EL7531
Performance Curves and Waveforms
(Continued)
All waveforms are taken at V
IN
=3.3V, V
O
=1.8V, I
O
=1A with component values shown on page 1 at room ambient temperature, unless otherwise
noted.
V
IN
(2V/DIV)
EN
I
IN
(0.5A/DIV)
V
O
(2V/DIV)
PG
I
IN
(0.5A/DIV)
V
O
(2V/DIV)
PG
200µs/DIV
500µs/DIV
FIGURE 13. START-UP AT I
O
= 1A
FIGURE 14. ENABLE AND SHUT-DOWN
LX
(2V/DIV)
LX
(2V/DIV)
I
L
(0.5A/DIV)
I
L
(0.5A/DIV)
∆V
O
(50mV/DIV)
∆V
O
(10mV/DIV)
2µs/DIV
0.5µs/DIV
FIGURE 15. PFM STEADY-STATE OPERATION WAVEFORM
(I
O
= 100mA)
FIGURE 16. PWM STEADY-STATE OPERATION (I
O
= 1A)
SYNC
(2V/DIV)
LX
(2V/DIV)
I
L
(0.5A/DIV)
SYNC
(2V/DIV)
LX
(2V/DIV)
I
L
(0.5A/DIV)
0.2µs/DIV
20ns/DIV
FIGURE 17. EXTERNAL SYNCHRONIZATION TO 2MHz
FIGURE 18. EXTERNAL SYNCHRONIZATION TO 12MHz
6
FN7428.6
August 5, 2005
INTERSIL [ INTERSIL CORPORATION ]
