LM68440-Q1 TI | Alldatasheet
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Technical content
LM684x0-Q1 High Performance Stackable Power Converter, 3V to 36V, Pin-Compatible 4A, 6A, 8A, Automotive, Low EMI Synchronous Buck Converter for Functional Safety Applications
1 Features
- AEC-Q100 qualified for automotive applications: – Temperature grade 1: –40°C to +125°C, TA
- Functional Safety-Compliant – Developed for functional safety applications – Documentation available to aid ISO 26262 system design planned – Systematic capability up to ASIL D – Hardware capability up to ASIL C – Analog built-in-self-test at start-up – Redundant and fast (0.35μs) VOUT monitor – Feedback path failure detection – Redundant temperature sensor – Excellent pin FMEA and pin spacing
- Wide input voltage range: 3V to 36V
- Designed for low EMI requirements – Facilitates CISPR 25 class 5 compliance – Mode pin configurable ±5% or ±10% dual- random spread spectrum reducing peak emissions – Enhanced HotRod™ QFN package with symmetrical pinout – Switching frequency from 300kHz to 2.2MHz – Pin-configurable 400kHz and 2.1MHz – Pin-configurable AUTO or FPWM operation – Dual phase capable up to 16A for high current designs – Pin-pin with 65V LM686x5-Q1 family of devices
- Low minimum on time: 40ns (maximum)
- High-efficiency power conversion at all loads – > 94.65% peak efficiency at 12VIN, 5VOUT, 400kHz – 3.0µA PFM no-load input current
- High power density – Internal compensation, current limit, and TSD – 3.6mm × 2.6mm, wettable flank, 20-pin package – ϴJA = 24.0°C/W (LM654x0-Q1EVM)
- Create a custom design using the LM684x0-Q1 with the WEBENCH® Power Designer
2 Applications
- Advanced driver assistance systems (ADAS)
- Automotive infotainment and cluster
- Hybrid, electric, and powertrain systems
3 Description
The LM684x0-Q1 are a family of automotive buck converters designed for high efficiency, high power density, and ultra-low electromagnetic interference (EMI). The converters operate over a wide input voltage range of 3V to 36V (42V tolerant) The LM684x0-Q1 is dual phase capable by simply connecting the compensated error signal between the primary and secondary device. The LM684x0- Q1 comes with pin selectable fixed output voltages of 3.3V and 5V or in adjustable configuration. The low EMI operation is enabled with minimized loop inductance and optimized switch node slew rate. A pin-selectable ±5% or ±10% dual-random spread spectrum (DRSS) significantly reduces peak emissions through a combination of triangular and pseudo-random modulation while keeping output voltage ripple very low. The current-mode control architecture with a 30ns typical minimum on-time allows high conversion ratios at high frequencies coupled with a fast transient response and excellent load and line regulation. The LM684x0-Q1 buck converters are specifically intended for functional safety relevant applications. An array of safety features including ABIST at start- up, redundant and fast V OUT monitoring, feedback path failure detection, redundant temperature sensor, thermal shutdown, and current limiting significantly reduce the residual failure-in-time (FIT). Device Information PART NUMBER(3) PACKAGE(1) PACKAGE SIZE(2) LM68440-Q1 RZT (WQFN-FCRLF, 20) 3.6mm × 2.6mmLM68460-Q1 LM68480-Q1(4) (1) For more information, see Section 7. (2) The package size (length × width) is a nominal value and includes pins, where applicable. (3) See the Device Comparison Table. (4) Preview information (not Advance Information). ADVANCE INFORMATION LM68440-Q1, LM68460-Q1 SLVSJW0 – SEPTEMBER 2025 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. ADVANCE INFORMATION for preproduction products; subject to change without notice.
