Blue-Noise Sigma-Delta Modulator: Improving Substrate Noise and Nonlinear Amplifier Gain Effects

— This paper presents a method to reduce the effects of substrate noise and nonlinear amplifier gain on sigma-delta (Σ∆) modulators through the use of blue-noise modulation. In addition to reducing the effects of substrate noise and nonlinear amplifier gain, the proposed architecture also suppresses the effects of integrator opamp non-idealities, such as 1/f noise and DC offset, and DAC DC offset and even-order nonlinearities. The architecture proposed herein is referred to as the blue-noise Σ∆ modulator. An example utilizing a thirdorder blue-noise Σ∆ modulator with a 1-bit quantizer is presented. Additionally, a method to generate the required blue-noise modulation sequence is proposed. Simulation results demonstrate that this architecture achieves an 8.8dB improvement in SNR over the traditional third-order Σ∆ modulator.

• Type: Conference
• Year: 2007
• Where: ISCAS
• Authors: Eric C. Moule, Zeljko Ignjatovic
• Keywords: Blue-noise Σ∆ Modulator, ISCAS 2007, Nonlinear Amplifier Gain, Σ∆ Modulator