Texas Instruments ADS8402 EVM, ADS8412 EVM manual Signal Conditioning, Analog Input Connector

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Signal Conditioning

2.1 Signal Conditioning

The ADS8402/ADS8412EVM comes installed with the unity gain buffer (U2) wired for single-ended in to differential out configuration. The common-mode voltage is derived from a REF3040 reference IC and is adjustable using a potentiometer (R9). The common-mode voltage pin of the THS4503 is set to 2 V on the evaluation module. A single-ended input signal can be applied at pin connector P1 or via SMA connectors J2 (noninverting input). The buffer circuit can be reconfigured for a unipolar differential input by installing resistor R6 and R8 and removing R1. The inverting leg of the differential signal should be applied to either connector P1 pin 1 or SMA connector J4 (inverting input). See Table 2- 1 for the pinout of the analog connector, P1. See Chapter 6 for the EVM schematic.

Table 2- 1. Analog Input Connector

Description

Signal Name

Connector.Pin#

Signal Name

Description

 

 

 

 

 

 

Inverting input

(-)

P1.1

P1.2

+

Noninverting input

Reserved

N/A

P1.3

P1.4

N/A

Reserved

Reserved

N/A

P1.5

P1.6

N/A

Reserved

Reserved

N/A

P1.7

P1.8

N/A

Reserved

Pin tied to ground

AGND

P1.9

P.10

N/A

Reserved

Pin tied to ground

AGND

P1.11

P1.12

N/A

Reserved

Reserved

N/A

P1.13

P1.14

N/A

Reserved

Pin tied to ground

AGND

P1.15

P1.16

N/A

Reserved

Pin tied to ground

AGND

P1.17

P1.18

N/A

Reserved

Reserved

N/A

P1.19

P1.20

REF+

External reference input

It is recommended the analog input to any SAR-type converter be buffered. The amplifier circuit in Figure 2- 1 is the buffer circuit used on the ADS8402/ADS8412EVM. This circuit consists of the THS4503, a high-speed fully differential amplifier configured as a single-ended in to differential out, unity gain buffer. The circuit shown in Figure 2- 1 was optimized to achieve the ac (i.e., SNR, THD, SFDR, etc.) specifications listed in the ADS8402 and ADS8412 data sheets. The 60-pF and 6800-pF capacitors in the signal path are polypropylene type, manufactured by the WIMA Corporation. Polypropylene capacitors cause the least distortion of the input signal.

2-2

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Contents User’s Guide Important Notice Products ApplicationsEVM Important Notice EVM Warnings and Restrictions Data Sheets Literature Number Read This FirstFCC Warning Contents Figures TablesFeatures Introduction EVM OverviewFeatures IntroductionSignal Conditioning Reference Analog InterfaceSignal Conditioning Analog Input ConnectorDescription Signal Name Connector.Pin# Solder Short Jumper Setting Reference Description Jumper Setting DesignatorReference Page Pinout for Parallel Control Connector P2 Connector.Pin Signal DescriptionDigital Interface Jumper Settings for Decoder Outputs Data Bus Connector P3Pinout for Converter Control Connector J3 Reference Designator Description Jumper SettingsPower Supply Requirements Power Supply Test PointsPower Connector, J1, Pinout Test Point Signal DescriptionPage Using the EVM As a Reference Board As a Prototype BoardAs a Software Test Platform ADS8402/ADS8412EVM BOM, Layout, and Schematic ADS9393EVM Bill of Materials ADS8402/ADS8412EVM Bill Of MaterialsADS8402/ADS8412EVM BOM, Layout, and Schematic ADS8402/ADS8412EVM Layout Top Layer-LayerGround Plane-Layer Power Plane-Layer Bottom Layer-Layer ADS8402/ADS8412EVM Schematic +IN SJP4 TP6 +5VCC

ADS8402 EVM, ADS8412 EVM, ADS8402 specifications

Texas Instruments is renowned for its innovative semiconductor solutions, and the ADS8402 and ADS8412 analog-to-digital converters (ADCs) showcase the company's commitment to precision in data acquisition applications. The ADS8402 is a 16-bit, 2-channel ADC renowned for its high performance and versatility. It operates at data rates up to 1 MSPS (Mega Samples Per Second), making it ideal for a range of applications including industrial automation, high-speed data acquisition systems, and medical instrumentation.

The ADS8402 boasts a differential input architecture that enhances noise immunity and improves measurement accuracy. With features such as integrated voltage reference and a programmable gain amplifier, the device allows for adaptability in handling various signal levels. Its low power consumption further extends its appeal for portable and battery-operated devices. The device comes equipped with an internal clock generator, simplifying system design by reducing external components.

For developers looking to evaluate the performance of the ADS8402, the ADS8402 EVM (Evaluation Module) provides a robust platform. The EVM includes the necessary hardware for quick and convenient testing of the device's capabilities. It features numerous connectivity options, enabling users to interface with a variety of microcontrollers and processors. Benefiting from TI's extensive software support, the EVM allows for easy data visualization and manipulation through compatible software platforms.

On the other hand, the ADS8412 is an advanced 16-bit ADC with a single channel and supports faster sampling rates up to 2 MSPS. It is designed for applications requiring high precision and high throughput. The device features an integrated digital filter that significantly lowers noise and enhances signal integrity. The ADS8412 is particularly well-suited for precision measurement systems in industries such as telecommunications and data acquisition.

The ADS8412 EVM caters to users who wish to explore the capabilities of the ADS8412 with ease. Similar to the ADS8402 EVM, the ADS8412 evaluation module provides structured support for testing with readily available interfaces. This makes it an invaluable tool for engineers and developers looking to integrate high-performance ADCs into their designs.

Both the ADS8402 and ADS8412 ADCs exemplify Texas Instruments' dedication to delivering high-quality, innovative technologies that meet the demands of modern applications. With their combination of precision, speed, and adaptability, these ADCs are excellent choices for engineers seeking reliable data acquisition solutions.
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