SLAAE47A May   2022  – August 2022 DAC11001A , DAC11001B

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
  4. 2DAC Error Sources
    1. 2.1 Offset Error
    2. 2.2 Gain Error
    3. 2.3 Integral Non Linearity (INL)
    4. 2.4 Noise Sources
  5. 3Error Sources from Reference
    1. 3.1 Initial Accuracy
    2. 3.2 Temperature Drift
    3. 3.3 Load Regulation Error
    4. 3.4 Line Regulation Error
    5. 3.5 0.1 - 10 Hz Peak-to-Peak Noise
    6. 3.6 Example Using REF7025
  6. 4Error Sources from Inverting and Non-Inverting Gain Stage
    1. 4.1 Input Offset Voltage Error
    2. 4.2 Input Offset Voltage Drift Error
    3. 4.3 Power Supply Rejection Ratio (PSRR) Error
    4. 4.4 Open Loop Gain Error
    5. 4.5 Resistor Tolerance Error
  7. 5Example Calculation using DAC11001A
  8. 6Error Summary
  9. 7References
  10. 8Revision History

4.3 Power Supply Rejection Ratio (PSRR) Error

Power supply rejection ratio describes how well an amplifier rejects variations in the power supply voltage. PSRR is defined as the shift in offset per volt of shift in power supply, and generally is given in units of micro-volts per volt ( µV/V ). The OPA828 used in this design note has a maximum PSRR of 7 µV/V. Thus, for the OPA828, the power supply can change 1 V with only 7 µV of shift in the offset. Note that this is DC PSRR, where as PSRR in general is frequency dependent. As frequency increases, PSRR decreases. Equation 12 can be used to calculate the offset error due to PSRR for a given power supply ripple voltage.

Equation 12. Offset Voltage Error due to PSRR = Ripple VoltageV10PSRRmindB20 ×106 × Offset Voltage Gain Output VoltageV