SBOU240 October   2020 OPA455

 

  1.   Trademarks
  2. 1Overview
    1. 1.1 OPA455
    2. 1.2 OPA455EVM
    3. 1.3 Related Documentation
    4. 1.4 Evaluation Module Limitations and Cautions
      1. 1.4.1 High-Voltage Warning
      2. 1.4.2 Electrostatic Discharge Caution
  3. 2Getting Started
    1. 2.1 Power Supplies
    2. 2.2 Jumpers
    3. 2.3 Inputs
    4. 2.4 Outputs
    5. 2.5 Enable or Disable (E/D)
    6. 2.6 Status Flag
      1. 2.6.1 Circuit Protection
  4. 3Application Circuits
    1. 3.1 Improved Howland Current Pump
  5. 4Schematic, PCB Layout, and Bill of Materials
    1. 4.1 EVM Schematic
    2. 4.2 EVM Default Configuration
    3. 4.3 PCB Layout
    4. 4.4 Bill of Materials

2.5 Enable or Disable (E/D)

The OPA455 incorporates a disable feature that can be set using jumpers J3 and J4 on the EVM. The disable is accomplished without disturbing the input signal path, which helps save power in addition to protecting the load. Jumper J3 sets the voltage of the E/D Com pin, which can be set to either the negative rail or GND. The voltage at the E/D Com pin serves as the reference voltage for the E/D pin. J4 sets the voltage at the E/D pin. The device is enabled by floating the E/D pin, or by forcing the E/D pin high using an external voltage. If forcing the E/D pin high, the pin must be pulled at least 2.5 V greater than the E/D Com pin, but should not be pulled any more than 5 V greater than the E/D Com pin. Shorting the E/D pin to the E/D Com pin disables the device.