Datasheet

1
sw
f p
=
´ ´
C6
R4
Re´
=
o
C sr
C6
R4
TPS57040-Q1
SLVSAP4C –DECEMBER 2010–REVISED OCTOBER 2012 www.ti.com
Use the larger value of Equation 47 and Equation 48 to calculate the C6, to set the compensation pole.
Equation 48 yields 5.9 pF so the nearest standard of 5.6 pF is used.
(47)
(48)
Discontinuous Mode and Eco-mode Boundary
With an input voltage of 34 V, the power supply enters discontinuous mode when the output current is less than
50 mA. The power supply enters Eco-mode when the output current is lower than 30 mA.
The input current draw at no load is 235 μA.
APPLICATION CURVES
Figure 51. Load Transient Figure 52. Startup With VIN
Figure 53. Output Ripple CCM Figure 54. Output Ripple, DCM
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