TM
ISL6440
Data Sheet
September 2001
File Number
9040
Advanced PWM and Triple Linear Power
Controller for Gateway Applications
The ISL6440 provides the power control and protection for
four output voltages required by microprocessors used in
high-performance, graphics intensive gateway applications.
The IC integrates a voltage-mode PWM controller and three
linear controllers, as well as the monitoring and protection
functions into a 28-pin SOIC package. The PWM controller
regulates the microprocessor core voltage with a
synchronous-rectified buck converter. The linear controllers
regulate the computer system’s AGP 1.5V or 3.3V bus
power, the 1.5V GTL bus power, and the 1.8V power for the
North/South Bridge core voltage and/or cache memory
circuits. The ISL6440 includes an Intel-compatible, TTL
5-input digital-to-analog converter (DAC) that adjusts the
core PWM output voltage from 1.3V
DC
to 2.05V
DC
in 0.05V
steps and from 2.1V
DC
to 3.5V
DC
in 0.1V increments. The
precision reference and voltage-mode control provide
±1%
static regulation. The AGP bus power linear controller’s
output (V
OUT2
) is user-selectable, through a TTL-compatible
signal applied at the SELECT pin, for levels of 1.5V or 3.3V
with
±3%
accuracy. Based on the status of the FIX pin, the
other two linear regulators provide either fixed output
voltages of 1.5V±3% (V
OUT3
) and 1.8V±3% (V
OUT4
), or
user-adjustable by means of an external resistor divider. All
linear controllers can employ either N-Channel MOSFETs or
bipolar NPNs for the pass transistor.
The ISL6440 monitors all the output voltages. A single
Power Good signal is issued when the core is within
±10%
of
the DAC setting and all other outputs are above their under-
voltage levels. Additional built-in overvoltage protection for
the core output uses the lower MOSFET to prevent output
voltages above 115% of the DAC setting. The PWM
controller’s overcurrent function monitors the output current
by using the voltage drop across the upper MOSFET’s
r
DS(ON)
.
Features
• Provides four regulated voltages
- Microprocessor core, AGP bus, memory, and GTL bus
power
• Drives N-Channel MOSFETs
• Linear regulator drives compatible with both MOSFET and
bipolar series pass transistors
• Fixed or externally resistor-adjustable linear outputs (FIX pin)
• Simple single-loop control design
- Voltage-mode PWM control
• Fast PWM converter transient response
- High-bandwidth error amplifier
- Full 0–100% duty ratio
• Excellent output voltage regulation
- Core PWM output:
±1%
over temperature
- Other outputs:
±3%
over temperature
• TTL-compatible 5-bit DAC microprocessor core output
voltage selection
- Wide range . . . . . . . . . . . . . . . . . . . . . . . . 1.3V–3.5V
DC
• Power-good output voltage monitor
• Overvoltage and overcurrent fault monitors
- Switching regulator does not require extra current
sensing element, uses MOSFET’s r
DS(ON)
• Small converter size
- Constant frequency operation
- 200kHz free-running oscillator; programmable from
50kHz to over 1MHz
- Small external component count
Pinout
ISL6440 (SOIC)
TOP VIEW
DRIVE2 1
FIX 2
VID4 3
28 VCC
27 UGATE
26 PHASE
25 LGATE
24 PGND
23 OCSET
22 VSEN1
21 FB
20 COMP
19 VSEN3
18 DRIVE3
17 GND
16 VAUX
15 DRIVE4
Ordering Information
PART NUMBER
ISL6440CB
ISL6440EVAL1
TEMP.
RANGE (
o
C)
0 to 70
PACKAGE
28 Ld SOIC
PKG.
NO.
M28.3
VID3 4
VID2 5
VID1 6
VID0 7
PGOOD 8
SD 9
VSEN2 10
SELECT 11
SS 12
FAULT/RT 13
VSEN4 14
Evaluation Board
Applications
• Power Regulation for Gateway Processors
• Residential Gateways
• Home Servers
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 trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2001, All Rights Reserved
ISL6440
Absolute Maximum Ratings
Supply Voltage, V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +15V
PGOOD, RT/FAULT, DRIVE, PHASE,
and GATE Voltage . . . . . . . . . . . . . . . GND - 0.3V to V
CC
+ 0.3V
Input, Output or I/O Voltage . . . . . . . . . . . . . . . . . . GND -0.3V to 7V
ESD Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Class 1
Thermal Information
Thermal Resistance (Typical, Note 1)
θ
JA
(
o
C/W)
Operating Conditions
Supply Voltage, V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . +12V
±10%
Ambient Temperature Range . . . . . . . . . . . . . . . . . . . . 0
o
C to 70
o
C
Junction Temperature Range. . . . . . . . . . . . . . . . . . . 0
o
C to 125
o
C
SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . . . . .
70
Maximum Junction Temperature (Plastic Package) . . . . . . . 150
o
C
Maximum Storage Temperature Range . . . . . . . . . . -65
o
C to 150
o
C
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . 300
o
C
(SOIC - Lead Tips Only)
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.
NOTE:
1.
