®
MAT
F OR
N
ED I
DAT
Sheet
6D
Data
EL755
UP
FO R
I
EE
ON S
EL7556B
October 5, 2001
FN7292
Integrated Adjustable 6 Amp
Synchronous Switcher
The EL7556B 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 fused-lead package, the EL7556B can supply
up to 6A continuous output current without the use of
external power devices or discrete 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 EL7556B
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 3.5V 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 EL7556B is available in a 28-pin SO package and is
specified for operation over the full -40°C to +85°C
temperature range.
Features
• EL7556/EL7556A Pin-compatible
• Improved temperature and voltage ranges
• 6A 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
Pinout
EL7556B
(28-PIN SO)
TOP VIEW
R4
R3
100Ω
150Ω
V
IN
D3
• P54 and P55 regulators
• GTL + Bus power supply
1
C4
0.1µF
2
C7
39pF
3
C8
R5
5
5.1Ω
6
7
C9
C12
1µF
C3
1µF
8
9
220pF
4
FB1
CREF
CSLOPE
COSC
VDD
VIN
VSSP
VIN
VSSP
FB2
28
CP
C2V
VSS
27
R1
26
20Ω
25
R6
VHI
24
C6
LX
LX
LX
LX
VSSP
VSSP
TEST
23
0.1µF
22
21
20
19
18
17
L1
2.5µH
C10
1mF
39.2Ω
D1
C11
0.22µF
C5
1µF
D2
D4*
(Optional)
Ordering Information
V
OUT =
1V*(1+R3/R4)
V
IN
660µF
PART NUMBER
EL7556BCM
EL7556BCM-T13
PACKAGE
28-Pin SO
28-Pin SO
TAPE &
REEL
-
13”
PKG. NO.
MDP0027
MDP0027
10
VSSP
11
VSSP
12
VSSP
Connect to VSSP for
external feedback
13
VCC2DET
16
PWRGD
OT
15
14
OUTEN
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 EL7556ACM Only
Manufactured under U.S. Patents No. 5,723,974 and No. 5,793,126
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143
|
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.
EL7556B
Absolute Maximum Ratings
(T
A
= 25°C)
Storage Temperature Range . . . . . . . . . . . . . . . . . .-65°C to +150°C
Supply (V
IN
) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.0V
Ambient Operating Temperature . . . . . . . . . . . . . . . .-40°C to +85°C
Output Pins . . . . . . . . . . . . . . . -0.3V below GND, +0.3V above V
DD
Operating Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . 135°C
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
PARAMETER
GENERAL
I
DD
I
DDOFF
I
VIN
V
OUT1
V
OUT2
V
OUTLINE
V
OUTLOAD
R
SHORT
I
I MAX
V
OUTTC
T
OT
T
HYS
V
PWRGD
V
DDOFF
V
DDON
V
HYS
M
SS
D
MAX
V
DD
= V
IN
= 5V, C
OSC
= 1nF, C
SLOPE
= 470pF, T
A
= 25°C unless otherwise specified.
CONDITIONS
MIN
TYP
MAX
UNIT
DESCRIPTION
V
DD
Supply Current
V
DD
Standby Current
V
IN
No Load Current
Output Initial Accuracy
Output Initial Accuracy
Output line Regulation
Output Load Regulation
Short Circuit Load Resistance
Current Limit
Output Tempco
Over Temperature Threshold
Over Temperature Hysteresis
Power Good Threshold Relative to
Programmed Output Voltage
Minimum V
DD
for Shutdown
Maximum V
DD
for Startup
Input Hysteresis
Soft start slope
Maximum duty cycle
OUTEN = 4V, F
OSC
= 120kHz
OUTEN = 0
OUTEN = 0
VCC2DET = 4V, I
L
= 3A (See Fig. 1)
VCC2DET = 0V, I
L
= 3A R
3
= 150Ω,
R
4
= 100Ω
V
DD
= 5V, ±10%
0A<I
LOAD
<6A, Relative to I
L
= 3A.
Continuous Mode of Operation
IL = 6A, Prior to Continuous Application of
R
SHORT
. OUTEN Connected to OT.
3.450
2.450
-1
-1
11
0.1
3
3.500
2.500
25
mA
mA
5
3.550
2.550
1
1
mA
V
V
%
%
mΩ
A
%
°C
°C
100
9
-40°C<T
A
<85°C
±1
135
40
VCC2SEL = 4V, V
OUT
= 3.50V
±6
3.15
±10
±14
%
V
4.15
V
HYS
= V
DDON
-V
DDOFF
0.5
7
96
V
V
V/mS
%
CONTROLLER - INPUTS
I
PUP
I
CSLOPE
IFB1
R
OT
V
IH
V
IL
V
OH PWGD
V
OL PWGD
VCC2DET, OUTEN Pull Up Current
C
SLOPE
Charging Current
FB1 Input Pull Up Current
Over Temperature Pull Up Resistance
VCC2DET, OUTEN Input High
VCC2DET, OUTEN Input Low
Powergood Drive High
Powergood Drive Low
I
LOAD
= 1mA
I
LOAD
= -1mA
3.5
1.0
OT = 0V
30
4
0.8
VCC2DET, OUTEN = 0
10
23
14
28.5
2
40
50
18
34
µA
µA
µA
kΩ
V
V
V
V
2
Analogue and Mixed Signal
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