FSW = 2.2MHz VCC Simplified Schematic LM68440-Q1, LM68460-Q1 SLVSJW0 – SEPTEMBER 2025 www.ti.com
2 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated
Product Folder Links: LM68440-Q1 LM68460-Q1 ADVANCE INFORMATION
7 Mechanical, Packaging, and Orderable Information....7 www.ti.com LM68440-Q1, LM68460-Q1 SLVSJW0 – SEPTEMBER 2025 Copyright © 2025 Texas Instruments Incorporated Submit Document Feedback 3 Product Folder Links: LM68440-Q1 LM68460-Q1 ADVANCE INFORMATION
4 Device Comparison Table
ORDERABLE PART NUMBER CURRENT SAMPLING LM68440SRZTR(2) 4A No LM68460SRZTR 6A Yes LM68480SRZTR(1) (2) 8A No (1) For more information about sampling requests, please contact Texas Instruments. (2) Preview information (not Advance Information). LM68440-Q1, LM68460-Q1 SLVSJW0 – SEPTEMBER 2025 www.ti.com
4 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated
Product Folder Links: LM68440-Q1 LM68460-Q1 ADVANCE INFORMATION
5 Device and Documentation Support
5.1 Device Support
5.1.1 Third-Party Products Disclaimer
TI'S PUBLICATION OF INFORMATION REGARDING THIRD-PARTY PRODUCTS OR SERVICES DOES NOT CONSTITUTE AN ENDORSEMENT REGARDING THE SUITABILITY OF SUCH PRODUCTS OR SERVICES OR A WARRANTY, REPRESENTATION OR ENDORSEMENT OF SUCH PRODUCTS OR SERVICES, EITHER ALONE OR IN COMBINATION WITH ANY TI PRODUCT OR SERVICE.
5.1.2 Development Support
5.1.2.1 Custom Design With WEBENCH® Tools
Click here to create a custom design using the LM684x0-Q1 device with the WEBENCH® Power Designer. 1. Start by entering the input voltage (VIN), output voltage (VOUT), and output current (IOUT) requirements. 2. Optimize the design for key parameters such as efficiency, footprint, and cost using the optimizer dial. 3. Compare the generated design with other possible solutions from Texas Instruments. The WEBENCH Power Designer provides a customized schematic along with a list of materials with real-time pricing and component availability. In most cases, these actions are available:
- Run electrical simulations to see important waveforms and circuit performance
- Run thermal simulations to understand board thermal performance
- Export customized schematic and layout into popular CAD formats
- Print PDF reports for the design, and share the design with colleagues Get more information about WEBENCH tools at www.ti.com/WEBENCH.
5.2 Documentation Support
5.2.1 Related Documentation
For related documentation, see the following:
- Texas Instruments, Thermal Design by Insight not Hindsight application note
- Texas Instruments, A Guide to Board Layout for Best Thermal Resistance for Exposed Pad Packages application note
- Texas Instruments, How to Properly Evaluate Junction Temperature with Thermal Metrics application note
- Texas Instruments, Layout Guidelines for Switching Power Supplies application note
- Texas Instruments, AN-1229 SIMPLE SWITCHER® PCB Layout Guidelines application note
- Texas Instruments, Constructing Your Power Supply- Layout Considerations seminar
- Texas Instruments, Low Radiated EMI Layout Made Simple with LM4360x and LM4600x application note
- Texas Instruments, Semiconductor and IC Package Thermal Metrics application note
5.3 Receiving Notification of Documentation Updates
To receive notification of documentation updates, navigate to the device product folder on ti.com. Click on Notifications 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.
5.4 Support Resources
TI E2E™ support forums are an engineer's go-to source for fast, verified answers and design help — straight from the experts. Search existing answers or ask your own question to get the quick design help you need. Linked content is 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. www.ti.com LM68440-Q1, LM68460-Q1 SLVSJW0 – SEPTEMBER 2025 Copyright © 2025 Texas Instruments Incorporated Submit Document Feedback 5 Product Folder Links: LM68440-Q1 LM68460-Q1 ADVANCE INFORMATION
5.5 Trademarks
HotRod™ and TI E2E™ are trademarks of Texas Instruments. WEBENCH® is a registered trademark of Texas Instruments. All trademarks are the property of their respective owners.
