This reference design is designed for high performance data acquisition(DAQ) systems to improve the dynamic range of 20 bit differential input ADCs. Many DAQ systems require the measurement capability at a wide FSR (Full Scale Range) in order to obtain sufficient signal dynamic range. Many earlier reference designs for SAR ADCs have used the THS4551 FDA (fully differential amplifier). However, the THS4551 is limited to a 5.4V maximum supply which is not sufficient for realizing the true 10Vpp differential output (10V FSR) required to maximize the dynamic range of SAR ADCs with a 5V reference. This reference design explores the benefits of a true 10Vpp differential output by implementing TI's new THS4561 FDA which has a maximum supply of 12.6V. You will see that this design was able to achieve superior performance to the previous design (TIDA-01054) while also lowering overall power consumption.
Features
- True 10VPP differential analog front end to 20-Bit ADC
- Modular front-end reference design for high channel count systems that can be repeated