28.4.4 Operating Range

The maximum voltage that can be developed across a resistor driven by a current source depends on AV_DD and the other voltage sources in the circuit.

When the resistor is connected to AV_SS, such as seen in Figure 28-2, the maximum voltage that can be developed is approximately AV_DD. However, when the developed voltage is greater than the current source’s internal threshold, the output current is reduced. To prevent this, the maximum developed voltage across R_ESD + R_EXT should be limited to AV_DD – 0.5V (typical), with respect to the output current value.