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

How to break low IQ barriers

Optimizing IQ requires the resolution of multiple, conflicting design challenges. You must meet all of the critical performance specifications in transient response, noise and accuracy, while reducing IQ by orders of magnitude. Before assessing the trade-offs in performance specifications, you must quantify the IQ and power losses over the entire output load range. For DC/DC switching converters, look at the power efficiency over load current, while for LDOs, look at current efficiency over load current.

As an example, Figure 10 shows the efficiency of TI’s TPS63900https://www.ti.com/product/TPS63900buck-boost converter versus competition. The efficiency for TPS63900 stays above 80% over six decades of load current, starting at 1 µA and hitting a peak efficiency of 96%.

GUID-20210902-SS0I-3WBK-LRR2-KCRGJNSGPMWQ-low.gif Figure 9 Oxide-thinning-induced parasitic low-VT in 2D cross-section (a); and layout view (b).
GUID-20210902-SS0I-ZBGB-9Z3Z-PQP6SLDML8FN-low.gif Figure 10 Efficiency of the TPS63900 (a) and competition (b). (Source: TI and competitor data sheets).