ISL88550AIRZ Intersil, ISL88550AIRZ Datasheet

IC PWM CONTROLLER 28TQFN

ISL88550AIRZ

Manufacturer Part Number
ISL88550AIRZ
Description
IC PWM CONTROLLER 28TQFN
Manufacturer
Intersil
Datasheet

Specifications of ISL88550AIRZ

Applications
PWM Controller
Voltage - Input
2 ~ 25 V
Current - Supply
25µA
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
28-TQFN
Rohs Compliant
YES
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Voltage - Supply
-

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
ISL88550AIRZ
Manufacturer:
Intersil
Quantity:
480
Part Number:
ISL88550AIRZ
Manufacturer:
INTERSIL
Quantity:
20 000
Part Number:
ISL88550AIRZ
Manufacturer:
INTERSI
Quantity:
11 316
Part Number:
ISL88550AIRZ-T
Manufacturer:
AMD
Quantity:
2
Part Number:
ISL88550AIRZ-T
Manufacturer:
INTERSIL/PBF
Quantity:
432
Part Number:
ISL88550AIRZ-T
Manufacturer:
INTERSIL
Quantity:
20 000
Company:
Part Number:
ISL88550AIRZ-T
Quantity:
490
Company:
Part Number:
ISL88550AIRZ-T
Quantity:
490
Synchronous Step-Down Controller with
Sourcing and Sinking LDO Regulator
ISL88550A integrates a synchronous buck PWM controller
to generate VDDQ, a sourcing and sinking LDO linear
regulator to generate VTT, and a 10mA reference output
buffer to generate VTTR. The buck controller drives two
external N-Channel MOSFETs to generate output voltages
down to 0.7V from a 2V to 25V input with output currents up
to 15A. The LDO can source up to 2.5A and sink up to -2.0A
continuously. Both the LDO output and the 10mA reference
buffer output can be made to track the REFIN voltage via a
built-in resistive divider. These features make the
ISL88550A ideally suited for DDR memory applications in
desktops, notebooks and graphics cards.
The PWM controller in the ISL88550A uses constant-on-time
PWM architecture with a programmable switching frequency
of up to 600kHz. This control scheme handles wide
input/output voltage ratios with ease and provides 100ns
“instant-on” response to load transients while maintaining
high efficiency and a relatively constant switching frequency.
The ISL88550A offers full programmable UVP/OVP and skip
mode options ideal in portable applications. Skip mode
allows for improved efficiency at lighter loads.
The VTT and VTTR outputs track to VREFIN/2. The high
bandwidth of this LDO regulator allows excellent transient
response without the need for bulk capacitors, thus reducing
the cost and size.
The buck controller and LDO regulators are provided with
independent current limits. Adjustable loss-less fold-back
current limit for the buck regulator is achieved by monitoring
the drain-to-source voltage drop of the low side synchronous
MOSFET. Once overcurrent is removed, the regulator is
allowed to enter soft-start again. This helps minimize power
dissipation during short-circuit condition. Additionally,
overvoltage and undervoltage protection mechanisms are
built in. The ISL88550A allow flexible sequencing and
standby power management using SHDNA#, and STBY#
inputs.
Ordering Information
ISL88550AIRZ
ISL88550AIRZ-T*
*Please refer to TB347 for details on reel specifications.
NOTE: These Intersil Pb-free plastic packaged products employ special Pb-free material sets; molding compounds/die attach materials and 100%
matte tin plate PLUS ANNEAL - e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations.
Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J
STD-020.
PART NUMBER (Note)
®
ISL88 550AIRZ
ISL88 550AIRZ
PART MARKING
1
Data Sheet
TEMP RANGE (°C)
-40 to +85
-40 to +85
1-888-INTERSIL or 1-888-468-3774
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Features
• Pb-Free (RoHS Compliant)
Buck Controller
• Constant-On PWM with 100ns Load-Step Response
• Start-up with Pre-biased Output Voltage
• Up to 95% Efficiency
• 2V to 25V Input Voltage Range
• 2.5V Fixed or 0.7V to 3.5V Adjustable Output
• 200kHz/300kHz/450kHz/600kHz Switching Frequencies
• Programmable Current Limit with Foldback Capability
• 1.7ms Digital Soft-Start and Independent Shutdown
• Overvoltage/Undervoltage Protection Option
• Power-Good Window Comparator
LDO Section
• Fully Integrated VTT and VTTR Capability
• VTT has +2.5A/-2.0A Sourcing/Sinking Capability
• Start-Up with Pre-Biased Output Voltage
• VTT and VTTR Outputs Track VREFIN/2
• VTT and VTTR 1% of VREFIN/2
• Low All-Ceramic Output Capacitor Designs
• 1.0V to 2.8V Input REFIN Range
• Analog Soft-Start Option and Independent Shutdown
• Power-Good Window Comparator
Applications
• DDR, DDR II and DDR III Memory Power Supplies
• Desktop Computers
• Notebooks and Desknotes
• Graphics Cards
• Game Consoles
• Networking and RAID
28 Ld 5×5 TQFN
28 Ld 5×5 TQFN Tape and Reel
All other trademarks mentioned are the property of their respective owners.
April 23, 2008
|
Copyright Intersil Americas Inc. 2005, 2007, 2008. All Rights Reserved
Intersil (and design) is a registered trademark of Intersil Americas Inc.
PACKAGE (Pb-free)
ISL88550A
L28.5x5B
L28.5x5B
PKG. DWG. #
FN6168.3

