SBAS427D February 2008 – June 2024 AMC1203
PRODUCTION DATA
A differential input signal of 0V ideally produces a stream of ones and zeros that are high 50% of the time. A differential input of 280mV produces a stream of ones and zeros that are high 93.75% of the time. With 16 bits of resolution, that percentage ideally corresponds to code 62440. A differential input of –280mV produces a stream of ones and zeros that are high 6.25% of the time and ideally results in code 4096. The ±280mV range is the specified linear range of the AMC1203. If the input voltage value exceeds ±280mV, the output of the modulator shows increasingly nonlinear behavior as the quantization noise increases. The modulator output clips with a constant stream of zeros with an input ≤ –320mV or with a constant stream of ones with an input ≥ 320mV. Figure 6-3 shows the input voltage versus the output modulator signal.
Calculate the density of ones in the output bitstream with Equation 1 for any input voltage value of VIN, where VIN = (VINP – VINN) :