Data Sheet

AD5750/AD5750-1/AD5750-2

Rev. D | Page 23 of 36

THEORY OF OPERATION

The AD5750/AD5750-1/AD5750-2 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/AD5750-2 is provided from a

low voltage, single-supply 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/AD5750-2) 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, 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/AD5750-2 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/AD5750-2 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/AD5750-2, can be supplied

from a reference such as the ADR392. The AD5750/AD5750-1/

AD5750-2 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.

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

VDD

AGND

VSS

GND

AD5750/

AD5750-1/

AD5750-2

Figure 51. Typical System Configuration in Software Mode (Pull-Up Resistors Not Shown for Open-Drain Outputs)