ADS1294CZXGR datasheet(30/114 Pages) TI2

30 / 114 page

REF

±VREF

Single-Ended Inputs

INP

CM Voltage

Differential Inputs

INP

INN

CM Voltage

REF

±VREF

Common-Mode Voltage (Differential Mode) =

(INP) + (INN)

, Common-Mode Voltage (Single-Ended Mode) = INN

INN = CM Voltage

CM + VREF

CM ± VREF

CM ± 1/2 VREF

CM + 1/2 VREF

Input Range (Differential Mode) = (AINP ± AINN) = 2 VREF

a) Single-Ended Input

b) Differential Input

Device

Common

Voltage

±VREF

+VREF

Device

Peak-to-Peak

REF

Peak-to-Peak

REF

Common

Voltage

ADS1294, ADS1294R, ADS1296, ADS1296R, ADS1298, ADS1298R

SBAS459K – JANUARY 2010 – REVISED AUGUST 2015

www.ti.com

Feature Description (continued)

9.3.1.4 Analog Input

The analog input to the ADS129x is fully differential. Assuming PGA = 1, the differential input (INP – INN) can

span between –VREF to VREF. The absolute range for INP and INN must be between AVSS – 0.3 V and AVDD +

0.3 V. See Table 13 for an explanation of the correlation between the analog input and the digital codes. As

shown in Figure 27 and Figure 28, there are two general methods of driving the analog input of the ADS129x:

single-ended or differential. INP and INN are 180° out-of-phase in the differential input method. When the input is

single-ended, the INN input is held at the common-mode voltage (CM), preferably at midsupply. The INP input

swings around the same common-mode voltage and the peak-to-peak amplitude swings from CM – VREF to CM

+ VREF. When the input is differential, the common-mode is given by (INP + INN) / 2. Both the INP and INN

inputs swing from CM + ½ VREF to CM – ½ VREF. For optimal performance, use the ADS129x devices in a

differential configuration.

Figure 27. Methods of Driving the ADS129x: Single-Ended or Differential

Figure 28. Using the ADS129x in Single-Ended and Differential Input Modes

Submit Documentation Feedback

Product Folder Links: ADS1294 ADS1294R ADS1296 ADS1296R ADS1298 ADS1298R

ADS1294CZXGR Datasheet(PDF) 30 Page - Texas Instruments

ADS1294CZXGR Datasheet(HTML) 30 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

Datasheet Download

Link URL