The DAC5652 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 DAC5652 is determined by the reference voltage, V_REF, and the value of resistor R_SET. I_OUTFS can be calculated by:

Equation 9.

The reference control amplifier operates as a V-to-I converter producing a reference current, I_REF, which is determined by the ratio of V_REF and R_SET (see Equation 9). The full-scale output current, I_OUTFS, results from multiplying I_REF 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 DAC5652 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.