RWb

3Ÿ

Rwa

3Ÿ

Pt100 RTD

+

RTD Resistance

(Volts = Ohms)

VRTD

EMU21 RTD3

VT+

VT-

RTD+

RTD-

Mon-

Mon-

±

VT 25

RWd

3Ÿ

RWc

4Ÿ

Temp (°C)

(Volts = °C)

±

+

+

3 V

U2

OPA333-Q1

100 NŸ

100 Ÿ

U1 INA333-Q1

3 V

Use BF861A

Use BF861A

3 V

±

+

±

+

3 V

U3

OPA333-Q1

T1 BF256A

T3 BF256A

+

+

V

+

+

A

A

±

+

3 V

2 NŸ

RG

RG

V-

V+

Ref

Out

2

1

8

3

7

5

6

2.5 NŸ

2.5 NŸ

In

EN

OUTF

OUTS

GNDS

GNDF

3 V

+

V4 3

3 V

470 nF

U1 REF3212

PGA112

MSP430

OPA333-Q1

21

INA333-Q1

www.ti.com

SBOS464 – OCTOBER 2019

Product Folder Links: INA333-Q1

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Copyright © 2019, Texas Instruments Incorporated

11 Device and Documentation Support

11.1 Device Support

11.1.1 Development Support

11.1.1.1 TINA-TI (Free Download Software)

Using TINA-TI SPICE-Based Analog Simulation Program with the INA333-Q1

TINA is a simple, powerful, and easy-to-use circuit simulation program based on a SPICE engine. TINA-TI is a

free, fully functional version of the TINA software, preloaded with a library of macromodels in addition to a range

of both passive and active models. It provides all the conventional dc, transient, and frequency domain analysis

of SPICE as well as additional design capabilities.

Available as a free download from the Analog eLab Design Center, TINA-TI offers extensive post-processing

capability that allows users to format results in a variety of ways.

Virtual instruments offer users the ability to select input waveforms and probe circuit nodes, voltages, and

waveforms, creating a dynamic quick-start tool.

Figure 41 shows example TINA-TI circuits for the INA333-Q1 device that can be used to develop, modify, and

assess the circuit design for specific applications. Links to download these simulation files are given below.

NOTE

These files require that either the TINA software (from DesignSoft) or TINA-TI software be

installed. Download the free TINA-TI software from the TINA-TI folder.

RWa, RWb, RWc, and RWd simulate wire resistance. These resistors are included to show the four-wire sense technique immunity to line

mismatches. This method assumes the use of a four-wire RTD.

Figure 41. Four-Wire, 3-V Conditioner for a PT100 RTD With Programmable Gain Acquisition System

Download the TINA-TI simulation file for this circuit with the following link: PT100 RTD.