ISL6558.pdf 데이터시트 (총 16 페이지) - 파일 다운로드 ISL6558 데이타시트 다운로드

No Preview Available !

®
Data Sheet
December 2003
ISL6558
FN9027.6
Multi-Purpose Precision Multi-Phase PWM
Controller With Optional Active Voltage
Positioning
The ISL6558 is a multi-phase PWM
TM controller, which in combination with
the HIP6601B, HIP6602B,
HIP6603B, or ISL6605 companion
gate drivers form a complete solution for high-current, high
slew-rate applications. The ISL6558 regulates output
voltage, balances load currents and provides protective
functions for two to four synchronous rectified buck
converter channels.
A novel approach to current sensing is used to reduce
overall solution cost and improve efficiency. The voltage
developed across the lower MOSFET during conduction is
sampled and fed back to the controller. This lossless
current-sensing approach enables the controller to maintain
phase-current balance between the power channels, provide
overcurrent protection, and permit droop compensation.
Optional output voltage “droop” or active voltage positioning
is supported via the DROOP pin. Taking advantage of this
feature reduces the size and cost of the output capacitors
required to support a load transient.
In the event of an overvoltage, the controller monitors and
responds to reduce the risk of damage to load devices.
Undervoltage conditions are indicated through a PGOOD
transition. Overcurrent conditions cause the converter to
shutdown limiting the exposure of load devices. These
integrated monitoring and protection features provide a safe
environment for microprocessors and other advanced low
voltage circuits.
Ordering Information
PART NUMBER TEMP. (oC) PACKAGE PKG. DWG. #
ISL6558CB
0 to 70
16 Ld SOIC
M16.15
ISL6558CB-T
16 Ld SOIC Tape and Reel
ISL6558CR
0 to 70 20 Ld 5x5 QFN L20.5X5
ISL6558CR-T
20 Ld QFN Tape and Reel
ISL6558IB
-40 to 85 16 Ld SOIC
M16.15
ISL6558IB-T
16 Ld SOIC Tape and Reel
ISL6558IR
-40 to 85 20 Ld 5x5 QFN L20.5X5
ISL6558IR-T
20 Ld QFN Tape and Reel
ISL6558EVAL1 Evaluation Platform 1 (SOIC Package,
ISL6558CB + HIP6601BCB)
ISL6558EVAL2 Evaluation Platform 2 (QFN Package,
ISL6558CR + ISL6605CR)
Features
• Multi-Phase Power Conversion
- 2-, 3-, or 4-Phase Operation
• Optional Output Voltage Droop
• Precision Channel-Current Balance
• Lossless Current Sensing
• Precision Reference Voltage
- 0.8V±1.5% Over -40oC - 85oC Range
- 0. 8V± 1.0% Over 0oC - 70oC Range
• Fast Transient Response
• Overcurrent and Overvoltage Protection
• Digital Soft-start
• Power Good Indication
• High Ripple Frequency (80kHz to 1.5MHz)
• QFN Package
- Compliant to JEDEC PUB95 MO-220 QFN-Quad Flat
No Leads-Product Outline
- Near Chip-Scale Package Footprint; Improves PCB
Efficiency and Thinner in Profile
Applications
• Power Supply Control for Microprocessors
• Low Output Voltage, High Current DC-DC Converters
• Voltage Regulator Modules
• Servers and Workstations
• Memory and Accelerated Graphics Port Supplies
• Communication Processor and Personal Computer
Peripherals
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
All other trademarks mentioned are the property of their respective owners.

No Preview Available !

Pinouts
ISL6558 (16 LEAD SOIC)
TOP VIEW
VCC 1
PGOOD 2
COMP 3
DROOP 4
FB 5
VSEN 6
FS/EN 7
GND 8
16 PWM4
15 ISEN4
14 ISEN1
13 PWM1
12 PWM2
11 ISEN2
10 ISEN3
9 PWM3
ISL6558
ISL6558 (20 LEAD 5X5 QFN)
TOP VIEW
20 19 18 17 16
COMP 1
N/C 2
DROOP 3
FB 4
VSEN 5
15 ISEN1
14 PWM1
13 PWM2
12 ISEN2
11 ISEN3
6 7 8 9 10
2

No Preview Available !