θ
JA
is measured with the component mounted on a low effective thermal conductivity test board in free air. See Tech Brief TB379 for details.
Electrical Specifications
PARAMETER
VCC SUPPLY CURRENT
Nominal Supply Current
POWER-ON RESET
Rising VCC Threshold
Falling VCC Threshold
Rising VAUX Threshold
VAUX Threshold Hysteresis
Rising V
OCSET
Threshold
OSCILLATOR
Free Running Frequency
Total Variation
Ramp Amplitude
Recommended Operating Conditions, Unless Otherwise Noted. Refer to Block and Simplified Power System
Diagrams, and Typical Application Schematic
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
I
CC
UGATE, LGATE, DRIVE2, DRIVE3, and
DRIVE4 Open
-
9
-
mA
V
OCSET
= 4.5V
V
OCSET
= 4.5V
V
OCSET
= 4.5V
V
OCSET
= 4.5V
-
8.2
-
-
-
-
-
2.5
0.5
1.26
10.4
-
-
-
-
V
V
V
V
V
F
OSC
RT = OPEN
6kΩ < RT to GND < 200kΩ
185
-15
-
200
-
1.9
215
+15
-
kHz
%
V
P-P
∆V
OSC
RT = Open
DAC AND BANDGAP REFERENCE
DAC(VID0-VID4) Input Low Voltage
DAC(VID0-VID4) Input High Voltage
DACOUT Voltage Accuracy
Bandgap Reference Voltage
Bandgap Reference Tolerance
LINEAR REGULATORS (OUT2, OUT3, AND OUT4)
Regulation (All Linears)
VSEN2 Regulation Voltage
VSEN2 Regulation Voltage
VSEN3 Regulation Voltage
VSEN4 Regulation Voltage
Undervoltage Level (VSEN/VREG)
Undervoltage Hysteresis (VSEN/VREG)
Output Drive Current (All Linears)
VREG
2
VREG
2
VREG
3
VREG
4
VSEN
UV
VSEN Rising
VSEN Falling
VAUX-V
DRIVE
> 0.6V
SELECT < 0.8V
SELECT > 2.0V
-
-
-
-
-
-
-
20
3
1.5
3.3
1.5
1.8
75
7
40
-
-
-
-
-
-
-
-
%
V
V
V
V
%
%
mA
V
BG
-
2.0
-1.0
-
-2.5
-
-
-
1.265
-
0.8
-
+1.0
-
+2.5
V
V
%
V
%
4
ISL6440
Electrical Specifications
PARAMETER
Recommended Operating Conditions, Unless Otherwise Noted. Refer to Block and Simplified Power System
Diagrams, and Typical Application Schematic
(Continued)
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
SYNCHRONOUS PWM CONTROLLER ERROR AMPLIFIER
DC Gain
Gain-Bandwidth Product
Slew Rate
PWM CONTROLLER GATE DRIVER
UGATE Source
UGATE Sink
LGATE Source
LGATE Sink
PROTECTION
VSEN1 Over-Voltage (VSEN1/DACOUT)
FAULT Sourcing Current
OCSET1 Current Source
Soft-Start Current
POWER GOOD
VSEN1 Upper Threshold
(VSEN1/DACOUT)
VSEN1 Under-Voltage
(VSEN1/DACOUT)
VSEN1 Hysteresis (VSEN1/DACOUT)
PGOOD Voltage Low
V
PGOOD
VSEN1 Rising
VSEN1 Rising
Upper/Lower Threshold
I
PGOOD
= -4mA
108
92
-
-
-
-
2
-
110
94
-
0.8
%
%
%
V
I
OVP
I
OCSET
I
SS
VSEN1 Rising
V
FAULT/RT
= 2.0V
V
OCSET
= 4.5V
DC
-
-
170
-
115
8.5
200
28
120
-
230
-
%
mA
µA
µA
I
UGATE
R
UGATE
I
LGATE
R
LGATE
VCC = 12V, V
UGATE
= 6V
V
GATE-PHASE
= 1V
VCC = 12V, V
LGATE
= 1V
V
LGATE
= 1V
-
-
-
-
1
1.7
1
1.4
-
3.5
-
3.0
A
Ω
A
Ω
GBWP
SR
COMP = 10pF
-
-
-
88
15
6
-
-
-
dB
MHz
V/µs
Typical Performance Curves
100
C
UGATE1
= C
UGATE2
= C
LGATE1
= C
VIN = 5V
1000
RESISTANCE (kΩ)
80
R
T
PULLUP
TO +12V
I
CC
(mA)
60
C = 3600pF
C = 1500pF
VCC = 12V
C = 4800pF
100
40
10
R
T
PULLDOWN TO V
SS
20
C = 660pF
10
100
SWITCHING FREQUENCY (kHz)
1000
0
100
200
300
400
500
600
700
800
SWITCHING FREQUENCY (kHz)
900
1000
FIGURE 1. R
T
RESISTANCE vs FREQUENCY
FIGURE 2. BIAS SUPPLY CURRENT vs FREQUENCY
5
PCB Design
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