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LM3489, LM3489-Q1
SNVS443C – MAY 2006 – REVISED DECEMBER 2016
LM3489x Hysteretic PFET Buck Controller With Enable Pin
1 Features
3 Description
•
•
The LM3489 device is a high-efficiency PFET
switching regulator controller that can be used to
quickly and easily develop a small, cost-effective,
switching buck regulator for a wide range of
applications. The hysteretic control architecture
provides for simple design without any control loop
stability concerns using a wide variety of external
components. The PFET architecture also allows for
low component count as well as ultra-low dropout,
100% duty cycle operation. Another benefit is high
efficiency operation at light loads without an increase
in output ripple. A dedicated enable pin provides a
shutdown mode drawing only 7 µA. Leaving the
enable pin unconnected defaults to on.
1
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•
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Qualified for Automotive Parts
AEC-Q100 Qualified With the Following Results:
– Device Temperature Grade 1: –40°C to 125°C
Ambient Operating Temperature Range
– Device HBM ESD Classification Level 2
– Device CDM ESD Classification Level C5
Easy-to-Use Control Methodology
No Control Loop Compensation Required
Wide 4.5-V to 35-V Input Range
1.239 V to VIN Adjustable Output Range
High Efficiency: 93%
±1.3% (±2% Over Temperature) Internal
Reference
100% Duty Cycle Operation
Maximum Operation Frequency > 1 MHz
Current Limit Protection
Dedicated Enable Pin (on if Unconnected)
Shutdown Mode Draws Only 7-µA Supply Current
8-Pin VSSOP Package
Current limit protection can be implemented by
measuring the voltage across the PFET’s RDS(ON),
thus eliminating the need for a sense resistor. A
sense resistor may be used to improve current limit
accuracy if desired. The cycle-by-cycle current limit
can be adjusted with a single resistor, ensuring safe
operation over a range of output currents.
Device Information(1)
PART NUMBER
PACKAGE
BODY SIZE (NOM)
2 Applications
LM3489
LM3489-Q1
•
•
•
•
•
•
•
•
•
•
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Set-Top Boxes
DSL or Cable Modems
PC/IA
Auto PCs
TFT Monitors
Battery-Powered Portable Applications
Distributed Power Systems
Always-On Power
High-Power LED Drivers
Automotive
VSSOP (8)
3.00 mm × 3.00 mm
Typical Application Circuit
L
C ADJ R ADJ
VIN
V OUT
Q1
RIS
7
D1
1
PGATE
+
5
CIN1
8
3
CIN2
ISENSE
ADJ
VIN
EN
LM3489
FB
GND
PGND
Cff
R1
+
C OUT
4
2
R2
6
Copyright © 2016, Texas Instruments Incorporated
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
LM3489, LM3489-Q1
SNVS443C – MAY 2006 – REVISED DECEMBER 2016
www.ti.com
Table of Contents
1
2
3
4
5
6
7
Features ..................................................................
Applications ...........................................................
Description .............................................................
Revision History.....................................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
2
3
4
6.1
6.2
6.3
6.4
6.5
6.6
6.7
4
4
4
4
5
5
6
Absolute Maximum Ratings ......................................
ESD Ratings: LM3489 ..............................................
ESD Ratings: LM3489-Q1 ........................................
Recommended Operating Conditions.......................
Thermal Information ..................................................
Electrical Characteristics...........................................
Typical Characteristics ..............................................
Detailed Description .............................................. 9
7.1 Overview ................................................................... 9
7.2 Functional Block Diagram ......................................... 9
7.3 Feature Description................................................... 9
7.4 Device Functional Mode ......................................... 14
8
Application and Implementation ........................ 15
8.1 Application Information............................................ 15
8.2 Typical Application .................................................. 15
9 Power Supply Recommendations...................... 19
10 Layout................................................................... 19
10.1 Layout Guidelines ................................................. 19
10.2 Layout Examples................................................... 19
11 Device and Documentation Support ................. 20
11.1
11.2
11.3
11.4
11.5
11.6
Related Links ........................................................
Receiving Notification of Documentation Updates
Community Resources..........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
20
20
20
20
20
20
12 Mechanical, Packaging, and Orderable
Information ........................................................... 20
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision B (February 2013) to Revision C
Page
•
Added ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation
section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and
Mechanical, Packaging, and Orderable Information section .................................................................................................. 1
•
Added AEC-Q100 Qualification bullets to Features ............................................................................................................... 1
•
Deleted Lead temperature (Vapor phase and Infrared maximums) ....................................................................................... 4
•
Added Thermal Information table ........................................................................................................................................... 5
Changes from Revision A (February 2013) to Revision B
•
2
Page
Changed layout of National Semiconductor Data Sheet to TI format .................................................................................... 1
Submit Documentation Feedback
Copyright © 2006–2016, Texas Instruments Incorporated
Product Folder Links: LM3489 LM3489-Q1
LM3489, LM3489-Q1
www.ti.com
SNVS443C – MAY 2006 – REVISED DECEMBER 2016
5 Pin Configuration and Functions
DGK Package
8-Pin VSSOP
Top View
ISENSE
1
8
VIN
GND
2
7
PGATE
EN
3
6
PGND
FB
4
5
ADJ
Not to scale
Pin Functions
PIN
NO.
NAME
I/O
DESCRIPTION
The current sense input pin. This pin must be connected to the PFET drain terminal directly or
through a series resistor up to 600 Ω for 28 V > VIN > 35 V.
1
ISENSE
I
2
GND
—
3
EN
I
Enable pin. Connect EN pin to ground to shutdown the part or float to enable operation (Internally
pulled high). This pin can also be used to perform UVLO function.
