SLVAFD6 July   2022 TPS564247 , TPS565242

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
  4. 2Analysis of the Floating-Input Pre-bias Output Operation
    1. 2.1 Analysis of FCCM Device
    2. 2.2 Analysis of PSM Device
  5. 3Experimental Verification
    1. 3.1 FCCM device
      1. 3.1.1 Bias Voltage > Target
      2. 3.1.2 Bias Voltage < Target
    2. 3.2 PSM device
      1. 3.2.1 Bias Voltage > Target
      2. 3.2.2 Bias Voltage < Target
  6. 4Summary
  7. 5References

3.2.2 Bias Voltage < Target

In the experiment, the target output voltage is 5 V, bias output is 4.95 V. From the test result in Figure 3-5, the result is basically same as FCCM device in Equation 8.

GUID-20220708-SS0I-ZFDG-03WL-3GXWLK54GFNK-low.png Figure 3-5 Test Waveform of Vbias < Vtarget in PSM Device

In summary, the input voltage of PSM mode device is very closed to the Vbias voltage, both in Vbias<Vtarget and Vbias>Vtarget condition and can operate safely.