POWER MANAGEMENT
1
www.semtech.com
SC4614
500kHz Voltage Mode PWM Controller
Features
Applications
August 31, 2005
Typical Application Circuit
Description
The SC4614 is a high-speed, voltage mode PWM con-
troller that provides the control and protection features
necessary for a synchronous buck converter.
The SC4614 is designed to directly drive the top and
bottom MOSFETs of the buck converter. It allows the con-
verter to operate at 500kHz switching frequency with
4V to 18V power rail and as low as 0.5V output. It uses
an internal 8.2V supply as the gate drive voltage for mini-
mum driver power loss and MOSFET switching loss.
The SC4614 features soft-start, supply power under volt-
age lockout, and hiccup mode over current protection.
The SC4614 monitors the output current by using the
Rdson of the bottom MOSFET in the buck converter that
eliminates the need for a current sensing resistor. The
SC4614 is offered in a MSOP-10 package.
u
500kHz switching frequency
u
4V to 18V power rails
u
0.5V voltage reference for programmable output
voltages
u
Internal LDO for optimum gate drive voltage
u
1.5A gate drive current
u
Adaptive non-overlapping gate drives provide
shoot-through protection for MOSFETs
u
Internal soft start
u
Hiccup mode short circuit protection
u
Power rail under voltage lockout
u
MSOP-10 package
u
Embedded, low cost, high efficiency converters
u
Point of load power supplies
u
Set top box power supplies
u
PDP/TFT TVs
u
Consumer electronics
12V IN
1
2
1.5V OUT
SC4614
1
2
3
4
7
8
9
10
5
6
BST
OCS
COMP
FB
VCC
DL
PN
DH
GND
DRV
+
+
2
2005 Semtech Corp.
www.semtech.com
POWER MANAGEMENT
SC4614
Absolute Maximum Ratings
Electrical Characteristics
Unless specified: V
CC
= 5V to 18V; V
FB
= V
O
; V
BST
- V
PN
= 5V to 8.2V; T
A
= -40 to 85C
Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters specified
in the Electrical Characteristics section is not implied.
r
e
t
e
m
a
r
a
P
l
o
b
m
y
S
m
u
m
i
x
a
M
s
t
i
n
U
e
g
a
tl
o
V
y
l
p
p
u
S
t
u
p
n
I
V
CC
0
2
V
D
N
G
o
t
T
S
B
V
T
S
B
0
4
V
N
P
o
t
T
S
B
V
N
P
_
T
S
B
0
1
V
D
N
G
o
t
N
P
V
N
P
0
3
o
t
1
-
V
t
(
e
s
l
u
P
e
v
it
a
g
e
N
D
N
G
o
t
N
P
e
s
l
u
p
)
s
n
0
2
<
V
E
S
L
U
P
_
N
P
5
-
V
D
N
G
o
t
L
D
V
L
D
o
t
1
-
0
1
+
V
t
(
e
s
l
u
P
e
v
it
a
g
e
N
D
N
G
o
t
L
D
e
s
l
u
p
)
s
n
0
2
<
V
E
S
L
U
P
_
L
D
3
-
V
N
P
o
t
H
D
V
N
P
_
H
D
o
t
1
-
0
1
+
V
t
(
e
s
l
u
P
e
v
it
a
g
e
N
N
P
o
t
H
D
e
s
l
u
p
)
s
n
0
2
<
V
E
S
L
U
P
_
H
D
3
-
V
D
N
G
o
t
V
R
D
V
V
R
D
0
1
V
e
g
n
a
R
e
r
u
t
a
r
e
p
m
e
T
t
n
e
i
b
m
A
g
n
it
a
r
e
p
O
T
A
5
8
o
t
0
4
-
C
e
r
u
t
a
r
e
p
m
e
T
n
o
it
c
n
u
J
g
n
it
a
r
e
p
O
T
J
5
2
1
o
t
0
4
-
C
t
n
e
i
b
m
A
o
t
n
o
it
c
n
u
J
e
c
n
a
t
s
i
s
e
R
l
a
m
r
e
h
T
A
J
0
0
1
W
/
C
e
s
a
C
o
t
n
o
it
c
n
u
J
e
c
n
a
t
s
i
s
e
R
l
a
m
r
e
h
T
C
J
2
3
W
/
C
s
0
1
)
g
n
i
r
e
d
l
o
S
(
e
r
u
t
a
r
e
p
m
e
T
d
a
e
L
T
D
A
E
L
0
0
3
C
e
r
u
t
a
r
e
p
m
e
T
e
g
a
r
o
t
S
T
G
T
S
0
5
1
o
t
5
6
-
C
r
e
t
e
m
a
r
a
P
l
o
b
m
y
S
s
n
o
i
t
i
d
n
o
C
n
i
M
p
y
T
x
a
M
s
t
i
n
U
l
a
r
e
n
e
G
e
g
a
tl
o
V
y
l
p
p
u
S
C
C
V
V
CC
4
8
1
V
t
n
e
r
r
u
C
t
n
e
c
s
e
i
u
Q
C
C
V
I
C
C
V
Q
V
CC
V
,
V
2
1
=
BST
V
-
PN
V
2
.
