5.1 Measurements with Internal Clock

The LDC1614 EVM was programmed so that the LDC1614 was forced into the three different power modes: active, sleep, and shutdown. For each state, the current consumption of the device was measured and compared to the expected values given in the data sheet.

These supply current values are taken while using the internal reference clock. When using an external reference clock, it must be gated to achieve the current consumption specifications in the datasheet. If the external clock is not turned off while the LDC is in sleep or shutdown mode, the power consumption in these modes will be significantly higher. The clocking transitions result in an increase of the LDC input pin leakage currents, which is negligible when compared to the normal mode current, but is significant when added onto the lower power mode currents.