Datasheet

Device

0.1 µF1 µF

AVDD AVDD1

0.1 µF1 µF

1.5 V

AVSSAVSS1

DGND

DVDD

+1.5 V

+1.8 V

0.1 µF 1 µF

VCAP1

VCAP2

VCAP3

0.1 µF

VREFP

VREFN

10 µF

VCAP4

1 µF 1 µF

1 µF

1.5 V

22 µF0.1 µF

RESV1

ADS131E04

ADS131E06

ADS131E08

SBAS561A –JUNE 2012–REVISED APRIL 2013

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Connecting the Device to Bipolar (±1.5 V or 1.8 V) Supplies

Figure 48 illustrates the ADS131E0x connected to a bipolar supply. In this example, the analog supplies connect

to the device analog supply (AVDD). This supply is referenced to the device analog return (AVSS), and the

digital supply (DVDD) is referenced to the device digital ground return (DGND).

NOTE: Place the capacitors for supply, reference, and VCAP1 to VCAP4 as close to the package as possible.

Figure 48. Bipolar Supply Operation

Shielding Analog Signal Paths

As with any precision circuit, careful PCB layout ensures the best performance. It is essential to make short,

direct interconnections and avoid stray wiring capacitance—particularly at the analog input pins and AVSS.

These analog input pins are high-impedance and extremely sensitive to extraneous noise. The AVSS pin should

be treated as a sensitive analog signal and connected directly to the supply ground with proper shielding.

Leakage currents between the PCB traces can exceed the ADS131E0x input bias current if shielding is not

implemented. Digital signals should be kept as far as possible from the analog input signals on the PCB.

Product Folder Links: ADS131E04 ADS131E06 ADS131E08