DICC (Delta) Supply-Current Change

If n inputs are at voltages other than 0 V or VCC, the increase in supply current will be n x ICC. The change in supply current (ICC) is tested by applying the specified VCC level, setting one input lower than VCC (for example, VCC – 0.6 V for LVC and ALVC devices) and all other inputs the same as the ICC test, at 0 V or VCC, then measuring the current into the device (see the Figure below). The outputs of the device are open, as well. The DICC specification typically is useful only on CMOS products that are designed to be operated at 5 V or 3.3 V because its purpose is to provide information about the supply-current performance of the CMOS device when driven by 5-V TTL signal levels.

Use the DICC specification as a reference when driving a CMOS device input with a TTL output driver.

The DICC specification also demonstrates the high currents that can occur if VIH and VIL recommended operating conditions are not observed.