Datasheet

Input Voltage Ripple
2-9
Test Setup and Results
2.7 Input Voltage Ripple
The TPS54010EVM−067 output voltage ripple is shown in Figure 2−8. The
input voltages PVIN = 2.5 V and VIN = 3.3 V for the TPS54010. Output current
for each device is rated full load of 14 A.
Figure 2−8. Input Voltage Ripple, TPS54010
V
I
(RIPPLE) = 100 mV/div (ac Coupled)
V
(PH)
= 1 V/div
t − Time = 500 ns/div
2.8 Powering Up and Down
The TPS54010EVM-067 start-up waveforms are shown in Figure 2−9 and
Figure 2−10. In Figure 2−9, the top trace shows VIN charging up from 0 V to
3.3 V. When the input voltage reaches the internally set UVLO threshold
voltage, the slow−start sequence begins. After a delay, Vo begins to ramp up
linearly at the externally set slow−start rate toward 1.5 V. In this case, the PVIN
voltage rail is already present at VIN power up. In Figure 2−10, the output
voltage is shown relative to SS/ENA. PVIN and VIN are applied to the EVM
while SS/ENA is held low, disabling the device. When SS/ENA is released, the
slow−start voltage begins to ramp up at the externally set rate. When the
SS/ENA voltage reaches the enable threshold voltage of 1.2 V, the output
voltage begins to ramp up toward its final value of 1.5 V.