5.6 Electrostatic Discharge Caution
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.
5.7 Glossary
TI Glossary This glossary lists and explains terms, acronyms, and definitions.
6 Revision History
September 2025 * Initial Release LM68440-Q1, LM68460-Q1 SLVSJW0 – SEPTEMBER 2025 www.ti.com
6 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated
Product Folder Links: LM68440-Q1 LM68460-Q1 ADVANCE INFORMATION
7 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.
7.1 Tape and Reel Information
Reel Width (W1) REEL DIMENSIONS W Dimension designed to accommodate the component length Dimension designed to accommodate the component thickness Overall width of the carrier tape Pitch between successive cavity centers Dimension designed to accommodate the component width TAPE DIMENSIONS B0 W A0Cavity QUADRANT ASSIGNMENTS FOR PIN 1 ORIENTATION IN TAPE Pocket Quadrants Sprocket Holes Q1 Q1Q2 Q2 Q3 Q3Q4 Q4 Reel Diameter User Direction of Feed Device Package Type Package Drawing Pins SPQ Reel Diameter (mm) Reel Width W1 (mm) (mm) (mm) (mm) (mm) W (mm) Pin1 Quadrant LM68440SRZTRQ1 WQFN- LM68460SRZTRQ1 WQFN- LM68480SRZTRQ1 WQFN- www.ti.com LM68440-Q1, LM68460-Q1 SLVSJW0 – SEPTEMBER 2025 Copyright © 2025 Texas Instruments Incorporated Submit Document Feedback 7 Product Folder Links: LM68440-Q1 LM68460-Q1 ADVANCE INFORMATION
TAPE AND REEL BOX DIMENSIONS Width (mm) W L H Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM68440SRZTRQ1 WQFN-FCRLF RZT 20 2500 346.0 346.0 33.0 LM68460SRZTRQ1 WQFN-FCRLF RZT 20 2500 346.0 346.0 33.0 LM68480SRZTRQ1 WQFN-FCRLF RZT 20 2500 346.0 346.0 33.0 LM68440-Q1, LM68460-Q1 SLVSJW0 – SEPTEMBER 2025 www.ti.com
8 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated
Product Folder Links: LM68440-Q1 LM68460-Q1 ADVANCE INFORMATION
www.ti.com PACKAGE OUTLINE 2.72.5 3.73.5 0.70.6 2.10.1 (0.85)
0.010.000.1 MIN
(0.075) DAP (0.18) TYP(0.21) TYP (0.1) WQFN-FCRLF - 0.7 mm max heightRZT0020APLASTIC QUAD FLATPACK - NO LEAD 4228518/C 06/2022 0.08C SCALE 4.500 PIN1 INDEX AREA SEATING PLANE PIN 1 ID 45X 0.2822X 45X 0.294 0.1CAB0.05C AA 7 11 1720 TYPICAL A-A40.000 SECTION A-A AB C www.ti.com LM68440-Q1, LM68460-Q1 SLVSJW0 – SEPTEMBER 2025 Copyright © 2025 Texas Instruments Incorporated Submit Document Feedback 9 Product Folder Links: LM68440-Q1 LM68460-Q1 ADVANCE INFORMATION
www.ti.com EXAMPLE BOARD LAYOUT .000 PKG 0 .000 PKG 0 4X 0.6254X 0.575 0.07 MAXALL AROUND0.07 MINALL AROUND (2.1) (0.95) (R0.05) TYP (0.2) TYPVIA 2X (1.007) 2X (0.372) 3X (R0.223) ()0.515()0.035 3X ()0.153X ()0.3 WQFN-FCRLF - 0.7 mm max heightRZT0020APLASTIC QUAD FLATPACK - NO LEAD SOLDER MASK DETAILS LAND PATTERN EXAMPLEEXPOSED METAL SHOWNSCALE: 20X SEE SOLDER MASKDETAILS1 7 11 1720 METAL EDGESOLDER MASKOPENINGEXPOSEDMETALNON SOLDER MASKDEFINED(PREFERRED) METAL UNDERSOLDER MASKSOLDER MASKOPENINGEXPOSEDMETALSOLDER MASKDEFINED LM68440-Q1, LM68460-Q1 SLVSJW0 – SEPTEMBER 2025 www.ti.com