Related parts for ISL88550AIRZ

ISL88550AIRZ Summary of contents

Page 1

... PART NUMBER (Note) PART MARKING ISL88550AIRZ ISL88 550AIRZ ISL88550AIRZ-T* ISL88 550AIRZ *Please refer to TB347 for details on reel specifications. NOTE: These Intersil Pb-free plastic packaged products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate PLUS ANNEAL - e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations. ...

Page 2

Pinout 2 ISL88550A ISL88550A (28 LD TQFN) TOP VIEW TON 1 OVP/UVP 2 REF 3 4 ILIM POK1 5 6 POK2 7 STBY LGATE 21 20 BOOT ...

Page 3

... DD Junction Temperature Range .-55°C to +150°C + 0.3V DD Operating Temperature Range . . . . . . . . . . . . . . . . .-40°C to +85°C + 0.3V DD Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . -65°C + 150°C Pb-free reflow profile . . . . . . . . . . . . . . . . . . . . . . . . . .see link below http://www.intersil.com/pbfree/Pb-FreeReflow.asp + 0. SHDNA# = STBY# = BOOT = ILIM = 5V, OUT = REFIN = VTTI = 2.5V CONDITIONS FB = OUT FB = GND Rising edge of SHDNA# to full current limit ...

Page 4

Electrical Specifications V = +15V SKIP# = OVP/UVP = GND. PGND1 = PGND2 = PHASE = GND, VTTS = VTT, t +85°C, Unless otherwise specified, parts are 100% tested at +25°C. Temperature limits established by characterization ...

Page 5

Electrical Specifications V = +15V SKIP# = OVP/UVP = GND. PGND1 = PGND2 = PHASE = GND, VTTS = VTT, t +85°C, Unless otherwise specified, parts are 100% tested at +25°C. Temperature limits established by characterization ...

Page 6

Pin Descriptions PIN NAME 1 TON GND, REF OVP/UVP Overvoltage/Undervoltage Protection Control Input. This four-level logic input enables or disables the Overvoltage and/or Undervoltage Protection. The overvoltage ...

Page 7

Pin Descriptions (Continued) PIN NAME 19 PHASE External Inductor Connection. Connect PHASE to the input side of the inductor. PHASE is used for both current limit and the return supply of the UGATE driver. 20 BOOT Boost Flying-Capacitor Connection. Connect ...

Page 8

Typical Operating Characteristics 700 675 650 625 600 I = 12A OUT 575 550 525 500 475 450 OUT 425 400 (V) IN FIGURE 3. SWITCHING FREQUENCY vs INPUT ...

Page 9

Typical Operating Characteristics 0.95 0.94 0.93 0.92 0.91 0.90 0.89 0.88 0.87 0.86 0.85 -0.04 -0.03 -0.02 -0.01 0 LOAD (A) FIGURE 9. VTTR REGULATION vs VTTR LOAD I = 12A 15mA VDDQ VTTR 20µs/DIV FIGURE 11. LOAD ...