4
FB
I
The feedback input. Connect the FB to a resistor voltage divider between the output and GND for an
adjustable output voltage.
5
ADJ
I
Current limit threshold adjustment. Connected to an internal 5.5-µA current source. A resistor is
connected between this pin and VIN. The voltage across this resistor is compared with the ISENSE
pin voltage to determine if an overcurrent condition has occurred.
6
PGND
—
Power ground
7
PGATE
O
Gate drive output for the external PFET. PGATE swings between VIN and VIN 5-V.
8
VIN
I
Power supply input pin
Signal ground
Copyright © 2006–2016, Texas Instruments Incorporated
Product Folder Links: LM3489 LM3489-Q1
Submit Documentation Feedback
3
LM3489, LM3489-Q1
SNVS443C – MAY 2006 – REVISED DECEMBER 2016
www.ti.com
6 Specifications
6.1 Absolute Maximum Ratings
See
(1)
.
MIN
MAX
UNIT
VIN voltage
–0.3
36
V
PGATE voltage
–0.3
36
V
FB voltage
–0.3
5
V
–1
36
ISENSE voltage
ADJ voltage
EN voltage
V
–1 ( 28 V) an increased negative SW transient
spike at the switch node can lead to an increase in the current limit threshold due to the formation of the parasitic
NPN connection between the ISENSE pin, the internal substrate and the ADJ pin . To avoid this issue, a
Schottky catch diode with lower forward voltage drop must be used. In addition to that, a resistor must be placed
between the ISENSE pin and the external switch node. A resistor value in the range of 220 Ω to 600 Ω is
recommended.
10 Layout
10.1 Layout Guidelines
The PCB layout is very important in all switching regulator designs. Poor layout can cause switching noise into
the feedback signal and generate EMI problems. For minimal inductance, the wires indicated by heavy lines in
schematic diagram must be as wide and short as possible. Keep the ground pin of the input capacitor as close
as possible to the anode of the catch diode. This path carries a large AC current. The switching node, the node
with the diode cathode, inductor and FET drain must be kept short. This node is one of the main sources for
radiated EMI since it sees a large AC voltage at the switching frequency. It is always a good practice to use a
ground plane in the design, particularly for high-current applications.
The two ground pins, PGND and GND, must be connected by as short a trace as possible. They can be
connected underneath the device. These pins are resistively connected internally by approximately 50 Ω. The
ground pins must be tied to the ground plane, or to a large ground trace in close proximity to both the FB divider
and COUT grounds.
The gate pin of the external PFET must be placed close to the PGATE pin. However, if a very small FET is used,
a resistor may be required between PGATE pin and the gate of the PFET to reduce high-frequency ringing.
Because this resistor will slow down the PFET’s rise time, the current limit blanking time must be taken into
consideration (see Current Limit Operation). The feedback voltage signal line can be sensitive to noise. Avoid
inductive coupling with the inductor or the switching node. The FB trace must be kept away from those areas.
Also, the orientation of the inductor can contribute un-wanted noise coupling to the FB path. If noise problems
are observed it may be worth trying a different orientation of the inductor and select the best for final component
placement.
10.2 Layout Examples
SPACE
Figure 30. LM3489 EVM PCB Top Layer Layout
Figure 31. LM3489 EVM PCB Bottom Layer Layout
Copyright © 2006–2016, Texas Instruments Incorporated
Product Folder Links: LM3489 LM3489-Q1
Submit Documentation Feedback
19
LM3489, LM3489-Q1
SNVS443C – MAY 2006 – REVISED DECEMBER 2016
www.ti.com
11 Device and Documentation Support
11.1 Related Links
The table below lists quick access links. Categories include technical documents, support and community
resources, tools and software, and quick access to sample or buy.
Table 1. Related Links
PARTS
PRODUCT FOLDER
SAMPLE & BUY
TECHNICAL
DOCUMENTS
TOOLS &
SOFTWARE
SUPPORT &
COMMUNITY
LM3489
Click here
Click here
Click here
Click here
Click here
LM3489-Q1
Click here
Click here
Click here
Click here
Click here
11.2 Receiving Notification of Documentation Updates
To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper
right corner, click on Alert me to register and receive a weekly digest of any product information that has
changed. For change details, review the revision history included in any revised document.
11.3 Community Resources
The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective
contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of
Use.
TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration
among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help
solve problems with fellow engineers.
Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and
contact information for technical support.
11.4 Trademarks
E2E is a trademark of Texas Instruments.
Simple Switchers is a registered trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
11.5 Electrostatic Discharge Caution
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
11.6 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
12 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
20
Submit Documentation Feedback
Copyright © 2006–2016, Texas Instruments Incorporated
Product Folder Links: LM3489 LM3489-Q1
PACKAGE OPTION ADDENDUM
www.ti.com
30-Sep-2021
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
(4/5)
(6)
LM3489MM
NRND
VSSOP
DGK
8
1000
Non-RoHS
& Green
Call TI
Level-1-260C-UNLIM
-40 to 125
SKSB
LM3489MM/NOPB
ACTIVE
VSSOP
DGK
8
1000
RoHS & Green
NIPDAUAG | SN
Level-1-260C-UNLIM
-40 to 125
SKSB
LM3489MMX/NOPB
ACTIVE
VSSOP
DGK
8
3500
RoHS & Green
NIPDAUAG | SN
Level-1-260C-UNLIM
-40 to 125
SKSB
LM3489QMM/NOPB
ACTIVE
VSSOP
DGK
8
1000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 125
STEB
LM3489QMMX/NOPB
ACTIVE
VSSOP
DGK
8
3500
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 125
STEB
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of