User Guide

EVAL-AD74115H

SOFTWARE QUICK START PROCEDURES

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Rev. 0 | 11 of 24

DEVICE FUNCTION NOTES

The following sections outline the load connectivity and hardware

requirements for the various functions of the AD74115H.

Analog Outputs, Analog Input, and Digital

Input Functions

Connect all loads between the I/OP and I/ON screw terminals.

Use the channel view dropdown menus to select the function of

choice and configure the advanced settings as required.

Resistance Measurements

Take the 2-wire resistance measurements between the I/OP and

I/ON screw terminals.

When measuring the 3-wire resistance temperature detectors

(RTDs) with the evaluation GUI, connect the RTD as follows:

►

Connect Lead 1 of the 3-wire RTD to the I/OP screw terminal.

►

Connect Lead 2 of the 3-wire RTD to the SENSE_EXT1 terminal.

►

Connect Lead 3 of the 3-wire RTD to the I/ON screw terminal.

When measuring the 4-wire RTDs with the evaluation GUI, connect

the RTD as follows:

►

Connect Lead 1 of the 4-wire RTD to I/OP terminal and connect

its sense, Lead 2, to the SENSE_EXT2 terminal.

►

Connect Lead 3 of the 4-wire RTD to I/ON terminal and connect

its sense, Lead 4, to the SENSE_EXT1 terminal.

For the best 3-wire and 4-wire measurement results, configure

the excitation current and ADC measurement range to suit the

chosen RTD range. Three measurement ranges are described in

the AD74115H data sheet, along with the proposed measurement

settings.

Digital Output

The ADP1034 can provide the power required to power the internal

digital output function. When using the internal digital output func-

tion, connect the DO_VDD power supply to be AVDD by connecting

Pin 2 to Pin 3 of P15.

Configure the EVAL-AD74115H-ARDZ board correctly before set-

ting the AD74115H as a digital output. The jumper settings required

for the various internal digital output functions are outlined in Table

2.

For the external digital output, an additional power supply is

required to provide current to the external field-effect transistors

(FETs).

When using the external digital output function, connect the

DO_VDD power supply to be DO_SUPPLY terminal by connecting

Pin 1 to Pin 2 of P15.

Take care with the external FETs because these FETs can be

thermally damaged if short-circuit times are set too long. The FETs

chosen for the external digital output function are the following:

►

SI7113ADN-T1-GE3: P-channel metal-oxide semiconductor

(PMOS) FET for sourcing current

►

SIA416DJ-T1-GE3: N-channel MOS (NMOS) FET for sinking

current

Table 2. Jumper Connections for Digital Output Modes

Digital Output Function

JP2

P6

P7

P12

P13

Internal Digital Output

Open

Pin 1 to Pin 2

Pin 1 to Pin 2

Pin 2 to Pin 3

Pin 2 to Pin 3

External Digital Output

Open

Pin 2 to Pin 3

Pin 2 to Pin 3

Pin 2 to Pin 3

Pin 2 to Pin 3

External Digital Output with Smart Diode

Closed

Pin 2 to Pin 3

Pin 2 to Pin 3

Pin 1 to Pin 2

Pin 1 to Pin 2