1
FN7293
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2003. All Rights Reserved. Elantec is a registered trademark of Elantec Semiconductor, Inc.
All other trademarks mentioned are the property of their respective owners.
EL7558B
Integrated Adjustable 8 Amp
Synchronous Switcher
The EL7558B is an adjustable
synchronous DC:DC switching
regulator optimized for a 5V input and
1.0V-3.8V output. By combining integrated NMOS power
FETS with a HSOP package the EL7558B can supply up to
8A continuous output current without the use of external
power devices or externally attached heat sinks, thereby
minimizing design effort and overall system cost.
On-chip resistorless current sensing is used to achieve
stable, highly efficient, current-mode control. The EL7558B
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 monitors 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 EL7558B is available in the 28-pin HSOP package and
is specified for operation over the -40C to +85C
temperature range.
Pinout
EL7558B
(28-PIN HSOP)
TOP VIEW
Features
EL7558/EL7558A 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
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
Manufactured under U.S. Patents No. 5,723,974 and No. 5,793,126
1
2
3
4
16
15
14
13
5
6
7
12
11
9
8
10
20
19
18
17
24
23
22
21
28
27
26
25
FB1
VSS
VHI
LX
LX
LX
LX
VSSP
VSSP
VSSP
VSSP
VIN
VIN
VDD
COSC
CSLOPE
CREF
TEST
VSSP
VSSP
VCC2DET
OUTEN
OT
VSSP
CP
FB2
C2V
C4
C8
C7
D1
C10
L1
C11
R1
C 6
R5
R6
C3
0.22F
20
2.5H
1mF
220pF
330pF
0.1F
1F
39.2
0.1F
5.1
C9
660F
V
OUT
D2
D3
C 5
1F
R4
R3
100
150
Connect to VSSP for
external feedback
PWRGD
V
IN
V
IN
C3, C4, C5, C6, C7 C8 - ceramic
C5, C11 - ceramic or tantalum
C9 - Sprague 293D337X96R3 2X330F
C10 - Sprague 293D337X96R3 3X330F
L1 - Pulse Engineering, PE-53681
D1 - D4: BAT54S fast diode
1F
C12
D4*
(Optional)
D4 Required for EL7558ACM only
C12 = 1F
Ordering Information
PART NUMBER
PACKAGE
TAPE &
REEL
PKG. NO.
EL7558BCM
28-Pin HSOP
-
MDP0042
EL7558BCM-T13
28-Pin HSOP
13"
MDP0042
Data Sheet
April 27, 2001
FOR
UPD
ATE
D IN
FOR
MAT
ION
SEE
EL7
558D
2
Absolute Maximum Ratings
(T
A
= 25C)
Storage Temperature Range . . . . . . . . . . . . . . . . . .-65C to +150C
Supply (V
IN)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6V
Ambient Operating Temperature . . . . . . . . . . . . . . . .-40C to +85C
Output Pins . . . . . . . . . . . . . . .-0.3V below GND, +0.3V above VDD
Operating Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . 135C
Peak Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9A
CAUTION: Stresses above those listed in "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typical values are for information purposes only. Unless otherwise noted, all tests
are at the specified temperature and are pulsed tests, therefore: T
J
= T
C
= T
A
Electrical Specifications
V
DD
= V
IN
= 5V, C
OSC
= 1nF, C
SLOPE
= 470pF, T
A
= 25C unless otherwise specified.
PARAMETER
DESCRIPTION
CONDITIONS
MIN
TYP
MAX
UNIT
GENERAL
I
DD
V
DD
Supply Current
OUTEN = 4V, F
OSC
= 120kHz
11
25
mA
I
DDOFF
V
DD
Standby Current
OUTEN = 0
0.1
mA
I
VIN
V
IN
No Load Current
OUTEN = 0
3
5
mA
V
OUT1
Output Initial Accuracy
VCC2DET = 4V, IL = 3A
3.450
3.500
3.550
V
V
OUT2
Output Initial Accuracy
VCC2DET = 0V, IL = 3A R3 = 150
,
R4 = 100
2.450
2.500
2.550
V
V
OUTLINE
Output line Regulation
VDD = 5V, 10%
-1
1
%
V
OUTLOAD
Output Load Regulation
0A<I
LOAD
<6A, Relative to IL = 3A.
Continuous Mode of Operation
-1
1
%
R
SHORT
Short Circuit Load Resistance
IL = 6A Prior to Continuous Application
of R
SHORT
. OUTEN Connected to OT.
100
m
I
I MAX
Current Limit
9
A
V
OUTTC
Output Tempco
-40C<T
A
<85C
1
%
T
OT
Over Temperature Threshold
135
C
T
HYS
Over Temperature Hysteresis
40
C
V
PWRGD
Power Good Threshold Relative to
Programmed Output Voltage
VCC2SEL = 4V, V
OUT
= 3.50V
6
10
14
%
V
DDOFF
Minimum VDD for Shutdown
3.15
V
V
DDON
Maximum VDD for Startup
4.15
V
V
HYS
Input Hysteresis
V
HYS
= V
DDON
-V
DDOFF
0.5
V
M
SS
Soft start slope
7
V/ns
D
MAX
Maximum duty cycle
96
%
CONTROLLER - INPUTS
I
PUP
VCC2DET, OUTEN Pull Up Current
VCC2DET, OUTEN = 0
10
14
18
A
I
CSLOPE
Cslope Charging Current
23
28.5
34
A
IFB1
FB1 Input Pull Up Current
2
A
R
OT
Over Temperature Pull Up Resistance
OT = 0V
30
40
50
k
V
IH
VCC2DET, OUTEN Input High
4
V
V
IL
VCC2DET, OUTEN Input Low
.8
V
V
OH
PWGD
Powergood Drive High
ILoad = 1mA
3.5
V
V
OL PWGD
Powergood Drive Low
ILoad = -1mA
1.0
V
EL7558B
3
CONTROLLER - REFERENCE
V
REF
Reference Accuracy
I
REF
= 0
1.247
1.260
1.273
V
V
REFTC
Reference Voltage Tempco
50
ppm/C
V
REFLOAD
Reference Load Regulation
0<I
LOAD
<100A
0.5
0.5
%/C
CONTROLLER - DOUBLER
VC2V
Voltage Doubler Output
V
DD
= 5V, I
LOAD
= 10mA
7.5
8.1
8.7
V
CONTROLLER - OSCILLATOR
F
RAMP
Oscillator Ramp Amplitude
1.2
V
I
OSC CHG
Oscillator Charge Current
0.2V<V
OSC
<1.4V
150
A
I
OSC DIS
Oscillator Discharge Current
0.2V<V
OSC
<1.4V
5
mA
F
OSC
Oscillator initial accuracy
100
120
140
kHz
t
sync
Minimum oscillator sync width
50
ns
POWER - FET
I
LEAK
LX Output Leakage to VSS
LX = 0V
100
A
R
DSON
Composite FET Resistance
18
30
m
R
DSONTC
R
DSON
Tempco
0.1
m
/C
t
BRM
FET break before make delay
10
ns
t
LEB
High side FET minimum on time (LEB)
140
ns
Electrical Specifications
V
DD
= V
IN
= 5V, C
OSC
= 1nF, C
SLOPE
= 470pF, T
A
= 25C unless otherwise specified. (Continued)
PARAMETER
DESCRIPTION
CONDITIONS
MIN
TYP
MAX
UNIT
EL7558B
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