8 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.

8.1 Application Information

LM2901-Q1 family will typically be used to compare a single signal to a reference or two signals against each

other. Many users take advantage of the open drain 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 LM2901-Q1 optimal

for level shifting to a higher or lower voltage.

8.2 Typical Application

V

SUP

V

xIN+

V

REF

+

C

L

R

PULLUP

V

LOGIC

–

½ LM2901x-Q1

V

xIN+

V

xIN–

C

L

R

PULLUP

–

½ LM2901x-Q1

V

SUP

V

LOGIC

Copyright © 2016, Texas Instruments Incorporated

Figure 8-1. Single-Ended and Differential Comparator Configurations

8.2.1 Design Requirements

For this design example, use the parameters listed in Table 8-1 as the input parameters.

Table 8-1. Design Parameters

PARAMETER

EXAMPLE VALUE

Input voltage range

0 V to VSUP – 1.5 V

Supply voltage

2 V to 36 V

Logic supply voltage

2 V to 36 V

Output current (RPULLUP)

1 µA to 20 mA

Input overdrive voltage

100 mV

Reference voltage

2.5 V

Load capacitance (CL)

15 pF

8.2.2 Detailed Design Procedure

8.2.2.1 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 0 V to VCC– 2.0 V. This limits

the input voltage range to as high as VCC– 2.0 V and as low as 0 V. Operation outside of this range can yield

incorrect comparisons.

Below is a list of input voltage situation and their outcomes:

1. When both IN- and IN+ are both within the common mode range:

a. If IN- is higher than IN+ and the offset voltage, the output is low and the output transistor is sinking

current

LM2901-Q1, LM2901V-Q1, LM2901AV-Q1, LM2901B-Q1

SLCS142G – DECEMBER 2003 – REVISED MARCH 2023

www.ti.com

18

Submit Document Feedback

Copyright © 2023 Texas Instruments Incorporated

Product Folder Links: LM2901-Q1 LM2901V-Q1 LM2901AV-Q1 LM2901B-Q1