Differential op amps are important building blocks in modern analog and mixed signal circuits. Many modern ADCs require differential signals at the inputs. Differential analog signals are also handy to drive signals over a cable. Differential op amps are useful building blocks for creating differential signals. Linear Technology has a large and growing portfolio of differential op amps, covering both low-power precision applications as well as very high-speed applications.
This video shows how to connect differential op amps to convert a single-ended input signal to a differential output. We also take a look at the inner workings of the op amp to explain how the common mode level shifting works. Finally, we show how to use differential op amps to build active filters.
We illustrate the concepts using several examples. The LTC6409 high-speed differential op amp is used in a communications circuit with a pipeline ADC and an RF downconverting mixer. The LTC6362 precision differential op amp is used along with a high-resolution SAR ADC.