EL7551_06 Datasheet, PDF (1/9 Pages) Intersil Corporation – Monolithic 1Amp DC:DC Step-down Regulator

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March 21, 2006
EL7551
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 in² 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
Pinout
EL7551
(16-PIN QSOP)
TOP VIEW
• Under voltage lockout
• 16-pin QSOP package
• Pb-free plus anneal available (RoHS compliant)
Applications
C3 C4
0.1µF 270pF
R3
39Ω
C1
10µF
ceramic
V_IN
(4.5V-5.5V)
1 SGND PGND 16
2 COSC VREF 15
3 VDD
FB 14
4 PGND VDRV 13
5 PGND
LX 12
6 VIN
LX 11
7 VIN
VHI 10
8 EN
PGND 9
C5
0.1µF _R2
R1 _2.37kΩ
1kΩ
L1
10µH
C6
0.1µF
C₇
V_O
47µF (3.3V,1A)
• DSP, CPU Core and IO Supplies
• Logic/Bus Supplies
• Portable Equipment
• DC:DC Converter Modules
• GTL + Bus Power Supply
Ordering Information
PART
PART NUMBER MARKING PACKAGE
TAPE & PKG.
REEL DWG. #
EL7551CU
7551CU 16-Pin QSOP - MDP0040
EL7551CU-T7 7551CU 16-Pin QSOP 7” MDP0040
EL7551CU-T13 7551CU 16-Pin QSOP 13” MDP0040
Manufactured under U.S. Patent No. 57,323,974
EL7551CUZ
(See Note)
7551CUZ 16-Pin QSOP - MDP0040
(Pb-free)
EL7551CUZ-T7 7551CUZ 16-Pin QSOP 7” MDP0040
(See Note)
(Pb-free)
EL7551CUZ-T13 7551CUZ 16-Pin QSOP 13” MDP0040
(See Note)
(Pb-free)
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.
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