8
=
5
7
A
m
t
u
o
k
c
o
L
e
g
a
tl
o
V
r
e
d
n
U
C
C
V
V
U
C
C
V
V
T
S
Y
H
V
m
0
0
1
=
4
V
e
g
a
tl
o
V
y
l
p
p
u
S
N
P
o
t
T
S
B
V
N
P
_
T
S
B
4
0
1
V
t
n
e
r
r
u
C
t
n
e
c
s
e
i
u
Q
T
S
B
I
T
S
B
Q
V
CC
V
,
V
2
1
=
BST
V
-
PN
V
2
.
8
=
3
A
m
O
D
L
l
a
n
r
e
t
n
I
t
u
p
t
u
O
O
D
L
V
V
R
D
V
<
V
6
.
8
C
C
V
8
1
<
2
.
8
V
e
g
a
tl
o
V
t
u
o
p
o
r
D
V
P
O
R
D
V
<
V
4
C
C
V
6
.
8
<
4
.
0
V
3
2005 Semtech Corp.
www.semtech.com
POWER MANAGEMENT
SC4614
Notes:
(1) This device is ESD sensitive. Use of standard ESD handling precautions is required.
(2) Guaranteed by design, not tested in production.
Electrical Characteristics
Unless specified: V
CC
= 5V to 18V; V
FB
= V
O
; V
BST
- V
PN
= 5V to 8.2V; T
A
= -40 to 85C
r
e
t
e
m
a
r
a
P
l
o
b
m
y
S
s
n
o
i
t
i
d
n
o
C
n
i
M
p
y
T
x
a
M
s
t
i
n
U
r
o
t
a
l
u
g
e
R
g
n
i
h
c
t
i
w
S
e
g
a
tl
o
V
e
c
n
e
r
e
f
e
R
V
F
E
R
T
A
V
,
C
5
2
=
CC
V
2
1
=
5
9
4
.
0
0
0
5
.
0
5
0
5
.
0
V
n
o
it
a
l
u
g
e
R
d
a
o
L
I
O
A
4
o
t
2
.
0
=
4
.
0
%
n
o
it
a
l
u
g
e
R
e
n
i
L
V
CC
V
4
1
o
t
V
0
1
=
4
.
0
%
y
c
n
e
u
q
e
r
F
g
n
it
a
r
e
p
O
F
S
0
0
4
0
0
5
0
0
6
z
H
k
e
d
u
ti
l
p
m
A
p
m
a
R
)
2
(
V
m
8
.
0
V
e
l
c
y
C
y
t
u
D
m
u
m
i
x
a
M
)
2
(
D
X
A
M
7
9
%
e
m
i
T
g
n
il
l
a
F
/
g
n
i
s
i
R
H
D
t
H
D
_
C
R
S
C
t
a
g
n
i
w
S
V
6
L
F
n
3
.
3
=
V
T
S
B
V
-
N
P
V
2
.
8
=
1
4
s
n
t
H
D
_
K
N
I
S
7
2
e
m
i
T
g
n
il
l
a
F
/
g
n
i
s
i
R
L
D
t
L
D
_
C
R
S
C
t
a
g
n
i
w
S
V
6
L
F
n
3
.
3
=
V
V
R
D
V
2
.
8
=
9
2
s
n
t
L
D
_
K
N
I
S
2
4
e
m
i
T
g
n
i
p
p
a
lr
e
v
o
n
o
N
L
D
,
H
D
0
3
s
n
e
m
i
T
t
r
a
t
S
tf
o
S
T
A
V
,
C
5
2
=
CC
V
2
1
=
5
.
