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Texas Instruments LMR36503RS5QRPERQ1
- Part No.:
- LMR36503RS5QRPERQ1
- Manufacturer:
- Texas Instruments
- Package:
- 9-PowerVFQFN
- Datasheet:
-
LMR36503RS5QRPERQ1.pdf
- Description:
- IC REG BUCK 5V 300MA 9VQFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,399
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Product details
Overview
LMR36503RS5QRPERQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive-grade synchronous buck converter delivering 5 V fixed output at up to 0.3 A, operating from 3 V to 65 V input, featuring 4 µA switching quiescent current, 2.2 MHz nominal switching frequency (adjustable via RT pin), and integrated PGOOD flag - deployed in ADAS power rails and infotainment domain controllers.
For engineers reviewing the LMR36503RS5QRPERQ1 datasheet, LMR36503RS5QRPERQ1 pinout, LMR36503RS5QRPERQ1 application, or LMR36503RS5QRPERQ1 equivalent, key selection criteria include cold-crank robustness (3.0 V falling threshold), spread-spectrum EMI compliance per CISPR 25, internal compensation for minimal external components, and 2-mm × 2-mm HotRod™ VQFN-HR package with wettable flanks for automated optical inspection.
Technical Context
The LMR36503RS5QRPERQ1 implements peak current mode control with internal compensation and seamless FPWM-to-PFM transition, enabling stable regulation down to zero load while maintaining >70% efficiency at 5 mA. Its RT pin variant supports externally adjustable switching frequency from 200 kHz to 2.2 MHz using a single resistor, and its fixed 5-V output eliminates external feedback resistors.
Designed for automotive environments, it features –40°C to +150°C junction temperature operation, pseudo-random spread spectrum dithering, and built-in thermal shutdown (158°C rising, 150°C falling) with 10°C hysteresis - all within a leadless VQFN-HR (9-pin, RPE) package optimized for board-level reliability and EMI performance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.0 V (falling) to 65 V - sustains regulation during severe cold-crank transients (e.g., 4.5 V @ –40°C engine start) |
| Output Voltage | Fixed 5.0 V ±1.5% (FPWM mode) - eliminates need for external feedback divider and reduces BOM count |
| Max Output Current | 0.3 A continuous - sufficient for powering microcontrollers, sensors, and CAN transceivers in body electronics |
| Quiescent Current | 4 µA (switching, VIN=24 V → VOUT=3.3 V) - enables always-on systems with multi-year battery life in parked state |
| Switching Frequency | Adjustable 200 kHz–2.2 MHz via RT pin - allows EMI optimization and inductor size trade-off without changing IC |
| Package | VQFN-HR (RPE), 2 mm × 2 mm, 9-pin - wettable flanks enable AOI; corner anchor pins improve solder joint reliability |
| PGOOD Accuracy | ±1.5% window (94–107% of VOUT/BIAS) with 25 µs glitch filter - replaces external supervisor IC in most applications |
Pinout & Package
VQFN-HR (RPE) package: 2.00 mm × 2.00 mm body, 9-pin, wettable flanks, exposed thermal pad (GND-connected), RoHS-compliant, JEDEC-standard footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - RT | Frequency programming input | Connect to GND for 2.2 MHz, to VCC for 1 MHz, or to resistor-to-GND for 200 kHz–2.2 MHz - no external clock required |
| 2 - PGOOD | Open-drain power-good flag | Signals valid output (106–110% / 93–96.5% thresholds); 20–70 Ω RDS(on); requires pull-up but no external supervisor |
| 3 - EN/UVLO | Enable & input undervoltage lockout | Active-high enable with 1.263 V threshold and 0.35 V hysteresis - direct connection to VIN allowed; prevents false turn-on during brownout |
| 4 - VIN | Main input power supply | Accepts 3–65 V; requires local high-quality bypass capacitor; withstands 70 V transients |
| 5 - SW | Power switch node | Connects to external inductor; carries high di/dt; must be routed with short, low-inductance path |
| 6 - BOOT | High-side gate driver supply | Requires 100 nF ceramic capacitor to SW; UVLO threshold 2.3 V - ensures reliable HS FET drive under light load |
| 7 - VCC | Internal LDO output | 3.15 V ±25 mV regulated supply for control circuitry; 240 mA current limit; decouple with 1 µF to GND |
| 8 - VOUT/BIAS | Fixed 5-V output sense & bias | Internally connected to output; provides accurate reference for PGOOD and internal regulation - no FB divider needed |
