EL7640, EL7641, EL7642
The current through MOSFET is limited to 3A peak. This
restricts the maximum output current based on the following
equation:
Where ∆I is peak to peak inductor ripple current, and is set
L
by:
V
D
IN
--------- ----
∆I
=
×
∆I
V
L
L
f
L
IN
×
S
--------
---------
I
=
I
–
LMT
OMAX
2
V
O
where f is the switching frequency.
S
SHUTDOWN
& STARTUP
CONTROL
CLOCK
SLOPE
COMPENSATION
I
I
FB
CURRENT
AMPLIFIER
PWM
LOGIC
LX
REF
BUFFER
I
FB
FBB
GM
AMPLIFIER
I
REF
VOLTAGE
AMPLIFIER
REFERENCE
GENERATOR
PGND
COMP
FIGURE 18. THE BLOCK DIAGRAM OF THE BOOST CONTROLLER
FN7415.1
11
September 26, 2005
INTERSIL [ Intersil ]
