Datasheet

EVAL-AD5420
Rev. 0 | Page 6 of 12
The main window is divided into eight sections: Input Register,
Status Register, Control Register, Reset Register, Clear Pin,
Read/Write Registers, Measure Output Current, and Program
Current.
Input Register
The Input Register section displays the contents of the input
register. The 24-bit display is updated each time you request a
read or a write operation via the main window controls. It
allows you to associate the value written to the AD5420 with the
various programmable functions.
Status Register
The Status Register section displays the states of the three bits
of the read-only status register. To read the register, click the
Read Status Register button.
Control Register
The Control Register section facilitates programming of the
control register on an individual bit basis. To change the value
for a bit, click the relevant button. Each button also displays the
current state of the bit. You can also enter code in the SR
CLOCK and SR STEP text boxes and select an output range
from the OUTPUT RANGE drop-down box.
Reset Register
The sole function of the Reset Register section is to allow the
AD5420 to be reset to its power-on state. To change the value of
the reset bit, click the RESET button.
Clear Pin
In the Clear Pin section, you can change the state of the
CLEAR pin by clicking the CLEAR button.
Read/Write Registers
In the Read/Write Registers section, you can read and write to
all registers in the AD5420. To select a register and request a
read or write, click the Select Control Function box. Then, to
write data to the register, click the Data Write button until the
desired data is displayed in the Data Write text box; then click
OK. Register data is updated and displayed for you to read in
the Data Read text box each time you click OK.
Measure Output Current
To display the programmed output current in the Measure
Output Current section, click the Measure output Current
button. The output current is measured using the on-board
ADC and is displayed in milliamperes (mA) in the I
OUT
box.
The output current is measured with an accuracy of
approximately 1% and is, therefore, not intended as precise, but
rather as an approximate, feedback of the programmed current.
Program Current
To program a current output value, enter the value in milli-
amperes (mA) in the Enter Value text box of the Program
Current section, and press Enter. The output must first be
enabled ,and the output range must be selected via the Control
Register section.