SLAS535F September 2007 – October 2018 DAC5652A
The DAC5652A has an on-chip reference circuit which comprises a 1.2-V bandgap reference and two control amplifiers, one for each DAC. The full-scale output current, I(OUTFS), of the DAC5652A is determined by the reference voltage, VREF, and the value of resistor RSET. I(OUTFS) is calculated by:
The reference control amplifier operates as a V-to-I converter producing a reference current, IREF, which is determined by the ratio of VREF and RSET (see Equation 9). The full-scale output current, I(OUTFS), results from multiplying IREF by a fixed factor of 32.
Using the internal reference, a 2-kΩ resistor value results in a full-scale output of approximately 20 mA. Resistors with a tolerance of 1% or better should be considered. Selecting higher values, the output current can be adjusted from 20 mA down to 2 mA. Operating the DAC5652A at lower than 20-mA output currents may be desirable for reasons of reducing the total power consumption, improving the distortion performance, or observing the output compliance voltage limitations for a given load condition.
It is recommended to bypass the EXTIO pin with a ceramic chip capacitor of 0.1 µF or more. The control amplifier is internally compensated and its small signal bandwidth is approximately 300 kHz.