Hi PrakashRamamoorthy, Welcome to EasyEDA. Basically if it's analogue and/or gate level digital (see **Gates** in the EasyEDA Libs and also: https://easyeda.com/example/Easy_logic_device_simulation_in_V2_3_x_onwards-RaKIG2oJ5) then it can be modelled and simulated in EasyEDA. Unfortunately the LMP90100 is a bit more complex than "an op-amp which have internal buffer and some other special features which gives the output via SPI." It contains input mulitplexing and a 24 bit sigma delta ADC, digital filtering, SPI and GPIO interfaces and a clock oscillator. TI do not supply a spice model for this device and as far as I know neither does anyone else. That is not surprising since this device is way beyond the scope of what any vendor would normally publically release a spice model for. Please see this post to get a bit more insight into why such complex devices are simply impractical to model in spice in general: https://easyeda.com/forum/topic/ADC_modells-7x3lfxP7o Here is what TI offer to support developemnts using this device: http://www.ti.com/product/LMP90100/toolssoftware Here are some resources on SPI: https://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus https://learn.sparkfun.com/tutorials/serial-peripheral-interface-spi If you have further questions, please post back. :)