Texas Instruments LM536033QPWPTQ1

Overview

LM536033QPWPTQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive synchronous buck DC/DC converter delivering up to 3 A at 3.3 V output from 3.5 V–36 V input, featuring 2.1 MHz fixed switching frequency, ±2% output voltage tolerance, and integrated open-drain RESET with 2 ms assertion delay and 25 µs glitch filter - deployed in instrument clusters and ADAS power rails.

For engineers reviewing the LM536033QPWPTQ1 datasheet, LM536033QPWPTQ1 pinout, LM536033QPWPTQ1 application, or LM536033QPWPTQ1 equivalent, key selection criteria include its 3.3 V fixed-output configuration, HTSSOP-16 thermal performance (R_θJA = 42.5°C/W), forced PWM mode control (FPWM), and automotive-grade transient tolerance (42 V for ≤500 ms).

Technical Context

The LM536033QPWPTQ1 implements current-mode control with valley-current limiting (ILS = 3.0–4.3 A) and high-side peak-current protection (IHS = 4.5–6.2 A), enabling robust overload and short-circuit response via hiccup-mode recovery (5.5 ms off-time). Its adaptive light-load operation transitions seamlessly between PFM and PWM modes, maintaining 24 µA no-load quiescent current while sustaining regulation down to 3.9 V input at full 3 A load.

Internal 3.15 V VCC regulator powers control circuitry; BIAS pin connects directly to VOUT for improved line regulation; SYNC input accepts 1.9–2.3 MHz external clock; FPWM pin forces continuous conduction regardless of load. The RESET comparator tracks VOUT with 94.5–96.5% falling threshold and 105–110% rising threshold, referenced to the same 1.0 V internal bandgap as the feedback loop.

Key Specifications

Pinout & Package

LM536033QPWPTQ1 uses a thermally enhanced 16-pin HTSSOP package (5.00 mm × 4.40 mm × 1.00 mm) with exposed thermal pad (EP) connected to PGND for optimal heat dissipation in automotive PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM536023QPWPTQ1, LM536033QPWPTQ1 delivers higher current headroom and stronger overload protection; versus TPS543320RTWR, it provides AEC-Q100 compliance, wider input range, and embedded power-good signaling - reducing total component count by two in qualified automotive designs.

Availability

LM536033QPWPTQ1 is available at Aetrix Electronics and suitable for automotive instrument clusters, ADAS camera modules, and HUD projection units requiring stable component supply across extended temperature and lifecycle requirements.

Supply support for LM536033QPWPTQ1 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 experience in power management innovation.

The LM5360x-Q1 product line was engineered specifically for automotive power conversion - emphasizing AEC-Q100 reliability, wide-input transient resilience, and integrated system-level functions like RESET to reduce bill-of-materials in safety-critical ECUs.

FAQ

What is the minimum input voltage required for LM536033QPWPTQ1 to regulate a stable 3.3 V output at full 3 A load?

The LM536033QPWPTQ1 requires a minimum input voltage of 3.9 V to maintain ±2% regulation at 3.3 V/3 A output, as verified in the System Characteristics table. Below this, dropout behavior occurs - e.g., at VIN = 3.55 V, regulation holds only at 1 A load. This 3.9 V threshold ensures reliable operation during automotive cold-crank events where battery voltage dips near 3.5 V.

Does LM536033QPWPTQ1 require external feedback resistors to set its 3.3 V output?

No, LM536033QPWPTQ1 does not require external feedback resistors. It is a fixed 3.3 V output variant - the FB pin is internally connected to a precision 1.0 V reference and trimmed output divider. Adding external resistors would disrupt regulation and is explicitly prohibited in the datasheet. The "3" in the part number denotes the 3.3 V fixed option.

How does the RESET function of LM536033QPWPTQ1 differ from a standard power-good signal?

The LM536033QPWPTQ1 RESET uses the same 1.0 V internal reference as the feedback loop, enabling tracking thresholds: falling edge at 94.5–96.5% and rising edge at 105–110% of actual VOUT. Combined with 25 µs glitch filtering and 2 ms assertion delay, this eliminates false triggers during transients - unlike generic supervisors that use independent references and fixed thresholds.

Can LM536033QPWPTQ1 operate with FPWM disabled (pin grounded) in automotive stop-start systems?

Yes - with FPWM grounded, LM536033QPWPTQ1 automatically transitions between PWM (heavy load) and PFM (light load) modes. In stop-start scenarios, this reduces no-load quiescent current to 24 µA, extending battery life during engine-off periods while maintaining fast transient response when load steps occur during restart.

What thermal design guidance applies to LM536033QPWPTQ1's exposed pad (EP) in an automotive PCB?

The EP pad of LM536033QPWPTQ1 must be soldered to a dedicated internal or bottom-layer GND plane using ≥4 thermal vias (0.3 mm diameter, spaced ≤1.2 mm apart) to achieve R_θJC(bot) = 1.1°C/W. TI recommends a minimum 12 mm² copper area under the pad; insufficient thermal relief will cause junction temperatures to exceed 150°C at 3 A load in +85°C ambient.