Block Diagram
ISL6558
PGOOD
VCC
VSEN
COMP
FB
DROOP
X 0.9
X1.15
-
UV
+
+
OV
-
POWER-ON
RESET (POR)
OV R
LATCH
S
+
-
CLOCK AND
SAWTOOTH
GENERATOR
THREE-STATE
+
PWM
-
SOFT-
START
AND FAULT
LOGIC
+
-
+
PWM
-
0.8V
REFERENCE
+
E/A
-
+
-
+
-
+
PWM
-
+
PWM
-
CURRENT
CORRECTION
PHASE
NUMBER
CHANNEL
DETECTOR
ITOTAL
+
OC
-
+
+
+
+
ITRIP
FS/EN
PWM1
PWM2
PWM3
PWM4
ISEN1
ISEN2
ISEN3
ISEN4
GND
3

No Preview Available !

ISL6558
Functional Pin Description
NOTE: Pin numbers refer to the SOIC package. Check PINOUT
diagrams for QFN pin numbers.
VCC (Pin 1)
Supplies all the power necessary to operate the chip. The IC
starts to operate when the voltage on this pin exceeds the
rising POR threshold and shuts down when the voltage on
this pin drops below the falling POR threshold. Connect this
pin to a 5V (±5%) supply.
PGOOD (Pin 2)
Power good is an open drain output used to indicate the
status of the output voltage. This pin is pulled low when the
converter output voltage is either 10% below or 15% above
the reference voltage.
COMP (Pin 3)
Output of the internal error amplifier. Connect this pin to the
external feedback compensation network.
DROOP (Pin 4)
Output voltage droop or active voltage positioning is
provided by connecting this pin to the FB pin. An internal
current source creates the droop across an external
feedback resistor, RFB. If no droop is desired, this pin MUST
be left open.
FB (Pin 5)
The FB pin is the inverting input of the internal error
amplifier. Connect this pin to the external feedback
compensation network and a resistor divider from the output
for proper control and protection of converter load.
VSEN (Pin 6)
This pin is connected through a resistor divider to the
converter’s output voltage to provide remote sensing. The
undervoltage and overvoltage protection comparators trigger
off this input.
FS/EN (Pin 7)
Connecting a resistor from this pin to ground sets the
internal oscillator frequency. The switching frequency, FSW,
of the converter is adjustable between 80kHz and 1.5MHz.
Pulling this pin to ground disables the converter and three-
states the PWM outputs.
GND (Pin 8)
Bias and reference ground for all controller signals.
PWM1 (Pin 13), PWM2 (Pin 12), PWM3 (Pin 9),
PWM4 (Pin 16)
The controller PWM drive signals are connected to the
individual HIP660x driver PWM input pins. The number of
active channels is determined by the state of PWM3 and
PWM4. If PWM3 is tied to VCC, this indicates to the
controller that two channel operation is desired. In this case,
PWM4 should be left open or tied to VCC. Tying PWM4 to
VCC indicates that three channel operation is desired.
ISEN1 (Pin 14), ISEN2 (Pin 11), ISEN3 (Pin 10),
ISEN4 (Pin 15)
These pins are used to monitor the voltage drop across the
lower MOSFETs for current feedback, output voltage droop
and overcurrent protection. A resistor must be placed in
series with each of these inputs and their respective PHASE
node. The resistor is sized such that the current feedback is
50µA at full load. Sense lines corresponding to inactive
channels should be left open. Inactive channels are those in
which the PWM pin has been tied to VCC or left open.
Thermal Pad (in QFN only)
In the QFN package, the pad underneath the center of the
IC is a thermal substrate. The PCB “thermal land” design
for this exposed die pad should include thermal vias that
drop down and connect to one or more buried copper
plane(s). This combination of vias for vertical heat escape
and buried planes for heat spreading allows the QFN to
achieve its full thermal potential. This pad should be either
grounded or floating, and it should not be connected to
other nodes. Refer to TB389 for design guidelines.
4

No Preview Available !

ISL6558
Typical Application - 3 Phase Converter
VOUT = 0.8V(RFB + ROS)/ROS
RFB
RC +5V
RFB
ROS
ROS
CC
FB DROOP COMP
VSEN
VCC
PGOOD
PWM4
PWM3
PWM2
PWM1
PWM
CONTROL
ISL6558
ISEN4 NC
FS/EN
RT
ISEN3
ISEN2
GND
ISEN1
+5V
PVCC
BOOT
UGATE
VCC
PHASE
PWM
DRIVER
HIP6601B
LGATE
GND
+5V
PVCC
BOOT
UGATE
VCC
PWM
PHASE
DRIVER
HIP6601B
LGATE
GND
+5V
PVCC
BOOT
UGATE
VCC
PWM
DRIVER
HIP6601B
PHASE
LGATE
GND
+12V
RISEN3
+12V
VOUT
RISEN2
+12V
RISEN1
5