ad5933 Analog Devices, Inc., ad5933 Datasheet - Page 14

• Manufacturer Part Number: ad5933
• Description: 1 Msps 12-bit Impedance Converter, Network Analyzer
• Manufacturer: Analog Devices, Inc.

AD5933
CONTROL REGISTER DECODE:
INITIALIZE SENSOR WITH START FREQUENCY
This command enables the DDS to output the start frequency
for an indefinite time. It is used is to excite the sensor initially.
When the output load (sensor) has settled after a time
determined by the user, the user must initiate a “start frequency
sweep” command to begin the frequency sweep.
START FREQUENCY SWEEP
This command start the frequency sweep routine. When the
AD11/2043 receives this command, it starts counting a delay
cycle that will gate the ADC conversion pulse. This delay cycle
has already been pre-programmed as number of output cycles
by the user.
INCREMENT FREQUENCY
The “Increment Frequency” command is used to step to the
next frequency point in the sweep. This usually happens after
data from the previous step has been transferred and verified by
the DSP.
REPEAT FREQUENCY
Repeat frequency allows the user to repeat any given frequency
if the data gets corrupted or the measurement sequence doesn’t
complete.
POWER DOWN
Power Down powers down all the blocks in the chip except the
interface. All amplifiers and the oscillator will be powered off.
The default on power-up of the AD11/2043 is power-down and
the control register will contain the code 1010000000000000. In
this mode both the output and input pins DDS_OUT and
IN_ADC will be tied to GND.
Rev. PrA | Page 14 of 20
STANDBY MODE
Powers the part up for general operation; all the amplifiers will
be powered up but their outputs will be tied to GND. The
internal oscillator will also be powered up and running.
READ TEMPERATURE
This initiates a temperature reading from the part. The part
does not need to be in Power Up mode to perform a
temperature reading. The block will power itself up, take the
reading and then power down again.
ERROR CHECKING
Set bit in Control Register to enable this. Enable = “1”;
Disable=”0”
RESET
A Reset will Refresh all Memory, Reset ADC, Frequency reverts
to the INITIAL start frequency
SYSTEM CLOCK
Allows the user to configure either the internal oscillator, an
external reference clock or to allow an internal PLL to provide a
clock for the system. In PLL mode the user will have to provide
a stable ~32khz clock as reference to the PLL.
OUTPUT VOLTAGE
This allows the user to change the excitation voltage levels.
There are for output ranges, 2v, 1v, 500mv, 200mv.
POST GAIN
Allows the user to multiply pre-amp the response signal by a
multiplication factor of 5 into the ADC if required.
Preliminary Technical Data