| 9 - GND | Power ground | Thermal pad and pin both connect to system GND; requires low-impedance plane tie to CIN and COUT |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 Grade 1 qualification | Validated for –40°C to +125°C ambient (–40°C to +150°C junction), meeting automotive reliability and stress-test requirements |
| Pseudo-random spread spectrum | ±2% frequency dithering at ~1.2 Hz - reduces peak EMI by >10 dB, enabling CISPR 25 Class 5 compliance without shielding |
| Ultra-low IQ in PFM mode | 4 µA at 24 VIN → 3.3 VOUT - extends battery runtime in always-on vehicle modules (e.g., telematics wake-up circuits) |
| Integrated PGOOD with delay | 2.16 ms assertion delay and 25 µs glitch filter - eliminates need for external reset supervisor IC and associated timing components |
| Internal compensation | Single-stage Type II compensation embedded - removes need for external compensation network, reducing layout sensitivity and design cycle time |
Applications
| ADAS Camera Power Supply | Body Control Module Rail |
|---|---|
Use Scenario: Powers image sensor and ISP in forward-facing monocular camera during engine cranking and stop-start cycles. IC Role / Device Role / Timing Role: Primary 5-V buck regulator supplying critical vision subsystem; handles 4.5–65 V input sag and surge per ISO 7637-2 Pulse 4. Use Value: Maintains regulation at 3.0 V input (falling threshold), delivers 0.3 A with <1.5% output error, and suppresses EMI to avoid corrupting pixel data transmission. | Use Scenario: Supplies 5 V to door module MCU, LIN transceiver, and LED drivers in centralized body electronics architecture. IC Role / Device Role / Timing Role: Always-on auxiliary rail with ultra-low standby current; enables fast wake-from-sleep response (<2.7 ms soft-start) and precise power sequencing. Use Value: 4 µA quiescent current extends 12-V battery life beyond 10 years in parked state; PGOOD replaces discrete supervisor, saving 3 passives and 2 mm² PCB area. |
| Infotainment Head Unit Core Logic | Digital Cluster Display Bias |
Use Scenario: Generates clean 5 V for ARM Cortex-A53 SoC core logic and DDR memory interface in automotive head unit. IC Role / Device Role / Timing Role: High-efficiency intermediate rail; synchronizes switching to system clock via MODE/SYNC pin (in compatible variants) to minimize beat frequencies. Use Value: >70% efficiency at 5 mA idle current reduces thermal load on densely packed PCB; 2.2 MHz operation avoids AM band interference. | Use Scenario: Provides stable 5 V bias for TFT LCD backlight controller and touch controller in digital instrument cluster. IC Role / Device Role / Timing Role: Fixed-output point-of-load regulator; uses internal VOUT/BIAS sensing for tight regulation across temperature and line variation. Use Value: ±1.5% output accuracy ensures consistent display brightness and touch response; spread spectrum prevents visual flicker caused by EMI coupling into analog video paths. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LMR36503RS3QRPERQ1 | Identical package, pinout, and features - only differs in factory-trimmed fixed 3.3 V output | Suitable where 3.3 V logic rail is required instead of 5 V; shares same thermal and EMI behavior | Select when system requires 3.3 V for MCU I/O or peripheral interfaces; no layout change needed |
| LMR36506RS5QRPERQ1 | Pin-compatible 65 V, 0.6 A variant with identical RT pin functionality and spread spectrum; higher current capability | Used in higher-power domains (e.g., radar power supply, gateway MCU core); same footprint but higher thermal dissipation | Choose when load exceeds 0.3 A or future-proofing for higher-current derivatives is required; same PCB layout |
Compared with LMR36503RS3QRPERQ1, the LMR36503RS5QRPERQ1 offers matched performance at 5 V output, eliminating revalidation of feedback networks; versus LMR36506RS5QRPERQ1, it trades current headroom for lower cost and reduced thermal management complexity in sub-300-mA applications.
Availability
LMR36503RS5QRPERQ1 is available at Aetrix Electronics and suitable for advanced driver assistance systems (ADAS), body electronics and lighting, and infotainment and cluster applications requiring stable component supply, automotive-grade traceability, and long-term production continuity.
