SLYY203B September 2021 – April 2023 BQ25125 , LM5123-Q1 , LMR43610 , LMR43610-Q1 , LMR43620 , LMR43620-Q1 , TPS22916 , TPS3840 , TPS62840 , TPS63900 , TPS7A02
Device-level improvements can simplify system-level designs. One such example is the smart enable feature found on the TPS22916, a 60-mΩ, 10-nA leakage load switch. In addition to the ultra-low leakage and IQ performance, this device also offers a smart way to turn the switch on. Usually there is an internal pulldown at the ON pin to ensure that the power switch does not turn on accidentally in case the microcontroller controlling the switch goes into a high impedance state. These pullup and pulldown resistors unfortunately negatively impact system-level IQ.
As shown in Figure 24, the TPS22916, like many nano-IQ products, has smart on or enable circuity that opens the pulldown path after soft start, eliminating the previous always-on IQ and still guaranteeing a known low impedance state when the device is powered off.