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Texas Instruments LMS3655LQRNLRQ1
- Part No.:
- LMS3655LQRNLRQ1
- Manufacturer:
- Texas Instruments
- Package:
- 22-PowerVFQFN
- Datasheet:
-
LMS3655LQRNLRQ1.pdf
- Description:
- IC REG BUCK 5V 5.5A 22VQFN
- Quantity:
- Payment:
- Shipping:
Inventory:3,490
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Product details
Overview
LMS3655LQRNLRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive synchronous buck converter delivering 5.5-A continuous output at 5 V with 400-kHz fixed switching frequency, 96% peak efficiency (12 V → 5 V), and 36-V max input voltage (42-V transient tolerant). It integrates high-side/low-side MOSFETs, internal compensation, soft-start, thermal shutdown, and a filtered open-drain RESET output - deployed in vehicle USB charging and surround-view ECU power rails.
For engineers reviewing the LMS3655LQRNLRQ1 datasheet, LMS3655LQRNLRQ1 pinout, LMS3655LQRNLRQ1 application, or LMS3655LQRNLRQ1 equivalent, key selection criteria include its 5.5-A rated current, spread-spectrum EMI reduction, –40°C to +125°C ambient operation, 18-µA quiescent current at 3.3 VOUT, and 5-V fixed output with ±1.5% reference tolerance - all validated for automotive safety-critical subsystems.
Technical Context
The LMS3655LQRNLRQ1 employs peak current mode control with integrated gate drivers and flip-chip HotRod™ packaging to minimize switch-node ringing and radiated EMI. Its frequency foldback architecture enables regulation from as low as 3.5 V input while maintaining 5-V output, and external SYNC input allows synchronization to system clocks between 250 kHz and 500 kHz.
It features automatic light-load PFM/PWM transition, pin-selectable forced PWM mode via FPWM input, and a built-in 3-ms RESET release timer with glitch filtering. The device uses a single 1-V internal reference (±1.5% tolerance) and supports output adjustment from 1 V to 20 V in adjustable variants - though LMS3655LQRNLRQ1 is factory-configured for fixed 5-V output with spread-spectrum enabled.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 5.5 A continuous - supports high-power automotive ECUs without external current boosting |
| Input Voltage Range | 3.5 V to 36 V - enables cold-crank operation down to 3.5 V and surge resilience up to 42 V (≤500 ms) |
| Switching Frequency | 400 kHz ±10% - balances efficiency, size, and EMI; synchronizable to 250–500 kHz external clock |
| Quiescent Current | 18 µA at 3.3 VOUT, no load - extends battery life in always-on automotive modules |
| Output Voltage Accuracy | ±1.5% reference tolerance - ensures stable 5.0 V output across temperature and line/load variations |
| Efficiency (12 V → 5 V) | 96% peak - reduces thermal stress and enables compact heatsink-free PCB layout |
| RESET Output | Open-drain with 3-ms release timer and 24-µs glitch filter - replaces discrete supervisor ICs |
Pinout & Package
Package: 22-pin VQFN (RNL), 4.0 mm × 5.0 mm body size, wettable flanks for automated optical solder inspection.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 VCC | Internal 3.1-V LDO output | Power supply for internal control circuitry; requires 4.7-µF capacitor to AGND |
| 2 CBOOT | Bootstrap capacitor node | Drives high-side MOSFET gate; connects to SW via 470-nF capacitor |
| 3 SYNC | Frequency synchronization input | Rising-edge triggered; accepts 250–500 kHz external clock for EMI reduction |
| 4,14 PVIN1/PVIN2 | Main power inputs | Parallel-connected VIN pins; require local ceramic bypass capacitors to PGND |
| 5,10 PGND1/PGND2 | Power ground return | Low-impedance path for high-side/low-side MOSFET currents; must be tied together on PCB |
| 9 SW | Switch node | Connects to power inductor; high dv/dt node requiring minimized trace area |
| 15 AVIN | Analog input supply | Bias source for analog circuits; connect directly to PVIN1/PVIN2 on PCB |
| 16 FPWM | Forced PWM mode control | High = fixed-frequency PWM; low = automatic light-load PFM/PWM transition |
| 18 EN | Enable input | Active-high logic; 1.7–2.0 V threshold with 0.45–0.55 V hysteresis; do not float |
| 19 RESET | Open-drain reset flag | Asserts low during fault or EN=low; requires external pullup; includes 3-ms release delay |
