DAC error behavior: An offset error appears as a constant shift of the output transfer curve and therefore causes an incorrect analog output for all input codes. Choose the correct statement.

Introduction / Context:Offset error in a DAC is a fundamental specification. It indicates that the entire transfer function is shifted up or down by a fixed amount relative to the ideal response.

Given Data / Assumptions:

• DAC outputs analog values proportional to digital input codes.
• Offset error is defined as a constant deviation at zero or near-zero code and persists across the range.
• Gain error and linearity errors are separate phenomena.

Concept / Approach:Because offset adds a constant term, y_actual = y_ideal + K, every code experiences the same shift K. Thus every input code is affected.

Step-by-Step Solution:Model ideal transfer: y_ideal = m * code.Include offset: y_actual = m * code + K.Note that K does not depend on code; therefore all codes are shifted equally.

Verification / Alternative check:Datasheets show offset as a single parameter added to the output regardless of the code, corroborated by calibration procedures that subtract a fixed value.

Why Other Options Are Wrong:Limiting to high or low inputs contradicts the definition. “Scattered inputs” describes nonlinearity, not offset. Reference drift changes conditions but offset remains a constant additive error under fixed reference.

Common Pitfalls:Confusing offset (constant) with gain error (slope) and DNL/INL (code-dependent).

Final Answer:for all inputs