TPS54260
SLVSA86 –MARCH 2010
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1
C5 =
2´p ´R4´ fpmod
(46)
A compensation pole can be implemented if desired using an additional capacitor C8 in parallel with the series
combination of R4 and C5. Use the larger value of Equation 47 and Equation 48 to calculate the C8, to set the
compensation pole. C8 is not used for this design example.
Co ´Resr
C8 =
R4
(47)
1
C8 =
R4 ´ fsw ´p
(48)
Discontinuous Mode and Eco Mode Boundary
With an input voltage of 12 V, the power supply enters discontinuous mode when the output current is less than
337 mA. The power supply enters EcoMode when the output current is lower than 5 mA.
The input current draw at no load is 392 mA.
APPLICATION CURVES
Vout = 50 mv / div (ac coupled)
Vin = 10 V / div
Vout = 2 V / div
EN = 2 V / div
Output Current = 1 A / div (Load Step 1.5 A to 2.5 A)
SS/TR = 2 V / div
Time = 200 usec / div
Time = 5 msec / div
Figure 50. Load Transient
Figure 51. Startup With VIN
Vout = 20 mV / div (ac coupled)
Vout = 20 mV / div (ac coupled)
PH = 5 V / div
PH = 5 V / div
Time = 2 usec / div
Time = 2 usec / div
Figure 52. Output Ripple CCM
Figure 53. Output Ripple, DCM
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