Supply support for LMR36503RS5QRPERQ1 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 company headquartered in Dallas, Texas, specializing in analog, embedded processing, and automotive ICs with over 50 years of automotive qualification experience.
The LMR36503-Q1 product line was developed specifically for space-constrained, EMI-sensitive automotive power rails - emphasizing ultra-small solution size, light-load efficiency, and robust transient handling in harsh vehicle electrical environments.
FAQ
What is the minimum input voltage at which LMR36503RS5QRPERQ1 maintains regulation?
The LMR36503RS5QRPERQ1 maintains regulation down to a falling input voltage threshold of 3.0 V, verified across temperature and load. This enables reliable operation during deep cold-crank events in 12-V automotive systems, where battery voltage can dip below 5 V for extended periods. The device remains functional until VIN falls below this threshold, after which it enters UVLO shutdown.
Does LMR36503RS5QRPERQ1 require external compensation components?
No, the LMR36503RS5QRPERQ1 features fully internal compensation optimized for stability with minimal output capacitance. This eliminates external Type II compensation networks (e.g., RCZ feedback), simplifying layout, reducing BOM count by up to 4 passive components, and improving design repeatability across varying output capacitor ESR values.
How does the PGOOD function work on LMR36503RS5QRPERQ1?
The LMR36503RS5QRPERQ1 PGOOD pin is an open-drain output asserting high when VOUT/BIAS reaches 106–110% of nominal 5 V and deasserting low when it falls below 93–96.5%. It includes a 25 µs internal glitch filter and 2.16 ms delay after soft-start completion - providing precise, noise-immune power-good signaling that replaces external supervisor ICs in most automotive designs.
Can LMR36503RS5QRPERQ1 be synchronized to an external clock?
No - the LMR36503RS5QRPERQ1 is the RT pin variant and does not include MODE/SYNC functionality. Synchronization capability is exclusive to the MODE/SYNC pin variants (e.g., LMR36503MSC5RPERQ1). The RT pin on LMR36503RS5QRPERQ1 is dedicated to resistor-based frequency programming only and cannot accept external clock signals.
What is the thermal shutdown behavior of LMR36503RS5QRPERQ1?
The LMR36503RS5QRPERQ1 triggers thermal shutdown at 158°C (rising threshold) and resumes operation once junction temperature falls to 150°C (falling threshold), yielding 8°C hysteresis. This protects against sustained overload or poor heatsinking. During shutdown, the device disables switching, pulls PGOOD low, and draws only ~1 µA quiescent current - ensuring safe recovery without system latch-up.
LMR36503RS5QRPERQ1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 9-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):
- 3V
- Voltage - Input (Max):
- 65V
- Voltage - Output (Min/Fixed):
- 5V
- Voltage - Output (Max):
- -
- Current - Output:
- 300mA
- Frequency - Switching:
- 200kHz ~ 2.2MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount, Wettable Flank
- Supplier Device Package:
- 9-VQFN-HR (2x2)
LMR36503RS5QRPERQ1 FAQ
1.How can I place an order for LMR36503RS5QRPERQ1 through Aetrix?
Please submit a Request for Quotation (RFQ) for LMR36503RS5QRPERQ1 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 LMR36503RS5QRPERQ1 reliable?
The price and inventory of LMR36503RS5QRPERQ1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LMR36503RS5QRPERQ1 is usually 5 days.
3.What payment methods are accepted for LMR36503RS5QRPERQ1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LMR36503RS5QRPERQ1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LMR36503RS5QRPERQ1?
LMR36503RS5QRPERQ1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LMR36503RS5QRPERQ1 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 LMR36503RS5QRPERQ1?
For technical support, including LMR36503RS5QRPERQ1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LMR36503RS5QRPERQ1 requirements.
6.How does Aetrix verify that LMR36503RS5QRPERQ1 is sourced from the original manufacturer or authorized distributors?
All LMR36503RS5QRPERQ1 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 LMR36503RS5QRPERQ1 meets industry standards.
7.What is the process for return or replacement of LMR36503RS5QRPERQ1?
All LMR36503RS5QRPERQ1 units undergo pre-shipment inspection (PSI). If there is an issue with LMR36503RS5QRPERQ1, 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 LMR36503RS5QRPERQ1 part is unused and in its original packaging.
Return procedure for LMR36503RS5QRPERQ1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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