| 20 AGND | Analog ground reference | Reference for FB, VREF, and internal analog blocks; tie to PGND at single point |
| 21 FB | Feedback input | Monitors regulated 5-V output; internally connected to fixed 5-V divider (no external resistors) |
| 22 BIAS | Auxiliary bias regulator input | Connected to output node to improve light-load efficiency and enable low-input operation |
Key Features
| Feature | Design Value |
|---|---|
| Spread-spectrum modulation | Reduces peak conducted EMI by ±3% frequency dithering - eliminates need for external EMI filters |
| Integrated high-side/low-side MOSFETs | RDSON of 60–130 mΩ (HS) and 40–80 mΩ (LS) - enables 5.5-A output without external switches |
| Automatic light-load mode | Transitions to diode-emulation PFM below ~100 mA - maintains >85% efficiency at microamp loads |
| Thermal shutdown protection | 160–185°C trip threshold with 15°C hysteresis - prevents damage during sustained overload or poor airflow |
| Wettable flank package | VQFN-22 with solderable side walls - enables AOI-based solder joint verification without X-ray |
Applications
| Automotive USB Charging | Surround-View System ECU |
|---|---|
|
Use Scenario: Powering dual-port 5-V/3-A USB Type-C PD modules in center console or rear-seat infotainment. IC Role / Device Role / Timing Role: Primary 5-V buck regulator supplying USB controller, PHY, and port power switches. Use Value: 96% efficiency minimizes heat in confined console enclosures; 42-V transient tolerance withstands load-dump events. |
Use Scenario: Providing stable 5-V rail to image signal processors (ISP), SerDes transceivers, and camera interface logic. IC Role / Device Role / Timing Role: High-current, low-noise power stage for multi-camera video processing subsystems. Use Value: Spread-spectrum operation suppresses switching noise coupling into analog video paths; RESET output validates power integrity before ISP boot. |
| Driver Monitoring Systems | Mechanically Scanning LIDAR |
|
Use Scenario: Supplying 5-V power to infrared LED drivers, time-of-flight sensors, and eye-tracking SoCs in driver attention modules. IC Role / Device Role / Timing Role: Main DC-DC converter enabling always-on operation with ultra-low IQ (18 µA). Use Value: 18-µA quiescent current extends battery runtime during vehicle sleep mode; AEC-Q100 Grade 1 ensures reliability at +125°C ambient. |
Use Scenario: Delivering regulated 5-V power to laser diode drivers, MEMS mirror controllers, and ADC front-ends in long-range LIDAR units. IC Role / Device Role / Timing Role: High-efficiency, low-EMI power source synchronized to system timing to avoid interference with echo detection. Use Value: SYNC input allows alignment of switching edges with LIDAR pulse timing; frequency foldback enables operation from 3.5-V backup battery during main rail dropout. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM61480QRNLRQ1 | 8-A output, 2.5-V to 36-V input, 2.1-MHz switching, no spread spectrum | Better suited for space-constrained designs needing higher current and faster transient response | Select when board area is limited and >5.5-A peak load is required; verify EMI compliance without spread spectrum |
| TPS54560QDGQRQ1 | 5.5-A output, 3.5-V to 60-V input, 100–2500-kHz adjustable frequency, no integrated high-side FET | Requires external high-side MOSFET; supports wider input range but adds BOM and layout complexity | Choose when input may exceed 36 V (e.g., commercial truck 24-V systems); accept added design effort for extended VIN |
Compared with LM61480QRNLRQ1 and TPS54560QDGQRQ1, the LMS3655LQRNLRQ1 offers superior EMI performance via integrated spread spectrum and lower quiescent current (18 µA vs. 40 µA+), making it optimal for always-on automotive modules where thermal and noise constraints dominate.
Availability
LMS3655LQRNLRQ1 is available at Aetrix Electronics and suitable for automotive USB charging, surround-view ECU, and driver monitoring systems requiring stable component supply, AEC-Q100 qualification, and long-term production continuity.
Supply support for LMS3655LQRNLRQ1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and automotive-grade power management ICs, with over 50 years of innovation in high-reliability electronics.
