Texas Instruments LM2733YMF

Overview

LM2733YMF from Texas Instruments is a 0.6-MHz fixed-frequency current-mode boost converter IC with integrated 40-V/1-A DMOS FET switch, 5-pin SOT-23 package, 2.7–14-V input range, and 1.23-V feedback reference voltage-designed for compact high-voltage local boost regulation in portable power rails.

For engineers reviewing the LM2733YMF datasheet, LM2733YMF pinout, LM2733YMF application, or LM2733YMF equivalent, key selection criteria include switching frequency (0.6 MHz), internal FET R_DS(ON) (650 mΩ max), shutdown current (<1 µA), duty cycle capability (96% max), and thermal performance (R_θJA = 210°C/W) in space-constrained designs.

Technical Context

The LM2733YMF implements peak-current-mode control with cycle-by-cycle current limiting and internal compensation-enabling stable operation without external loop components. Its 0.6-MHz oscillator sets timing for PWM generation, while the FB pin regulates output via a resistive divider referenced to 1.23 V.

Shutdown is logic-level active-low; pulling SHDN below 0.5 V disables switching and reduces quiescent current to 24 nA. The internal 40-V FET supports output voltages up to 40 V, and maximum duty cycle reaches 96% at room temperature-critical for high step-up ratios in low-input applications.

Key Specifications

Pinout & Package

LM2733YMF uses a 5-pin SOT-23 (DBV) package, 2.90 mm × 1.60 mm body size, with exposed pad not electrically connected. Pin 1 is SW (switch node), Pin 2 is GND (common analog/power ground), Pin 3 is FB (feedback input), Pin 4 is SHDN (active-low enable), and Pin 5 is VIN (input supply).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2733XMF and TPS61040DRVR, the LM2733YMF offers optimal balance of thermal performance (210°C/W), 40-V FET headroom, and 0.6-MHz efficiency-making it the preferred choice for 330-mA, 12–30-V boost applications where layout area and heat dissipation are jointly constrained.

Availability

LM2733YMF is available at Aetrix Electronics and suitable for portable medical monitors, handheld test equipment, and battery-powered IoT gateways requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for LM2733YMF 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 delivering analog, embedded processing, and connectivity solutions with focus on reliability, precision, and energy efficiency.

The LM2733 product line delivers high-power-density boost converters for space-constrained portable electronics-designed to replace discrete boost stages with integrated FET, current-mode control, and minimal external components.

FAQ

What is the maximum output voltage achievable with LM2733YMF?

The LM2733YMF supports output voltages up to 40 V, limited by its 40-V internal FET breakdown rating. At 30 V output, it delivers 110 mA typical; at 40 V, ~70 mA-both verified in TI's Figure 23 efficiency curves. Output voltage is set externally via FB divider; ensure Schottky diode (e.g., MBR0540) and output capacitor voltage ratings exceed target V_OUT. The LM2733YMF itself does not regulate beyond its FET's voltage limit.

Does LM2733YMF require external compensation components?

No, the LM2733YMF features an internally compensated current-mode control loop-eliminating the need for external compensation networks. However, the feedforward capacitor C_f (220 pF for "Y" version) is mandatory for stability and must be placed between FB and GND as shown in the typical application circuit. Omitting C_f causes loop oscillation; its value is frequency-specific and differs between LM2733YMF (220 pF) and LM2733XMF (120 pF).

How does shutdown functionality work on LM2733YMF?

The LM2733YMF enters ultra-low-power shutdown when SHDN pin voltage falls below 0.5 V (typical), reducing quiescent current to 24 nA. To activate, connect SHDN to GND through a switch or GPIO; to disable shutdown, tie SHDN directly to VIN-never leave it floating. A pullup resistor (50–100 kΩ to VIN) is recommended if SHDN is driven by an open-drain signal. The LM2733YMF resumes regulation within 100 µs after SHDN rises above 1.5 V.

Can LM2733YMF drive multiple white LEDs in series?

Yes-the LM2733YMF is commonly used to drive 3–6 white LEDs (3.0–3.6 V each) in series from a 3.3–5-V source. For example, six 3.3-V LEDs require ~20 V output; the LM2733YMF delivers 170 mA at 20 V (per Table 1). Use a current-sense resistor in the LED cathode path, referenced to FB, and select a Schottky diode rated ≥25 V (e.g., MBR0530). Efficiency remains >82% at this point, as confirmed in Figure 19.

What is the minimum inductor value recommended for LM2733YMF at 12-V output?

Texas Instruments recommends a 10-µH inductor for 5-V-to-12-V boost with LM2733YMF (see Figure 25 analysis). Lower values (e.g., 4.7 µH) may be used but risk entering discontinuous conduction mode below ~33 mA load-and reduce maximum deliverable current due to higher peak inductor current. The LM2733YMF's 1-A switch limit constrains minimum L: for 12-V output from 3.7-V input, L < 6.8 µH risks hitting current limit before reaching 330-mA typical load. Always verify ripple current (≤30% of average) and thermal rise in final layout.