EL7558BC
EL7558BC
Integrated Adjustable 8 Amp Synchronous Switcher
Features
•
EL7558C/EL7558AC pin-
compatible
•
Improved temperature and voltage
ranges
•
8A continuous load current
•
Precision internal 1% reference
•
1.0V to 3.8V output voltage
•
Internal power MOSFETs
•
>90% efficiency
•
Synchronous switching
•
Adjustable slope compensation
•
Over-temperature indicator
•
Pulse-by-pulse current limiting
•
Operates up to 1MHz
•
1.5% typical output accuracy
•
Adjustable oscillator with sync
•
Remote enable/disable
•
Intel P54- and P55-compatible
•
VCC2DET interface
•
Internal soft-start
General Description
The EL7558BC is an adjustable synchronous DC:DC switching regu-
lator optimized for a 5V input and 1.0V-3.8V output. By combining
integrated NMOS power FETS with a HSOP package the EL7558BC
can supply up to 8A continuous output current without the use of
external power devices or externally attached heat sinks, thereby min-
imizing design effort and overall system cost.
On-chip resistorless current sensing is used to achieve stable, highly
efficient, current-mode control. The EL7558BC also incorporates the
VCC2DET function to directly interface with the Intel P54 and P55
microprocessors. Depending on the state of VCC2DET, the output
voltage is internally preset to 3.50V or a user-adjustable voltage using
two external resistors. In both internal and external feedback modes
the active-high PWRGD output indicates when the regulator output is
within ±10% of the programmed voltage. An on-board sensor moni-
tors die temperature (OT) for over-temperature conditions and can be
connected directly to OUTEN to provide automatic thermal shutdown.
Adjustable oscillator frequency and slope compensation allow added
flexibility in overall system design.
The EL7558BC is available in the 28-pin HSOP package and is speci-
fied for operation over the -40°C to +85°C temperature range.
Applications
•
•
•
•
•
•
PC motherboards
Local high power CPU supplies
5V to 1.0V DC:DC conversion
Portable electronics/instruments
P54 and P55 regulators
GTL+ Bus power supply
Connection Diagram
R4
R3
100Ω
150Ω
V
IN
D3
1
FB1
CREF
CSLOPE
COSC
VDD
VIN
VSSP
VIN
VSSP
VSSP
VSSP
VSSP
FB2
28
CP
C2V
VSS
27
C4
0.1µF
2
C5
R1
1µF
D2
D4*
(Optional)
C7
220pF
3
26
C8
R5
330pF
4
5
25
20Ω
R6
VHI
24
C6
6
D1
C11
0.22µF
5.1Ω
LX
LX
LX
LX
VSSP
VSSP
TEST
23
39.2Ω
0.1µF
Ordering Information
Part No
EL7558BCM
EL7558BCM-T13
Package
28-Pin HSOP
28-Pin HSOP
Tape &
Reel
-
13”
7
22
21
20
19
18
17
V
IN
Outline #
MDP0042
MDP0042
C9
660µF
C3
1µF
C12
1µF
8
9
10
11
12
L1
2.5µH
C10
1mF
V
OUT
Connect to VSSP for
external feedback
13
14
VCC2DET
16
PWRGD
OUTEN
OT
15
April 27, 2001
C12 = 1µF
C3, C4, C5, C6, C7 C8 - ceramic
C5, C11 - ceramic or tantalum
C9 - Sprague 293D337X96R3 2X330µF
C10 - Sprague 293D337X96R3 3X330µF
L1 - Pulse Engineering, PE-53681
D1 - D4: BAT54S fast diode
D4 Required for EL7558ACM only
EL7558BC
Manufactured under U.S. Patents No. 5,723,974 and No. 5,793,126
Note:
All information contained in this data sheet has been carefully checked and is believed to be accurate as of the date of publication; however, this data sheet cannot be a “controlled document”. Current revisions, if any, to these
specifications are maintained at the factory and are available upon your request. We recommend checking the revision level before finalization of your design documentation.
© 2001 Elantec Semiconductor, Inc.
ELANTEC [ ELANTEC SEMICONDUCTOR ]
