Texas Instruments LMR36006FSC3RNXTQ1

Overview

LMR36006FSC3RNXTQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive-grade synchronous step-down DC/DC converter delivering 0.6 A at fixed 3.3 V output, operating from 4.2 V to 60 V input, with 2.1-MHz switching frequency, spread-spectrum modulation, and FPWM mode support. It integrates high-side and low-side MOSFETs in a 2-mm × 3-mm HotRod™ VQFN-HR package for ADAS camera modules and body control units.

For engineers reviewing the LMR36006FSC3RNXTQ1 datasheet, LMR36006FSC3RNXTQ1 pinout, LMR36006FSC3RNXTQ1 application, or LMR36006FSC3RNXTQ1 equivalent, key selection criteria include its fixed 3.3-V output, 2.1-MHz FPWM operation, AEC-Q100 qualification, thermal shutdown (170°C), and power-good flag with 80–200 µs deglitch delay - all critical for automotive power rail integrity and functional safety design.

Technical Context

The LMR36006FSC3RNXTQ1 uses peak-current-mode control with internal loop compensation, enabling stable regulation across 4.2–60 V input while maintaining ±1.5% reference voltage tolerance and 3.23–3.37 V output accuracy over temperature. Its FPWM mode ensures constant-frequency operation under all load conditions, eliminating audible noise and simplifying EMI filtering.

It implements dual current-limit protection: cycle-by-cycle high-side peak limit (0.8–1.2 A) and valley-based low-side limit (0.6–0.95 A), plus hiccup-mode short-circuit response triggered below 0.4 V on FB. The integrated 5-V VCC LDO (4.75–5.25 V) powers internal circuitry and supports logic-level PG pull-up, with EN thresholds of 1.157–1.3 V (rising) and 1.047–1.19 V (falling).

Key Specifications

Pinout & Package

LMR36006FSC3RNXTQ1 is housed in a 12-pin VQFN-HR (RNX) package measuring 2.00 mm × 3.00 mm with wettable flanks, optimized for automated optical inspection and thermal performance (R_θJA = 72.5°C/W, R_θJB = 23.3°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck converter applications.

Compared with LMR36006AQRNXTQ1, the LMR36006FSC3RNXTQ1 saves BOM cost and layout effort via fixed 3.3-V output and delivers superior EMI performance; versus LMR36006FSCQRNXTQ1, it adds ±4% spread spectrum to further suppress narrowband emissions without sacrificing efficiency or thermal performance.

Availability

LMR36006FSC3RNXTQ1 is available at Aetrix Electronics and suitable for ADAS camera modules, body control modules, and infotainment displays requiring stable component supply, automotive qualification, and long-term production continuity.

Supply support for LMR36006FSC3RNXTQ1 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 designing analog ICs, embedded processors, and connectivity solutions for automotive, industrial, and consumer markets.

The LMR36006-Q1 product line delivers ultra-small, high-voltage synchronous buck converters optimized for automotive power systems where AEC-Q100 compliance, functional safety readiness, and ultra-low EMI are mandatory.

FAQ

What is the output voltage configuration of the LMR36006FSC3RNXTQ1?

The LMR36006FSC3RNXTQ1 features a factory-trimmed fixed 3.3-V output, with guaranteed accuracy of 3.23 V to 3.37 V over temperature and load. Unlike adjustable variants, it requires no external feedback resistors - the FB pin connects directly to the output node. This configuration reduces component count, improves stability, and eliminates resistor tolerance errors that affect regulation precision in the LMR36006FSC3RNXTQ1.

Does the LMR36006FSC3RNXTQ1 support functional safety certification in automotive systems?

Yes, the LMR36006FSC3RNXTQ1 is Functional Safety-Capable, with TI providing a dedicated functional safety documentation package including FMEDA reports, FIT rate data (124.3 FIT), and safety manual to support ISO 26262 ASIL-B system development. While the LMR36006FSC3RNXTQ1 itself is not ASIL-certified, its documented failure modes and diagnostic coverage enable integration into ASIL-B compliant power architectures - a key differentiator versus non-automotive buck regulators.

How does the power-good (PG) flag of the LMR36006FSC3RNXTQ1 behave during startup and fault conditions?

The LMR36006FSC3RNXTQ1 PG pin is an open-drain output that goes high only after soft-start completes and V_OUT reaches ≥95% of nominal (3.135 V). It remains high during normal operation and pulls low during faults (thermal shutdown, current limit, or EN deassertion). With built-in 80–200 µs deglitching, brief transients do not trigger false resets. For reliable MCU reset sequencing, the LMR36006FSC3RNXTQ1 PG output must be pulled up to V_CC or V_OUT via a 10-kΩ resistor.

What thermal metrics define the LMR36006FSC3RNXTQ1's PCB-level cooling performance?

The LMR36006FSC3RNXTQ1 in its 2-mm × 3-mm VQFN-HR (RNX) package has R_θJA = 72.5°C/W (JEDEC standard), R_θJB = 23.3°C/W (board-conducted), and R_θJC(top) = 35.9°C/W. These values assume 2 oz copper, 4-layer PCB with thermal vias under the exposed pad. At 0.6-A load and 24-V input, junction temperature rise is ~25°C above ambient - well within the –40°C to +150°C operating range. Proper thermal pad soldering is essential to achieve the LMR36006FSC3RNXTQ1's rated thermal performance.

Can the LMR36006FSC3RNXTQ1 operate reliably during automotive cold-crank events?

Yes, the LMR36006FSC3RNXTQ1 supports input voltages as low as 4.2 V and tolerates up to 66 V transiently, making it fully compatible with automotive cold-crank (down to ~5.5 V) and load-dump (up to 60 V) conditions. Its 0.2-V dropout at 0.6-A load ensures the 3.3-V output remains regulated even at 5.5-V input. Combined with AEC-Q100 Grade 1 qualification and 170°C thermal shutdown, the LMR36006FSC3RNXTQ1 maintains uninterrupted operation across full automotive battery voltage extremes.