Precision Analog Reference Voltage from Smaller, Low-cost Mixed Signal Devices | Cypress Semiconductor
Precision Analog Reference Voltage from Smaller, Low-cost Mixed Signal Devices
In certain applications, even though all the signal processing is performed in the digital domain, an analog reference voltage is required. For example, consider a system with an ADC range of 0 to 5 V and input signal value of ±20 mV. This input signal cannot be measured directly with the ADC. Rather, a DC offset has to be added to input signal using an external reference voltage to shift it into the range of ADC. The offset is then compensated for by the firmware after the measurement is taken. With limited analog capability and no analog output pins, creating an output analog voltage reference is a challenge. This article will show how to support an analog voltage reference in small-sized chips with no analog output pins, with the use of only a few external passive components.