System Setup

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The PGA309_Test_Board also has an onboard sensor emulator. The sensor emulator is a circuit that generates the same type of signals generated by a bridge sensor. The sensor emulator circuit is controlled by the PGA309EVM-USB software. Using the sensor emulator allows you to get a deeper understanding of the PGA309EVM-USB software and hardware more quickly. When the capabilities and functions of the PGA309EVM-USB are fully understood, you can connect the real-world sensor to the EVM and perform a full calibration.

Note that calibrations with real-world sensors are time-consuming because devices such as these are normally calibrated at multiple temperatures in an environmental chamber. It is not unusual for temperature calibration to require 12 hours.

2.2PGA309_Test_Board Connections

See Figure 4 for the input connections on the PGA309_Test_Board schematic. T1 provides the power connection for an external bridge sensor. T4 allows connections to each input of the external bridge sensor. T5 allows connection of the external temperature sensor. JMP7, JMP4, JMP5, and JMP6 allow users to select either the onboard sensor emulator or an external sensor. JMP12 allows users to choose between VS or VEXC for the sensor power.

The input is filtered with R3, R4, C14, C15, and C16. Note that C14 is ten times larger then C15, and C16 is used for good ac common-mode rejection. The cutoff frequency of this filter is 40.6Hz (f = 1/(2 p R3 C14)). This input filter is recommended in your final design if you have available board space.

VEXC has a 100pF capacitor and TEMPin has a 1nF capacitor. These components are also recommended in your final design.

Refer to Figure 5 to see the power, reference, and digital connections on the PGA309_Test_Board schematic. T2 provides a connection for an external reference voltage. JMP1 and JMP2 allow users to select between the internal reference, an external reference, or power-supply reference. JMP7 and JMP8 allows users to connect the One-Wire signal to the PRG pin directly or through VOUT.

D2 is a transient voltage suppressor. It is useful in helping to prevent damage in an electrical overstress (EOS) condition. R5 is useful in preventing EOS damage to the output. C6 filters noise at the output. C5 filters the reference output. These components are recommended for your design if PCB space permits. C4 is a decoupling capacitor; it is required in the final design.

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PGA309EVM-USB

SBOU084 –February 2010

 

 

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Copyright © 2010, Texas Instruments Incorporated

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Texas Instruments PGA309EVM-USB manual PGA309TestBoard Connections
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PGA309EVM-USB specifications

The Texas Instruments PGA309EVM-USB is an Evaluation Module designed specifically for the PGA309 Precision Analog Front End (AFE) family. This versatile and powerful device serves various applications in the realm of sensor signal conditioning, particularly for pressure sensors, temperature sensors, and other analog sensors requiring high precision.

One of the main features of the PGA309EVM-USB is its high-performance PGA309 device, which incorporates a programmable gain amplifier (PGA) allowing for flexible signal amplification. The PGA309 has a gain range from 1 to 128, enabling it to adapt to a wide array of sensor types and output levels. This flexibility is crucial for achieving optimal performance in diverse applications.

The module also leverages advanced analog and digital processing technologies, which enhance its capabilities. It integrates an onboard microcontroller, allowing users to easily configure settings, execute control algorithms, and manage data acquisition. The built-in USB interface simplifies the communication with a PC, making it straightforward to control the EVM through intuitive software provided by Texas Instruments.

Another significant characteristic of the PGA309EVM-USB is its highly accurate signal conditioning features, such as offset and gain calibration, which ensure minimized errors and improved measurement reliability. The device supports a variety of digital output configurations, including I2C and SPI, to allow easy integration into different system architectures.

In addition to its robust signal processing core, the PGA309EVM-USB is designed with user-friendly interfaces, making it suitable for both experienced engineers and those new to sensor design. The comprehensive software toolkit offers a graphical user interface (GUI) that enables real-time monitoring and adjustment of parameters, ensuring users can optimize their applications.

Furthermore, the device is designed for functionality in harsh environments, incorporating features to withstand temperature variations and electrical noise. This reliability adds value for applications in industrial automation, automotive systems, and medical devices.

In summary, the Texas Instruments PGA309EVM-USB stands out as a powerful tool for engineers looking to design and prototype high-precision sensor signal conditioning applications. With its programmable gain amplifier, advanced processing capabilities, and user-friendly interfaces, it represents a significant advancement in the field of analog signal processing, allowing for greater flexibility and accuracy in diverse applications.
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