Datasheet

SLUU189 − July 2004
14
TPS40009-Based 5-A Converter in Less Than One Square Inch
Figure 9 shows the startup waveforms with an input voltage of 3.3 V and a load of 0.3 Ω. Note that the output
is held low until V
SS
(pin 4) goes above 0.12 V, and then the output comes up smoothly under closed loop
softstart control.
STARTUP WAVEFORM
t − Time − 200 µs/div
1 V/div
500 mV/div
500 mV/div
Figure 9.
Figure 10 shows the transient response for a fast load step from 1 A to 2 A.
TRANSIENT RESPONSE
t − Time − 20 µs/div
50 mV/div
Figure 10.