Texas Instruments LM2733YMFX/NOPB

Overview

LM2733YMFX/NOPB 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-designed for compact high-voltage local boost regulation in portable power rails.

For engineers reviewing the LM2733YMFX/NOPB datasheet, LM2733YMFX/NOPB pinout, LM2733YMFX/NOPB application, or LM2733YMFX/NOPB equivalent, key selection criteria include switching frequency (600 kHz), 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 LM2733YMFX/NOPB implements peak-current-mode control with cycle-by-cycle current limiting and internal compensation. Its 0.6-MHz oscillator sets timing for PWM generation, while the FB pin senses output via resistive divider to regulate voltage at 1.23 V ±25 mV over temperature.

Shutdown logic disables the internal FET when SHDN falls below 0.5 V, reducing quiescent current to 24 nA typical. The 40-V drain rating enables output voltages up to 40 V with external Schottky diode and inductor, supporting white LED bias and local 12–30 V boost rails.

Key Specifications

Pinout & Package

LM2733YMFX/NOPB uses a 5-pin SOT-23 (DBV) package, 2.90 mm × 1.60 mm body size, with exposed pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2733YMFX/NOPB, LM2731YMF/NOPB trades 40-V capability for higher current and lower R_DS(ON), while TPS61040DRVR offers integrated soft-start in smaller WSON but sacrifices voltage headroom and current capacity-making LM2733YMFX/NOPB optimal for 20–40 V, 300–330 mA portable boost needs.

Availability

LM2733YMFX/NOPB is available at Aetrix Electronics and suitable for portable phone power rails, white LED backlighting, digital camera flash charging, and industrial sensor local boost requiring stable component supply and long-term production continuity.

Supply support for LM2733YMFX/NOPB 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The LM2733 product line delivers high-power-density boost converters targeting space-constrained portable and battery-operated systems requiring efficient, integrated 0.6-/1.6-MHz DC-DC conversion with minimal external components.

FAQ

What is the maximum output voltage achievable with LM2733YMFX/NOPB?

The LM2733YMFX/NOPB supports output voltages up to 40 V, limited by its 40-V internal FET drain rating and compatible with Schottky diodes like MBR0540. At 30–40 V output, design must account for reduced duty cycle margin and thermal derating-efficiency drops to ~75% at 40 V/110 mA (VIN = 5 V), per TI's Figure 23.

Does LM2733YMFX/NOPB require external compensation components?

LM2733YMFX/NOPB is internally compensated but requires an external feedforward capacitor (C_f) for loop stability. For the "Y" variant (0.6 MHz), TI specifies C_f = 82 pF (R1 = 309 kΩ) per Table 1. Omitting C_f causes oscillation; values deviating >20% from recommended degrade phase margin and transient response.

How does shutdown functionality work on LM2733YMFX/NOPB?

The SHDN pin on LM2733YMFX/NOPB disables the internal FET when pulled below 0.5 V, reducing quiescent current to <1 µA. To enable, tie SHDN to VIN (no pullup needed). Leaving SHDN floating is prohibited-TI recommends a 50–100 kΩ pullup to VIN if external control is unused, per Section 7.4.1.

Can LM2733YMFX/NOPB operate from a 2.7-V input source?

Yes, LM2733YMFX/NOPB operates down to 2.7 V input, per Recommended Operating Conditions. At 2.7 V, R_DS(ON) increases due to reduced gate drive, and maximum duty cycle drops to ~93% (Figure 6), limiting 40-V output capability. Efficiency at 2.7 V/12 V is ~82% (Figure 18), making it viable for single-cell Li-ion discharge endpoints.

What inductor value is recommended for LM2733YMFX/NOPB in a 5-V-to-12-V boost application?

Texas Instruments recommends a 10 µH inductor for 5-V-to-12-V boost with LM2733YMFX/NOPB (Section 8.2.2.9). This value maintains continuous conduction mode above ~33 mA load, minimizes ripple current (176 mA peak-to-peak), and balances size vs. efficiency-achieving >88% efficiency at 330 mA per Figure 18.