1
s
m
r
e
i
f
il
p
m
A
r
o
r
r
E
e
g
a
t
l
o
V
e
g
a
tl
o
V
t
e
s
ff
O
t
u
p
n
I
)
2
(
2
V
m
t
n
e
r
r
u
C
t
e
s
ff
O
t
u
p
n
I
)
2
(
0
4
A
n
n
i
a
G
p
o
o
L
n
e
p
O
)
2
(
0
8
B
d
h
t
d
i
w
d
n
a
B
n
i
a
G
y
ti
n
U
)
2
(
0
1
z
H
M
t
n
e
r
r
u
C
e
c
r
u
o
S
t
u
p
t
u
O
9
.
0
A
m
t
n
e
r
r
u
C
k
n
i
S
t
u
p
t
u
O
9
.
0
A
m
e
t
a
R
w
e
l
S
)
2
(
d
a
o
L
F
p
0
0
5
=
L
C
r
o
F
2
.
1
s
u
/
V
4
2005 Semtech Corp.
www.semtech.com
POWER MANAGEMENT
SC4614
Pin Configuration
Ordering Information
Pin Descriptions
Note:
(1) Only available in tape and reel packaging. A reel
contains 2500 devices.
(2) Lead free product. This product is fully WEEE and
RoHS compliant.
s
r
e
b
m
u
N
t
r
a
P
e
g
a
k
c
a
P
T
R
T
S
M
4
1
6
4
C
S
)
2
(
)
1
(
0
1
-
P
O
S
M
B
V
E
4
1
6
4
C
S
#
n
i
P
e
m
a
N
n
i
P
n
o
i
t
c
n
u
F
n
i
P
1
T
S
B
.
s
a
i
b
e
v
ir
d
e
t
a
g
p
o
t
r
o
f
t
u
p
n
i
t
s
o
o
B
2
S
C
O
m
a
r
g
o
r
p
o
t
d
n
u
o
r
g
o
t
d
n
a
n
i
p
V
R
D
o
t
n
i
p
s
i
h
t
m
o
r
f
s
r
o
t
s
i
s
e
r
t
c
e
n
n
o
C
.
g
n
it
t
e
s
ti
m
il
t
n
e
r
r
u
C
.
s
li
a
t
e
d
r
o
f
n
o
it
c
e
S
n
o
it
a
m
r
o
f
n
I
s
n
o
it
a
c
il
p
p
A
o
t
r
e
f
e
R
.t
n
e
r
r
u
c
d
a
o
l
f
o
t
n
i
o
p
p
ir
t
e
h
t
3
P
M
O
C
.
n
o
it
a
s
n
e
p
m
o
c
r
o
f
t
u
p
t
u
o
r
e
if
il
p
m
a
r
o
r
r
E
4
B
F
.r
e
t
r
e
v
n
o
c
k
c
u
b
s
u
o
n
o
r
h
c
y
s
f
o
k
c
a
b
d
e
e
f
e
g
a
tl
o
V
5
D
N
G
.
d
n
u
o
r
g
p
i
h
C
6
V
R
D
r
o
f
d
n
u
o
r
g
o
t
n
i
p
s
i
h
t
m
o
r
f
r
o
ti
s
a
p
a
c
c
i
m
a
r
e
c
F
u
1
a
t
c
e
n
n
o
C
.t
u
p
t
u
o
O
D
L
l
a
n
r
e
t
n
I
.
s
r
e
v
ir
d
e
t
a
g
g
n
i
d
u
l
c
n
i
,
s
a
i
b
p
i
h
c
r
o
f
d
e
s
u
s
i
e
g
a
tl
o
v
s
i
h
T
.
g
n
il
p
u
o
c
e
d
7
C
C
V
.
y
l
p
p
u
s
r
e
w
o
p
t
u
p
n
i
p
i
h
C
8
L
D
.
T
E
F
S
O
M
m
o
tt
o
b
r
o
f
e
v
ir
d
e
t
a
G
9
N
P
.
n
i
a
r
d
T
E
F
S
O
M
-
N
m
o
tt
o
b
o
t
n
i
p
s
i
h
t
t
c
e
n
n
o
C
.
e
d
o
n
e
s
a
h
P
0
1
H
D
.
T
E
F
S
O
M
p
o
t
r
o
f
e
v
ir
d
e
t
a
G
PN
GND
DL
DRV
VCC
BST
FB
DH
1
PDF 
ZIP