Precision dc voltages are a critical component of scientific instrumentation and measurement equipment, automated test equipment, factory automation and control, chemical analysis, and many other high precision applications. The most demanding applications require single digit, part per million temperature drift, subppm linearity, and low, predictable noise performance.
The circuit shown in Figure 1 is a programmable 20-bit voltage source that enables these demanding applications. The output range is −5 V to +5 V with ±1 LSB integral nonlinearity (INL), ±1 LSB differential nonlinearity (DNL), and exceptionally low noise and low drift across the entire output range.
On-board power converters produce the required supply rails from a single voltage supply provided by the development platform board. Low noise, high power supply rejection ratio (PSRR) voltage regulators ensure that the switching noise is minimized. A high precision, high stability, on-board hermetically sealed voltage reference ensures the high precision and accuracy of the 20-bit system.
- +/-5V Output Range
- 20-Bit Signal Generation Control
- On board precision 5V Reference
- All Power Rails Generated Using a Single 3.3V Source
The output of the circuit is a buffered voltage with an option for a remote sense connection to compensate for lead resistance or allow for the insertion of an external power stage, if necessary, providing drive flexibility for the desired end application.