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www.ti.com EXAMPLE STENCIL DESIGN .000 PKG 0 .000 PKG 0 2X 1.007 3X R0.2430.975 2X ()0.075 5X ()1.2 (0.905) 2X (0.9)2X (0.372) WQFN-FCRLF - 0.7 mm max heightRZT0020APLASTIC QUAD FLATPACK - NO LEAD 4228518/C 06/2022NOTES: (continued) 6. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate design recommendations. SOLDER PASTE EXAMPLEBASED ON 0.125 mm THICK STENCILSCALE: 20X EXPOSED PAD 21:85% PRINTED SOLDER COVERAGE BY AREA UNDER PACKAGE 7 11 1720 www.ti.com LM68440-Q1, LM68460-Q1 SLVSJW0 – SEPTEMBER 2025 Copyright © 2025 Texas Instruments Incorporated Submit Document Feedback 11 Product Folder Links: LM68440-Q1 LM68460-Q1 ADVANCE INFORMATION
www.ti.com 16-Oct-2025 PACKAGING INFORMATION Orderable part number Status (1) Material type (2) Package | Pins Package qty | Carrier RoHS (3) Lead finish/ Ball material (4) MSL rating/ Peak reflow (5) Op temp (°C) Part marking (6) PLM68460SFRZTRQ1 Active Preproduction WQFN-FCRLF (RZT) | 20 3000 | LARGE T&R - Call TI Call TI -40 to 150 (1) Status: For more details on status, see our product life cycle. (2) Material type: When designated, preproduction parts are prototypes/experimental devices, and are not yet approved or released for full production. Testing and final process, including without limitation quality assurance, reliability performance testing, and/or process qualification, may not yet be complete, and this item is subject to further changes or possible discontinuation. If available for ordering, purchases will be subject to an additional waiver at checkout, and are intended for early internal evaluation purposes only. These items are sold without warranties of any kind. (3) RoHS values: Yes, No, RoHS Exempt. See the TI RoHS Statement for additional information and value definition. (4) Lead finish/Ball material: Parts may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two lines if the finish value exceeds the maximum column width. (5) MSL rating/Peak reflow: The moisture sensitivity level ratings and peak solder (reflow) temperatures. In the event that a part has multiple moisture sensitivity ratings, only the lowest level per JEDEC standards is shown. Refer to the shipping label for the actual reflow temperature that will be used to mount the part to the printed circuit board. (6) Part marking: There may be an additional marking, which relates to the logo, the lot trace code information, or the environmental category of the part. Multiple part markings will be inside parentheses. Only one part marking contained in parentheses and separated by a "~" will appear on a part. If a line is indented then it is a continuation of the previous line and the two combined represent the entire part marking for that device. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 1
