METHOD AND APPARATUS FOR MEASURING SIGNAL-TO-QUANTIZATION-NOISE RATIO

摘要

Apparatus for determining a signal-to-quantization-noise ratio of a quantization circuit includes a signal generator that generates an input test signal for input to the quantization circuit, circuitry for isolating, from output of the quantization circuit, a signal representing quantization noise, and circuitry for determining a ratio of the output of the quantization circuit to the signal representing quantization noise. The signal generator generates an analog test tone having a frequency, and the circuitry for isolating includes a notch filter filtering that frequency. Alternatively, the circuitry for isolating includes circuitry for generating a digital test signal, and a digital subtractor for subtracting the digital test signal from the output of the quantization circuit. According to another alternative, the circuitry for isolating includes a transformation circuit whose outputs represent a peak of the output of the quantization circuit and a noise floor of the output of the quantization circuit.

主权项

1. Apparatus for determining a signal-to-quantization-noise ratio of a quantization circuit, the apparatus comprising:
a signal generator that generates an input test signal for input to the quantization circuit; circuitry for isolating, from output of the quantization circuit, a signal representing quantization noise; and circuitry for determining a ratio of the output of the quantization circuit to the signal representing quantization noise.