Texas Instruments LM2736YMKX

Overview

LM2736YMKX from Texas Instruments is a monolithic, current-mode PWM step-down DC-DC regulator in a 6-pin Thin SOT package. It delivers up to 750 mA output current with 550 kHz fixed switching frequency, 1.25 V internal reference (±2%), and 350 mΩ NMOS switch - designed for compact point-of-load regulation in space-constrained USB-powered devices and notebook computers.

For engineers reviewing the LM2736YMKX datasheet, LM2736YMKX pinout, LM2736YMKX application, or LM2736YMKX equivalent, key selection considerations include its 3.0–18 V input range, 1.25–16 V adjustable output, 30 nA shutdown current, thermal shutdown protection, and internal soft-start - all critical for battery-powered and thermally sensitive embedded power rails.

Technical Context

The LM2736YMKX implements constant-frequency current-mode control with internal compensation, enabling stable regulation across wide load and line variations without external loop components. Its 13 ns minimum on-time supports high duty-cycle operation down to 1.25 V output even at 18 V input.

It integrates undervoltage lockout (2.74 V turn-on, 2.3 V turn-off with 440 mV hysteresis), cycle-by-cycle current limiting (1.5 A typical), overvoltage protection (10% above V_FB), and thermal shutdown (165°C trip, 150°C recovery) - all operating autonomously without host intervention.

Key Specifications

Pinout & Package

LM2736YMKX uses a 6-pin Thin SOT (DDC) package measuring 2.90 mm × 1.60 mm, optimized for high-density layouts and thermal performance on 2- or 4-layer boards.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down regulator applications.

Compared with LM2736XMKX and TPS62231DRVR, the LM2736YMKX uniquely balances wide 3–18 V input compatibility, 750 mA capability, and robust protection features - making it the preferred choice for industrial and battery-backed applications where reliability across voltage extremes is non-negotiable.

Availability

LM2736YMKX is available at Aetrix Electronics and suitable for USB-powered devices, notebook computer I/O rails, HDD core power supplies, and DSL modem signal processing requiring stable component supply and long-term production continuity.

Supply support for LM2736YMKX 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 power management technologies, with decades of expertise in high-reliability DC-DC conversion.

The LM2736YMKX belongs to TI's Thin SOT DC-DC regulator family, engineered specifically for space-constrained, battery-sensitive applications demanding high power density and autonomous fault protection.

FAQ

What is the recommended input capacitor for LM2736YMKX?

The LM2736YMKX requires a minimum 10 µF ceramic input capacitor rated for the full input voltage range (e.g., 6.3 V X5R/X7R). For inputs below 6 V, a 4.7 µF capacitor may suffice. The capacitor must have low ESL - surface-mount MLCCs in 0805 or larger case sizes are strongly preferred to handle high-frequency ripple current and prevent instability. A 10 µF, 6.3 V, X5R capacitor such as TDK C3216X5ROJ106M is a validated choice per TI's reference design for LM2736YMKX.

Does LM2736YMKX require an external catch diode?

Yes, LM2736YMKX requires an external Schottky catch diode (e.g., MBRM110L) connected between SW and GND. Unlike synchronous buck converters, LM2736YMKX uses an internal NMOS switch and relies on this external diode to provide the freewheeling path during the off-time. Diode selection must prioritize low forward voltage (≤0.4 V at 750 mA) and fast recovery to maintain efficiency and prevent reverse recovery losses. The diode's cathode connects to SW, and its anode connects to GND.

How does the BOOST pin function in LM2736YMKX?

The BOOST pin on LM2736YMKX supplies gate drive voltage to the internal NMOS switch. It must be biased 2.5–5.5 V above the SW node using a bootstrap capacitor (typically 0.01 µF) and external diode. During SW low-time, the diode charges the capacitor from VIN or VOUT; during SW high-time, the capacitor provides elevated gate voltage to fully enhance the NMOS. Insufficient BOOST voltage causes increased R_DS(on), reduced output current capability, and thermal stress - so proper bootstrap layout and capacitor selection are essential for reliable 750 mA operation of LM2736YMKX.

Can LM2736YMKX operate with a 2.5 V input?

No, LM2736YMKX cannot operate reliably with a 2.5 V input. Its undervoltage lockout (UVLO) turns on only when VIN exceeds 2.74 V (typical), and the device ceases regulation when VIN falls below 2.3 V. At 2.5 V, the IC remains in UVLO state - no switching occurs, and the output stays unregulated. For sub-3 V applications, consider alternatives like TPS62231 (2.05 V min) or redesign the front-end to ensure VIN ≥3.0 V across all operating conditions for stable LM2736YMKX functionality.

What is the maximum achievable output voltage with LM2736YMKX?

The LM2736YMKX supports an adjustable output voltage range of 1.25 V to 16 V, set by the external resistor divider on the FB pin. The upper limit is constrained by the absolute maximum ratings: SW voltage must remain ≤22 V, and BOOST-to-SW differential must stay ≤5.5 V. In practice, with VIN = 18 V, the highest stable output is 16 V - verified in TI's datasheet electrical characteristics table and confirmed in typical application circuits. Exceeding 16 V risks violating internal comparator headroom and compromising regulation accuracy of LM2736YMKX.