Texas Instruments LM536253QRNLTQ1

Overview

LM536253QRNLTQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive synchronous buck DC-DC converter delivering a fixed 3.3-V output at up to 2.5-A load, operating from 3.9 V to 36 V input with 2.1-MHz switching frequency, ±1% output voltage tolerance over –40°C to +125°C junction temperature, and integrated RESET output - used in instrument clusters and telematics power rails.

For engineers reviewing the LM536253QRNLTQ1 datasheet, LM536253QRNLTQ1 pinout, LM536253QRNLTQ1 application, or LM536253QRNLTQ1 equivalent, key selection considerations include its 3.3-V fixed output, 2.5-A current rating, wettable-flank VQFN-22 package, spread-spectrum EMI reduction, and automotive-grade thermal performance up to +150°C junction.

Technical Context

The LM536253QRNLTQ1 employs peak-current-mode control with adaptive frequency spreading to maintain regulation down to 300-mV dropout at full load while preserving 2.1-MHz operation across wide VIN–VOUT ratios - enabling 18-V-to-3.3-V conversion without duty-cycle limitation. Its flip-chip HotRod QFN package minimizes parasitic inductance, reducing switch-node ringing and radiated EMI.

It integrates internal compensation, soft-start, thermal shutdown, UVLO, and a filtered open-drain RESET output with 3-ms release timer and ±3% hysteresis relative to output voltage - eliminating external supervision circuitry. Pin-selectable forced PWM mode disables light-load diode emulation for constant-frequency operation.

Key Specifications

Pinout & Package

LM536253QRNLTQ1 uses a 5.0-mm × 4.0-mm VQFN-HR (RNL) 22-pin package with wettable flanks for automated optical solder-joint inspection. Thermal resistance: R_θJA = 29.4°C/W, R_θJC(bot) = 2.4°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM536353QRNLTQ1 and TPS543320RTWR, LM536253QRNLTQ1 offers optimal balance of automotive qualification, integrated RESET, and 2.5-A capability in a compact wettable-flank package - making it ideal for cost-sensitive, space-constrained telematics and cluster designs where full 3.5-A headroom is unnecessary.

Availability

LM536253QRNLTQ1 is available at Aetrix Electronics and suitable for telematics control units, instrument clusters, and automotive head units requiring stable component supply, AEC-Q100 compliance, and long-term automotive lifecycle support.

Supply support for LM536253QRNLTQ1 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 ICs, with decades of automotive qualification expertise and broad power management portfolio.

LM536253QRNLTQ1 belongs to TI's automotive-qualified DC-DC converter family designed specifically for demanding 12-V battery systems - emphasizing low EMI, high thermal resilience, and integration to reduce system size and cost in infotainment and body electronics.

FAQ

What is the maximum input voltage rating for LM536253QRNLTQ1, and how does it handle transients?

The LM536253QRNLTQ1 has an absolute maximum input voltage rating of 40 V, with transient tolerance up to 42 V for ≤500 ms at ≤0.01% duty cycle. This allows safe operation during automotive load-dump events without external TVS clamping in many designs. The device's internal protection circuits remain functional across its full –40°C to +150°C junction temperature range, and LM536253QRNLTQ1 maintains regulation integrity even under these stressed conditions per AEC-Q100 stress testing protocols.

Does LM536253QRNLTQ1 require external feedback resistors for its 3.3-V output?

No, LM536253QRNLTQ1 is a fixed-output variant with internal resistor divider connected to the FB pin, so no external resistors are needed. This eliminates associated tolerance errors, layout sensitivity, and board space - simplifying design and improving long-term output accuracy. The internal reference is trimmed to ±1% over –40°C to +125°C junction temperature, and LM536253QRNLTQ1 maintains this specification without calibration or trimming components.

How does the RESET output of LM536253QRNLTQ1 behave during startup and fault conditions?

The LM536253QRNLTQ1 RESET output is an open-drain signal that remains low until the output reaches 96–110% of nominal 3.3 V and remains stable for ≥3 ms. It asserts low again during EN deactivation, input UVLO, thermal shutdown, or output overvoltage. The internal 12–45 µs glitch filter prevents false triggering from noise. For proper operation, LM536253QRNLTQ1 requires an external pull-up resistor to a valid logic voltage (e.g., 3.3 V or 5 V).

Can LM536253QRNLTQ1 operate with input voltage below 3.9 V, and what is the minimum functional input?

Yes - LM536253QRNLTQ1 supports minimum input voltage of 3.55 V (typical) for full functionality at 1.5-A load after startup, and 3.9 V at full 2.5-A load. Its advanced frequency-spreading architecture enables 98% maximum duty cycle, allowing regulation with only 300-mV dropout at full load. This extended low-VIN capability makes LM536253QRNLTQ1 suitable for cold-crank scenarios in 12-V automotive systems where battery voltage dips below 6 V.

Is LM536253QRNLTQ1 pin-compatible with other devices in the LM536xx-Q1 family?

Yes, LM536253QRNLTQ1 shares identical pinout, package (VQFN-22 RNL), and footprint with all LM53625-Q1 and LM53635-Q1 variants, including adjustable, 5-V, and spread-spectrum versions. This enables drop-in replacement across output voltage and current options without PCB redesign. However, functional differences - such as current rating, spread-spectrum enable, or FPWM behavior - must be verified in firmware and system validation, as LM536253QRNLTQ1 is optimized for 2.5-A 3.3-V use cases.