The LMS3655-Q1 product line delivers high-current, low-EMI synchronous buck regulators optimized for automotive ADAS, infotainment, and body electronics - designed to replace discrete power stages while meeting stringent AEC-Q100 and functional safety requirements.
FAQ
What is the maximum continuous output current of the LMS3655LQRNLRQ1?
The LMS3655LQRNLRQ1 delivers 5.5 A continuous output current at 5 V under recommended operating conditions (–40°C to +125°C ambient, proper PCB thermal design). This rating is validated with internal MOSFETs and accounts for thermal derating above 85°C ambient. Peak current capability reaches 9.5 A before cycle-by-cycle current limit triggers, as specified in the datasheet's IL-HS parameter.
Does the LMS3655LQRNLRQ1 support adjustable output voltage?
No, the LMS3655LQRNLRQ1 is factory-configured for fixed 5-V output with spread-spectrum modulation enabled. It does not support external resistor feedback adjustment. For adjustable output, select LMS3655AQRNLRQ1 (adjustable, no spread spectrum) or LMS3655MQRNLRQ1 (adjustable, with spread spectrum). The FB pin on LMS3655LQRNLRQ1 is internally connected to the 5-V divider network.
What is the purpose of the BIAS pin on the LMS3655LQRNLRQ1?
The BIAS pin on the LMS3655LQRNLRQ1 supplies the auxiliary bias regulator that powers internal analog circuitry during light-load operation. It must be connected to the 5-V output node to enable low-IQ PFM mode and extend minimum input voltage capability down to 3.5 V. Leaving BIAS unconnected degrades light-load efficiency and disables frequency foldback functionality.
How does the RESET output function on the LMS3655LQRNLRQ1?
The RESET output on the LMS3655LQRNLRQ1 is an open-drain flag that asserts low when output voltage falls below 94% of nominal (4.7 V for 5-V output), during thermal shutdown, or when EN is low. It features a built-in 24-µs glitch filter and a 3-ms release timer after fault clearance. An external pullup resistor (typically 10 kΩ to 3.3 V or 5 V) is required to generate a valid logic-high signal.
Is the LMS3655LQRNLRQ1 pin-compatible with other LMS36x5-Q1 variants?
Yes, all LMS36x5-Q1 devices, including LMS3655LQRNLRQ1, share identical 22-pin VQFN (RNL) packaging, pinout, and footprint. This allows direct substitution between fixed-output (3.3 V, 5 V) and adjustable versions, as well as spread-spectrum and non-spread-spectrum variants - provided external components (e.g., feedback resistors, spread-spectrum enable) match the selected variant's configuration.
LMS3655LQRNLRQ1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 22-PowerVFQFN
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3.9V
- Voltage - Input (Max):
- 36V
- Voltage - Output (Min/Fixed):
- 5V
- Voltage - Output (Max):
- -
- Current - Output:
- 5.5A
- Frequency - Switching:
- 250kHz ~ 500kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount, Wettable Flank
- Supplier Device Package:
- 22-VQFN-HR (5x4)
LMS3655LQRNLRQ1 FAQ
1.How can I place an order for LMS3655LQRNLRQ1 through Aetrix?
Please submit a Request for Quotation (RFQ) for LMS3655LQRNLRQ1 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LMS3655LQRNLRQ1 reliable?
The price and inventory of LMS3655LQRNLRQ1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LMS3655LQRNLRQ1 is usually 5 days.
3.What payment methods are accepted for LMS3655LQRNLRQ1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LMS3655LQRNLRQ1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LMS3655LQRNLRQ1?
LMS3655LQRNLRQ1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LMS3655LQRNLRQ1 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LMS3655LQRNLRQ1?
For technical support, including LMS3655LQRNLRQ1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LMS3655LQRNLRQ1 requirements.
6.How does Aetrix verify that LMS3655LQRNLRQ1 is sourced from the original manufacturer or authorized distributors?
All LMS3655LQRNLRQ1 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LMS3655LQRNLRQ1 meets industry standards.
7.What is the process for return or replacement of LMS3655LQRNLRQ1?
All LMS3655LQRNLRQ1 units undergo pre-shipment inspection (PSI). If there is an issue with LMS3655LQRNLRQ1, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LMS3655LQRNLRQ1 part is unused and in its original packaging.
Return procedure for LMS3655LQRNLRQ1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LMS3655LQRNLRQ1 Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
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