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Data
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EL7551
March 21, 2006
FN7291.1
Monolithic 1Amp DC:DC Step-down
Regulator
The EL7551 is an integrated, synchronous step-down
regulator with output voltage adjustable from 1.0V to 3.8V. It
is capable of delivering 1A continuous current at up to 95%
efficiency. The EL7551 operates at a constant frequency
pulse width modulation (PWM) mode, making external
synchronization possible. Patented on-chip resistorless
current sensing enables current mode control, which
provides cycle-by-cycle current limiting, over-current
protection, and excellent step load response. The EL7551 is
available in a fused-lead 16-pin QSOP package. With proper
external components, the whole converter fits into a less
than 0.4 in
2
area. The minimal external components and
small size make this EL7551 ideal for desktop and portable
applications.
The EL7551 is specified for operation over the -40°C to
+85°C temperature range.
Features
• Integrated synchronous MOSFETs and current mode
controller
• 1A continuous output current
• Up to 95% efficiency
• 4.5V to 5.5V input voltage
• Adjustable output from 1V to 3.8V
• Cycle-by-cycle current limit
• Precision reference
• ±0.5% load and line regulation
• Adjustable switching frequency to 1.2MHz
• Oscillator synchronization possible
• Internal soft start
• Over temperature protection
• Under voltage lockout
Pinout
EL7551
(16-PIN QSOP)
TOP VIEW
• 16-pin QSOP package
•
Pb-free plus anneal available (RoHS compliant)
Applications
• DSP, CPU Core and IO Supplies
C3
C4
1 SGND
2 COSC
3 VDD
39Ω
4 PGND
C1
10µF
ceramic
V
IN
(4.5V-5.5V)
5 PGND
6 VIN
7 VIN
8 EN
VDRV 13
LX 12
LX 11
VHI 10
PGND 9
C6
0.1µF
PGND 16
C5
VREF 15
0.1µF
FB 14
R2
0.1µF 270pF
R3
• Logic/Bus Supplies
• Portable Equipment
• DC:DC Converter Modules
• GTL + Bus Power Supply
V
O
47µF (3.3V,1A)
C
7
R1 2.37kΩ
1kΩ
L1
10µH
Ordering Information
PART
PART NUMBER MARKING
EL7551CU
EL7551CU-T7
EL7551CU-T13
7551CU
7551CU
7551CU
7551CUZ
7551CUZ
PACKAGE
16-Pin QSOP
16-Pin QSOP
16-Pin QSOP
16-Pin QSOP
(Pb-free)
16-Pin QSOP
(Pb-free)
16-Pin QSOP
(Pb-free)
TAPE &
REEL
-
7”
13”
-
7”
13”
PKG.
DWG. #
MDP0040
MDP0040
MDP0040
MDP0040
MDP0040
MDP0040
Manufactured under U.S. Patent No. 57,323,974
EL7551CUZ
(See Note)
EL7551CUZ-T7
(See Note)
EL7551CUZ-T13 7551CUZ
(See Note)
NOTE: Intersil Pb-free plus anneal products employ special Pb-free material
sets; molding compounds/die attach materials and 100% matte tin plate
termination finish, which are RoHS compliant and compatible with both SnPb
and Pb-free soldering operations. Intersil Pb-free products are MSL classified
at Pb-free peak reflow temperatures that meet or exceed the Pb-free
requirements of IPC/JEDEC J STD-020.
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774
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Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2002, 2003, 2006. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
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