SLYY203B September   2021  – April 2023 BQ25125 , LM5123-Q1 , LMR43610 , LMR43610-Q1 , LMR43620 , LMR43620-Q1 , TPS22916 , TPS3840 , TPS62840 , TPS63900 , TPS7A02

 

  1.   1
  2.   Overview
  3.   At a glance
  4.   Contributors to IQ
  5.   Why low IQ creates new challenges
    1.     Transient response
    2.     Ripple
    3.     Noise
    4.     Die size and solution area
    5.     Leakage and subthreshold operation
  6.   How to break low IQ barriers
    1.     Addressing transient response issues
    2.     Addressing switching-noise issues
    3.     Addressing other noise issues
    4.     Addressing die size and solution area issues
    5.     Addressing leakage and subthreshold operation issues
  7.   Electrical Characteristics
    1.     18
    2.     Avoiding potential system pitfalls in a low-IQ designs
    3.     Achieving low IQ, but not losing flexibility
    4.     Reducing external component count to lower IQ in automotive applications automotive applications
    5.     Smart on or enable features supporting low-IQ at the Smart on or enable features supporting low-IQ at the system level
  8.   Conclusion
  9.   Key product categories for low IQ

Smart on or enable features supporting low-IQ at the Smart on or enable features supporting low-IQ at the system level

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.

GUID-20210902-SS0I-9H1C-DWBS-KLRJF3HVTG1W-low.gif Figure 24 Smart-enabled circuit guaranteeing low impedance for the ON pin when device is turned off.