ADS7056
ZHCSG66 –MARCH 2017
www.ti.com.cn
8.4.3.2 Offset Calibration During Normal Operation
During normal operation, the host must provide 64 SCLKs in the serial transfer frame to enter the OFFCAL state.
The device provides the conversion result for the previous sample during the first 18 SCLKs and 0's on SDO for
the rest of the SCLKs in the serial transfer frame. For acquisition of the next sample, a minimum time of tACQ
must be provided. If the host controller enters the OFFCAL state, but pulls the CS high before providing 64
SCLKs, then the offset calibration process is aborted and the device enters ACQ state. Figure 42 and Table 3
provide the timing for offset calibration during normal operation.
Sample
A
Sample
A+1
tCYCLE
tACQ
CS
SCLK
SDO
4
16
17
64
1
2
3
D12
D0
0
0
0
D13
Data Output for Sample A-1
Figure 42. Timing for Offset Calibration During Normal Operation
Table 3. Timing Specifications for Offset Calibration During Normal Operation(1)
MIN
64 × tCLK + tACQ
95
TYP
MAX
UNIT
ns
tcycle
tACQ
fSCLK
Cycle time for offset calibration on power-up
Acquisition time
ns
Frequency of SCLK
60
MHz
(1) In addition to the timing specifications of Figure 42 and Table 3, the timing specifications described in Figure 2 and the Timing
Requirements table are also applicable for offset calibration during normal operation.
22
Copyright © 2017, Texas Instruments Incorporated
TI [ TEXAS INSTRUMENTS ]
