Clock usage — Which ADC architecture does not require a clock because it performs no sequential timing or bit-by-bit decision process?

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Solve this multiple-choice question and choose the correct option.

Accepted Answer

Introduction / Context: Many ADCs rely on timing sequences (e.g., SAR bit trials, integrating cycles), which require clock signals. However, one architecture works by making all comparisons in parallel with no sequential steps, and thus no conversion clock is strictly required for its core decision.Given Data / Assumptions: We focus on the core conversion mechanism, not on digital interface housekeeping. Parallel comparison against multiple thresholds is used. An encoder converts thermometer code to binary. Concept / Approach: A flash ADC employs a bank of comparators referencing a resistor ladder. The output is determined as soon as comparator outputs settle; no iterative clocked sequence is needed. While practical systems may still clock the readout or pipeline stages, the essential conversion itself is asynchronous.Step-by-Step Solution: Input is applied to all comparators simultaneously.Comparators resolve almost immediately to a thermometer code.Priority encoding produces the binary output. Verification / Alternative check: Architecture diagrams show no SAR logic or integration cycles that would mandate a clock. Why Other Options Are Wrong: Actuator: Not an ADC type.Dual: Likely refers to dual-slope ADCs, which require precise timing.Bipolar: Refers to signal polarity or device technology, not an ADC architecture. Common Pitfalls: Confusing the lack of conversion clock with entirely clockless devices; readout logic may still be clocked. Final Answer: Flash

Clock usage — Which ADC architecture does not require a clock because it performs no sequential timing or bit-by-bit decision process?

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