7 Application and Implementation

Note

Information in the following applications sections is not part of the TI component specification,

and TI does not warrant its accuracy or completeness. TI’s customers are responsible for

determining suitability of components for their purposes, as well as validating and testing their design

implementation to confirm system functionality.

7.1 Application Information

TL331-Q1 is typically used to compare a single signal to a reference or two signals against each other. Many

users take advantage of the open collector output to drive the comparison logic output to a logic voltage level to

an MCU or logic device. The wide supply range and high voltage capability makes TL331-Q1 an excellent choice

for level shifting to a higher or lower voltage.

7.2 Typical Application

+

TL331

5 V

5 V

Vref

Input 0 V to 30 V

Figure 7-1. Typical Application Schematic

7.2.1 Design Requirements

For this design example, use the parameters listed in Table 7-1 as the input parameters.

Table 7-1. Design Parameters

DESIGN PARAMETER

EXAMPLE VALUE

Input Voltage Range

0V to VCC – 1.5V

Supply Voltage

2V to 36V

Logic Supply Voltage (RPULLUP Voltage)

2V to 36V

Output Current (VLOGIC/RPULLUP)

1µA to 4mA

Input Overdrive Voltage

100mV

Reference Voltage

2.5V

Load Capacitance (CL)

15pF

7.2.2 Detailed Design Procedure

When using TL331-Q1 in a general comparator application, determine the following:

• Input voltage range

• Minimum overdrive voltage

• Output and drive current

• Response time

7.2.2.1 Input Voltage Range

When choosing the input voltage range, the input common mode voltage range (VICR) must be taken in to

account. If temperature operation is above or below 25°C the VICR can range from 0V to VCC – 1.5V. This limits

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TL331-Q1, TL331B-Q1, TL391B-Q1

SLVS969H – OCTOBER 2009 – REVISED JANUARY 2025

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