ADS131M08IPBSR datasheet(20/118 Pages) TI2

20 / 118 page

8.3 Feature Description

8.3.1 Input ESD Protection Circuitry

Basic electrostatic discharge (ESD) circuitry protects the ADS131M08 inputs from ESD and overvoltage events

in conjunction with external circuits and assemblies. Figure 8-1 depicts a simplified representation of the ESD

circuit. The protection for input voltages exceeding AVDD can be modeled as a simple diode.

AINnP

AINnN

AVDD

To analog inputs

Figure 8-1. Input ESD Protection Circuitry

The ADS131M08 has an integrated negative charge pump that allows for input voltages below AGND with a

unipolar supply. Consequently, shunt diodes between the inputs and AGND cannot be used to clamp excessive

negative input voltages. Instead, the same diode that clamps overvoltage is used to clamp undervoltage at its

reverse breakdown voltage. Take care to prevent input voltages or currents from exceeding the limits provided in

the Absolute Maximum Ratings table.

8.3.2 Input Multiplexer

Each channel of the ADS131M08 has a dedicated input multiplexer. The multiplexer controls which signals are

routed to the ADC channels. Configure the input multiplexer using the MUXn[1:0] bits in the CHn_CFG register.

The input multiplexer allows the following inputs to be connected to the ADC channel:

• The analog input pins corresponding to the given channel

• AGND, which is helpful for offset calibration

• Positive DC test signal

• Negative DC test signal

See the Internal Test Signals section for more information about the test signals. Figure 8-2 shows a diagram of

the input multiplexer on the ADS131M08.

AINnP

AGND

AINnN

DC Test

Signal

To Positive

PGA Input

To Negative

PGA Input

MUXn[1:0] = 00

MUXn[1:0] = 01

MUXn[1:0] = 10

MUXn[1:0] = 11

Figure 8-2. Input Multiplexer

ADS131M08

SBAS950B – OCTOBER 2019 – REVISED FEBRUARY 2021

www.ti.com

Submit Document Feedback

Product Folder Links: ADS131M08

ADS131M08IPBSR Datenblatt(PDF) 20 Page - Texas Instruments

ADS131M08IPBSR Datenblatt(HTML) 20 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datenblatt Download

Link URL