Page 10

Typical Operating Characteristics R = 10Ω 20Ω VDDQ VTT 2ms/DIV FIGURE 15. VDDQ START-UP AND SHUTDOWN INTO LIGHT LOAD, DISCHARGE ENABLED 50µs/DIV FIGURE 17. OVERVOLTAGE AND TURN-OFF OF BUCK OUTPUT UVP ENABLE 50µs/DIV FIGURE 19. SHORT CIRCUIT AND ...

Page 11

TON INTREF QUAD LEVEL OVP/UVP DECODER BUCK ON/OFF BLANK SHDNA# BIAS SHUTDOWN ON/OFF DECODER STBY# 0.7 x INTREF VTT ON/OFF VTTR ON/OFF INTREF+10% INTEREF-10% POK1 N FB INTREF/2 + 10% POK2 N INTEREF/2 - 10% 11 ISL88550A VIN t OFF ...

Page 12

Detailed Description The ISL88550A combines a synchronous buck PWM controller, an LDO linear regulator, and a 10mA reference output. The buck controller drives two external N-Channel MOSFETs to deliver load currents up to 15A and generates voltages down to 0.7V ...

Page 13

Specifications” table on page 3 are influenced by resistive losses and by switching delays in the high-side MOSFET. Resistive losses, which include the inductor, both MOSFETs, the output capacitors ESR, and any PC board copper losses in the output ...

Page 14

K-FACTOR TYPICAL K ERROR t SETTING FACTOR (µs) (10%) ON 200kHz 5.0 ± 300kHz 3.3 ± OPEN) ON 450kHz 2.2 ±12 REF) ON 600kHz 1.7 ±12 GND) ON ...

Page 15

1. LOAD(MAX) FIGURE 24. VALLEY CURRENT-LIMIT THRESHOLD POR, UVLO and Soft-Start Internal Power-on reset (POR) occurs when AV above approximately 2V, resetting the fault latch and the soft-start counter, powering up the ...

Page 16

ISL88550A pulls POK1 low. Any fault condition forces POK1 low until the fault latch is cleared by toggling SHDNA# or cycling AV 1V. For logic level output voltages, connect an external pull-up resistor between POK1 and ...

Page 17

OVP/UVP DISCHARGE AV 15Ω internal switch ON DD UGATE/LGATE is low when SHDNA# = low for normal shutdown OPEN 15Ω internal switch ON UGATE/LGATE is low when SHDNA# = low for normal shutdown REF 15Ω internal switch OFF UGATE/LGATE is ...

Page 18

ISL88550A TO ERROR AMPLIFIER FB + 0.1 x REF - (0.2V) FIGURE 25. DUAL-MODE FEEDBACK DECODER Setting the Buck Regulator Output (V Resistive Voltage-Divider at FB The Buck Regulator output voltage can be adjusted from 0.7V to 3.5V using a ...

Page 19

Most inductor manufacturers provide inductors in standard values, such as 1.0µH, 1.5µH, 2.2µH, 3.3µH, etc. Also look for nonstandard values, which can provide a better compromise in LIR across the input voltage range. If using a swinging inductor (where the ...

Page 20

MOSFET turning on, as this would result in shoot through current degrading the efficiency. MOSFETs with a lower ratio have higher immunity to dV/dt For proper ...

Page 21

Setting the Current Limit (Buck) The current-sense method used in the ISL88550A makes use of the ON-resistance ( the low side MOSFET DS(ON "Typical Application Circuit" on page 22). When 2 calculating the current limit, use ...

Page 22

Transient Response (Buck) The inductor ripple current also affects transient response performance, especially at low inductor values allow the inductor current to slew faster, replenishing charge removed from the output filter capacitors by a sudden load ...

Page 23

C3 1µF C9: OPEN AVDD AVDD R2 R3 100k Ω 100k Ω 1.8V C2 10µF PCI-e 1.2V/2A R9 1.21k Ω C4 2µFx10µF R10 4.99k Ω Applications Information Dropout Performance (Buck) The output voltage adjustable range for continuous conduction operation is ...

Page 24

... Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use ...

Page 25

Package Outline Drawing L28.5x5B 28 LEAD THIN QUAD FLAT NO-LEAD PLASTIC PACKAGE Rev 1, 10/07 5.00 6 PIN 1 INDEX AREA (4X) 0.15 TOP VIEW ( 4. 65 TYP ) ( 3. 25) TYPICAL RECOMMENDED LAND PATTERN 25 ISL88550A A ...

Related keywords