Datasheet

AD5750/AD5750-1
Rev. C | Page 23 of 36
THEORY OF OPERATION
The AD5750/AD5750-1 are single-channel, precision voltage/
current output drivers with hardware- or software-programmable
output ranges. The software ranges are configured via an SPI-/
MICROWIRE-compatible serial interface. The analog input to
the AD5750/AD5750-1 is provided from a low voltage, single-
supply digital-to-analog converter (DAC) and is internally
conditioned to provide the desired output current/voltage range.
Analog input ranges available are 0 V to 2.5 V (AD5750-1) or
0 V to 4.096 V (AD5750).
The output current range is programmable across five current
ranges: 4 mA to 20 mA, 0 mA to 20 mA or 0 mA to 24 mA,
±20 mA, and ±24 mA.
The voltage output is provided from a separate pin that can be
configured to provide 0 V to 5 V, 0 V to 10 V, ±5 V, or ±10 V
output ranges. An overrange of 20% is available on the voltage
ranges. An overrange of 2% is available on the 4 mA to 20 mA,
0 mA to 20 mA, and 0 mA to 24 mA current ranges. The
current and voltage outputs are available on separate pins. Only
one output can be enabled at one time. The output range is
selected by programming the R3 to R0 bits in the control
register (see Table 7 and Table 8 ).
Figure 51 and Figure 52 show a typical configuration of the
AD5750/AD5750-1 in software mode and in hardware mode,
respectively, in an output module system. The HW SELECT pin
selects whether the part is configured in software or hardware
mode. The analog input to the AD5750/AD5750-1 is provided
from a low voltage, single-supply DAC such as the AD506x or
AD566x, which provides an output range of 0 V to 4.096 V. The
supply and reference for the DAC, as well as the reference for the
AD5750/AD5750-1, can be supplied from a reference such as the
ADR392. The AD5750/AD5750-1 can operate from supplies up
to ±26.4 V.
SOFTWARE MODE
In current mode, software-selectable output ranges include
±20 mA, ±24 mA, 0 mA to 20 mA, 4 mA to 20 mA, and 0 mA
to 24 mA.
In voltage mode, software-selectable output ranges include 0 V
to 5 V, 0 V to 10 V, ±5 V, and ±10 V.
07268-045
VSENSE+
VSENSE–
VIN
SCLK
VDD REFIN
SDI/DIN
SDO
SYNC1
SYNC
SDO
SDIN
SCLK
AD506x
AD566x
MCU
VOUT
0V TO +5V, 0V TO +10V
,
±5V, ±10V
IOUT
0mA TO +20mA,
0mA TO +24mA,
+4mA TO +20mA,
±20mA, ±24mA
VOUT
RANGE
SCALE
IOUT
RANGE
SCALE
VOUT SHORT FAULT
IOUT OPEN FAULT
OVERTEMP FAULT
STATUS REGISTER
SERIAL
INTERFACE
VREF
HW SELECT
FAULT
ADP1720
ADR392
V
DD
A
GND
V
SS
AVDD GND AVSS
AD5750/AD5750-1
Figure 51. Typical System Configuration in Software Mode (Pull-Up Resistors Not Shown for Open-Drain Outputs)