JAJU885B April 2017 – January 2023
A negative voltage around –1.8 V is frequently required to bias the digital-to-analog (DAC) data converter in high-performance communications equipment systems, such as base stations and remote radio units. Data converters, such as the DAC38RF80 family of devices, require a negative voltage bias to power the current source array for the current sink output architecture. The 2 A of current provided in this reference design is sufficient to power multiple data converters in a single telecom system, which reduces the number of power supplies and their cost. The wide input voltage range supports many of the different supply voltages available in such systems. This enables the same design to be re-used for different systems which have different input voltages. The low noise and low output ripple enable a clean RF signal without distortion and does not limit the dynamic range of the data converter.
A negative voltage is also required in certain industrial applications, such as test and measurement, to power the same data converters. In addition, this negative voltage is useful for biasing operational amplifiers (op amps). In both applications, an integrated power module shortens the design time and enables a very-small solution size, while the low output noise has a minimal effect on the actual signal.