SPRUIC4D January   2017  – June 2022

 

  1.   Piccolo F280049C controlCARD Information Guide
  2. 1Introduction
  3. 2Errata
    1. 2.1 Warnings, Notes, and Errata
  4. 3Getting Familiar With the controlCARD
    1. 3.1 F280049C controlCARD Features
    2. 3.2 F28004x Device Description
    3. 3.3 Assumed Operating Conditions
    4. 3.4 Using the controlCARD
    5. 3.5 Software Development
  5. 4Special Notes
    1. 4.1 XDS100v2 Emulator and SCI/UART Connectivity
    2. 4.2 cJTAG Usage
    3. 4.3 Evaluation of the Programmable Gain Amplifier (PGA)
    4. 4.4 Evaluation of the Analog-to-Digital Converters (ADCs)
    5. 4.5 Evaluation of the Internal DC/DC Converter
  6. 5Hardware References
  7. 6Revision History

4.3 Evaluation of the Programmable Gain Amplifier (PGA)

When evaluating the PGA, the PGA_GND pin must be driven to the ground reference of the PGA_IN signal. The PGA_GND signal may be provided using differential signaling through the HSEC fingers for improved noise immunity, or the PGA_GND pin may be tied to the GND reference of the controlCARD through a 0-Ω resistor (R55 in Figure 4-2) for simplicity.

GUID-8F2D70AF-A4BC-424C-B4B2-AAF6161C2D47-low.gifFigure 4-2 PGA With S7 Open (Output Filter Usable)

The S7 switch bank provides the flexibility to either use the PGA output filter pin (PGAn_OF) for filtering (S7 open in Figure 4-2) or for sampling the PGA input voltage directly by bypassing the internal PGA (S7 closed in Figure 4-3).

GUID-07E6B5D3-3233-4B0B-BDF4-068F2E2E67F0-low.gifFigure 4-3 PGA With S7 Closed (Output Filter Not Usable)
Note:

The S7 closed implementation for PGA6 is different from the other PGAs. Instead of shorting PGA6_OF and PGA6_IN, the PGA6_OF signal may be accessed from the HSEC connector independently of the PGA6_IN signal.

Note:

The PGA RFILTER resistor should never be enabled while the S7 switch is closed. Prolonged exposure to contention between the PGA_IN and PGA_OF pins may result in permanent damage to the internal RFILTER resistor.