The paper includes the design of second order sigma-delta modulator. A comparative study between a first order and second order sigma-delta modulator is carried out. The second order is preferred over the first order sigma-delta modulator due to its better signal-to-noise ratio (SNR). The comparative study between the modulators is done in Matlab, the second-order sigma-delta modulator is designed and modelled in Verilog-A and simulated in Cadence SpectreS. The second order sigma-delta modulator provides an enhancement of 27% in SNR as compared to the first order sigma-delta modulator. © 2005 - 2014 JATIT & LLS. All rights reserved.