AD7713(RevC) Ver la hoja de datos (PDF) - Analog Devices
Número de pieza
componentes Descripción
Fabricante
AD7713 Datasheet PDF : 28 Pages
| |||
AD7713
CONTROL REGISTER (24 BITS)
A write to the device with the A0 input low writes data to the control register. A read to the device with the A0 input low accesses the
contents of the control register. The control register is 24 bits wide and when writing to the register 24 bits of data must be written
otherwise the data will not be loaded to the control register. In other words, it is not possible to write just the first 12 bits of data into
the control register. If more than 24 clock pulses are provided before TFS returns high, then all clock pulses after the 24th clock
pulse are ignored. Similarly, a read operation from the control register should access 24 bits of data.
MSB
2
MD2 MD1 MD0 G2 G1 G0 CH1 CH0 WL RO BO B/U
FS11 FS10 FS9 FS8 FS7 FS6 FS5 FS4 FS3 FS2 FS1 FS0
LSB
Operating Mode
MD2 MD1 MD0 Operating Mode
0
0
0
Normal Mode. This is the normal mode of operation of the device whereby a read to the device with A0
high accesses data from the data register. This is the default condition of these bits after the internal
power-on reset.
0
0
1
Activate Self-Calibration. This activates self-calibration on the channel selected by CH0 and CH1. This
is a one-step calibration sequence, and when complete, the part returns to Normal Mode (with MD2,
MD1, MD0 of the control registers returning to 0, 0, 0). The DRDY output indicates when this self-
calibration is complete. For this calibration type, the zero-scale calibration is done internally on shorted
(zeroed) inputs and the full-scale calibration is done on VREF.
0
1
0
Activate System Calibration. This activates system calibration on the channel selected by CH0 and CH1.
This is a two-step calibration sequence, with the zero-scale calibration done first on the selected input
channel and DRDY indicating when this zero-scale calibration is complete. The part returns to Normal
Mode at the end of this first step in the two-step sequence.
0
1
1
Activate System Calibration. This is the second step of the system calibration sequence with full-scale
calibration being performed on the selected input channel. Once again, DRDY indicates when the full-
scale calibration is complete. When this calibration is complete, the part returns to Normal Mode.
1
0
0
Activate System Offset Calibration. This activates system offset calibration on the channel selected by
CH0 and CH1. This is a one-step calibration sequence and, when complete, the part returns to Normal
Mode with DRDY indicating when this system offset calibration is complete. For this calibration type,
the zero-scale calibration is done on the selected input channel and the full-scale calibration is done
internally on VREF.
1
0
1
Activate Background Calibration. This activates background calibration on the channel selected by CH0
and CH1. If the background calibration mode is on, then the AD7713 provides continuous self-
calibration of the reference and shorted (zeroed) inputs. This calibration takes place as part of the con-
version sequence, extending the conversion time and reducing the word rate by a factor of six. Its major
advantage is that the user does not have to worry about recalibrating the device when there is a change
in the ambient temperature. In this mode, the shorted (zeroed) inputs and VREF, as well as the analog
input voltage, are continuously monitored and the calibration registers of the device are updated.
1
1
0
Read/Write Zero-Scale Calibration Coefficients. A read to the device with A0 high accesses the contents
of the zero-scale calibration coefficients of the channel selected by CH0 and CH1. A write to the device
with A0 high writes data to the zero-scale calibration coefficients of the channel selected by CH0 and
CH1. The word length for reading and writing these coefficients is 24 bits, regardless of the status of the
WL bit of the control register. Therefore, when writing to the calibration register, 24 bits of data must be
written, otherwise the new data will not be transferred to the calibration register.
1
1
1
Read/Write Full-Scale Calibration Coefficients. A read to the device with A0 high accesses the contents of
the full-scale calibration coefficients of the channel selected by CH0 and CH1. A write to the device
with A0 high writes data to the full-scale calibration coefficients of the channel selected by CH0 and
CH1. The word length for reading and writing these coefficients is 24 bits, regardless of the status of the
WL bit of the control register. Therefore, when writing to the calibration register, 24 bits of data must be
written, otherwise the new data will not be transferred to the calibration register.
REV. C
–9–
Share Link: 