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Электронный компонент: SC4502

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POWER MANAGEMENT
1
www.semtech.com
SC4517A
1.25MHz, 1.5A Step-Down
Switching Regulator
Description
Features
Typical Application Circuit
Applications
Revision: March 8, 2005
The SC4517A is a current mode switching regulator with
an integrated switch, operating at 1.25MHz with separate
sync & enable functions. The integrated switch allows
for cost effective low power solutions (peak switch current
1.5 amps). The sync function allows customers to
synchronize to a faster clock in order to avoid frequency
beating in noise sensitive applications. High frequency
of operation allows for very small passive components.
Current mode operation allows for fast dynamic response
& instantaneous duty cycle adjustment as the input varies
(ideal for CPE applications where the input is a wall plug
power).
The low shutdown current makes it ideal for portable
applications where battery life is important.
The SC4517A is a 1.25MHz switching regulator
synchronizable to a faster frequency from 1.4MHz to
2MHz.
Integrated 1.5 Amp switch
1.25MHz frequency of operation
Current mode controller
Synchronizable to higher frequency up to 2MHz
6A low shutdown current
MSOP-8 and MLPD-8 packages
XDSL modems
CPE equipment
DC-DC point of load applications
Portable equipment
C1
VOUT
D2
D1
R3
C2
L1
Enable
BST
1
IN
2
SW
3
GND
4
EN
5
FB
6
COMP
7
SYNC
8
VIN
C4
C3
SC4517AXX
R1
R2
2
2005 Semtech Corp.
www.semtech.com
POWER MANAGEMENT
SC4517A
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Electrical Characteristics
Note: (1) Minimum pad size.
Unless specified: V
IN
= 12V, V
COMP
= 0.8V, V
BST
= V
IN
+ 5V, EN = Tied to V
IN
, SYNC = 0, SW = open.
T
A
= T
J
= -40C to 125C.
Absolute Maximum Ratings
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. Exposure to Absolute Maximum rated conditions for extended periods of time may
affect device reliability.
3
2005 Semtech Corp.
www.semtech.com
POWER MANAGEMENT
SC4517A
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Electrical Characteristics
(Cont.)
Unless specified: V
IN
= 12V, V
COMP
= 0.8V, V
BST
= V
IN
+ 5V, EN = Tied to V
IN
, SYNC = 0, SW = open.
T
A
= T
J
= -40C to 125C.
4
2005 Semtech Corp.
www.semtech.com
POWER MANAGEMENT
SC4517A
Marking Information
Electrical Characteristics
(Cont.)
R
E
T
E
M
A
R
A
P
L
O
B
M
Y
S
S
N
O
I
T
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5
.
0
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2
k
Notes:
(1) The required minimum input voltage for a regulated output depends on the output voltage and load condition.
(2) Guaranteed by design.
(3) For SYNC applications, please contact factory.
AP50
yyww
APAJ
yyww
Part Number Code (Example: AP50 = 5.0V (50)
yyww = Date Code (Example: 0012)
xxxx = Semtech Lot No. (Example: E901
xxxx 01-1)
yyww = Date Code (Example: 0012)
xxxx = Semtech Lot No. (Example: E901
xxxx 01-1)
Voltage Options (MSOP)
SC4517AIMSXX
Adjustable Options (MSOP)
SC4517AIMS
SC
4517
yyww
Adjustable Options (MLPD)
SC4517AIML
Part Number (Example: 1531)
yyww = Date Code (Example: 0012)
yyww
XX
4517
Part Number (Example 1531)
Part Number Code (Example: XX = 5.0V (50)
yyww = Date Code (Example: 0012)
Voltage Options (MLPD)
SC4517AIMLXX
Unless specified: V
IN
= 12V, V
COMP
= 0.8V, V
BST
= V
IN
+ 5V, EN = Tied to V
IN
, SYNC = 0, SW = open.
T
A
= T
J
= -40C to 125C.
5
2005 Semtech Corp.
www.semtech.com
POWER MANAGEMENT
SC4517A
Pin Configurations
Ordering Information
r
e
b
m
u
N
t
r
a
P
)
3
(
)
2
(
)
1
(
e
g
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c
a
P
T
R
T
X
X
S
M
I
A
7
1
5
4
C
S
8
-
P
O
S
M
T
R
T
S
M
I
A
7
1
5
4
C
S
T
R
T
X
X
L
M
I
A
7
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4
C
S
8
-
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P
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T
R
T
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A
7
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d
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n
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it
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a
v
E
Notes:
(1) Where XX denotes voltage options. Available
voltages are: 1.8V (18), 2.5V (25), 3.3V (33) and 5.0V
(50). Leave blank for adjustable voltage option.
(2) Only available in tape and reel packaging. A reel
contains 2500 devices.
(3) Lead free product. This product is fully WEEE and
RoHS compliant.
1
2
3
4
SYNC
BST
TOP VIEW
(8 Pin MSOP)
5
6
7
8
COMP
IN
FB
SW
EN
GND
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Pin Descriptions
(8 Pin MLPD)
TOP VIEW