www.ti.com PACKAGE OUTLINE 2.7 2.5 3.7 3.5 0.7 0.6 2X 1.5 .000 PKG 0 2X 1 2X 0.5 2X 0.5 2X 1 2X 1.5 2X 1.05 .000 PKG 0 2X 0.55 2X 0.05 2X 0.5 2X 1.05 2.1 0.1 0.95 0.1 24X 0.3 0.2 16X 0.5 0.3 4X 0.475 0.275 4X 0.525 0.325 (0.85) (0.85) 0.01 0.00
0.1 MIN
(0.075) DAP (0.18) TYP (0.21) TYP (0.1) WQFN-FCRLF - 0.7 mm max heightRZT0020A PLASTIC QUAD FLATPACK - NO LEAD 4228518/C 06/2022 0.08 C NOTES: 1. All linear dimensions are in millimeters. Any dimensions in parenthesis are for reference only. Dimensioning and tolerancing per ASME Y14.5M. 2. This drawing is subject to change without notice. 3. The package thermal pad must be soldered to the printed circuit board for thermal and mechanical performance. SCALE 4.500 PIN1 INDEX AREA SEATING PLANE PIN 1 ID 45 X 0.282 2X 45 X 0.294
0.1 C A B
0.05 C A A 7 11 A-A40.000 SECTION A-A TYPICAL AB C
www.ti.com EXAMPLE BOARD LAYOUT .000 PKG 0 .000 PKG 0 4X 0.625 4X 0.575
0.07 MAX
0.07 MIN
( ) 1.7 2X ( ) 1.5 2X ( ) 1 2X ( ) 0.5 2X ( ) 0.5 2X ( ) 1 2X ( ) 1.5 ( ) 1.7 ( ) 1.2 2X ( ) 1.05 2X ( ) 0.55 2X ( ) 0.05 2X ( ) 0.5 2X ( ) 1.05 ( ) 1.2 (2.1) (0.95) 16X (0.6) 24X (0.25) (R0.05) TYP ( 0.2) TYP VIA 2X (1.007) 2X (0.372) 3X (R0.223) ( ) 0.515 ( ) 0.035 3X ( ) 0.15 3X ( ) 0.3 ( ) 0.79 ( ) 0.24 ( ) 0.31 ( ) 0.585 WQFN-FCRLF - 0.7 mm max heightRZT0020A PLASTIC QUAD FLATPACK - NO LEAD 4228518/C 06/2022 NOTES: (continued) 4. This package is designed to be soldered to a thermal pad on the board. For more information, see Texas Instruments literature number SLUA271 (www.ti.com/lit/slua271). 5. Vias are optional depending on application, refer to device data sheet. If any vias are implemented, refer to their locations shown on this view. It is recommended that vias under paste be filled, plugged or tented. SOLDER MASK DETAILS LAND PATTERN EXAMPLE EXPOSED METAL SHOWN SCALE: 20X SEE SOLDER MASK DETAILS METAL EDGE SOLDER MASK OPENING EXPOSED METAL NON SOLDER MASK DEFINED (PREFERRED) METAL UNDER SOLDER MASK SOLDER MASK OPENING EXPOSED METAL SOLDER MASK DEFINED
www.ti.com EXAMPLE STENCIL DESIGN .000 PKG 0 .000 PKG 0 2X 1.007 3X R0.243 0.975 3X ( ) 1.7 2X ( ) 1.5 2X ( ) 1 2X ( ) 0.5 ( ) 0.588 2X ( ) 0.5 ( ) 0.553 2X ( ) 1 2X ( ) 1.5 3X ( ) 1.7 5X ( ) 1.2 2X ( ) 1.05 2X ( ) 0.55 2X ( ) 0.05 2X ( ) 0.5 2X ( ) 1.05 2X ( ) 0.075 5X ( ) 1.2 (R0.05) TYP 4X (0.625) 4X (0.575) 16X (0.6) 24X (0.25) (0.905) 2X (0.9) 2X (0.372) WQFN-FCRLF - 0.7 mm max heightRZT0020A PLASTIC QUAD FLATPACK - NO LEAD 4228518/C 06/2022 NOTES: (continued) 6. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate design recommendations. SOLDER PASTE EXAMPLE BASED ON 0.125 mm THICK STENCIL SCALE: 20X EXPOSED PAD 21: 85% PRINTED SOLDER COVERAGE BY AREA UNDER PACKAGE
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