
0 1 0 No action
C1 C0 P1 P0 DP N AN RP S4 A2 A1 A0
0 1 1 DAC read with next access
1 0 0 No action
Table 4. C1 and C0: Channel Selection
1 0 1 Device reset
ADC A/B
1 1 0 No action
C1 C0 POSITIVE INPUT NEGATIVE INPUT
1 1 1 No action
0 0 CHA0+/CHB0+ CHA0–/CHB0–
0 1 CHA1–/CHB1– CHA0–/CHB0–
All additional features become active with the rising
1 0 CHA1+/CHB1+ CHA0–/CHB0–
edge of the 12th CLOCK signal after issuing the RD
1 1 CHA1+/CHB1+ CHA1–/CHB1–
pulse.
The reference DAC is controlled by the 12-bit DAC
Table 5. P1 and P0: Additional Features Enable
register that can also be accessed using the SDI pin
(see Figure 40 for details). Table 7 shows the content
P1 P0 FUNCTION
of this register; the default value after power-up is
0 0 Additional features are not changed
0x3FF.
0 1 Update additional features
1 0 Reserved for factory test (do not
use)
1 1 Additional features are not changed
Table 7. DAC Register Contents
DAC REGISTER CONTENT
11 10 9 8 7 6 5 4 3 2 1 0
X
(1)
X MSB Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
(1) X = don't care.
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