SLAS535F September 2007 – October 2018 DAC5652A
The full-scale output current on the DAC5652A can be set two ways: either for each of the two DAC channels independently or for both channels simultaneously. For the independent gain set mode, the GSET pin (pin 42) must be low (that is, connected to AGND). In this mode, two external resistors are required — one RSET connected to the BIASJ_A pin (pin 44) and the other to the BIASJ_B pin (pin 41). In this configuration, the user has the flexibility to set and adjust the full-scale output current for each DAC independently, allowing for the compensation of possible gain mismatches elsewhere within the transmit signal path.
Alternatively, bringing the GSET pin high (that is, connected to AVDD), the DAC5652A switches into the simultaneous gain set mode. Now the full-scale output current of both DAC channels is determined by only one external RSET resistor connected to the BIASJ_A pin. The resistor at the BIASJ_B pin may be removed; however, this is not required since this pin is not functional in this mode and the resistor has no effect on the gain equation.