Texas Instruments LM2750SDX-ADJ

Overview

LM2750SDX-ADJ from Texas Instruments is a regulated switched-capacitor boost regulator in a 10-pin WSON (3mm × 3mm) package, delivering adjustable 3.8V–5.2V output with ±4% accuracy. It operates from 2.7V–5.6V input, delivers up to 120mA at VIN ≥ 2.9V, and uses only three external ceramic capacitors. It serves as a low-noise, inductorless power source for Li-ion–powered portable electronics requiring stable 5V rail generation.

For engineers reviewing the LM2750SDX-ADJ datasheet, LM2750SDX-ADJ pinout, LM2750SDX-ADJ application, or LM2750SDX-ADJ equivalent, key selection considerations include its fixed 1.7MHz switching frequency, FB-based output voltage programming, pre-regulation architecture minimizing input ripple, thermal shutdown at 150°C, and 2µA shutdown current - all critical for space-constrained, battery-operated designs.

Technical Context

The LM2750SDX-ADJ implements a two-phase non-overlapping switched-capacitor doubler with internal pre-regulation: input-connected pass-transistor resistance is modulated to regulate VOUT before voltage doubling. Its feedback pin (FB, Pin 3) senses output via external resistor divider (R1/R2), enabling precise 3.8V–5.2V adjustment using VOUT = 1.23V × (1 + R1/R2).

It integrates soft-start (500µs typical turn-on time), overcurrent limiting (300mA typ.), and thermal shutdown (engage at TJ = 150°C, release at 130°C). Input current ripple is minimized by pre-regulation, and output ripple remains low (4mVp-p typical with 10µF COUT, 100mA load) due to high 1.7MHz switching frequency and low-ESR ceramic capacitor compatibility.

Key Specifications

Pinout & Package

LM2750SDX-ADJ is housed in a thermally enhanced 10-pin WSON package (3mm × 3mm, NGY0010A/DSC0010A), featuring an exposed die-attach pad (DAP) for efficient heat dissipation. The package supports standard reflow and requires no derating under typical operating conditions (θJA = 55°C/W on 4-layer board).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar switched-capacitor boost regulator applications.

Compared with LM2750SDX-5.0, the LM2750SDX-ADJ trades pin-compatible simplicity for programmability - enabling one BOM to serve multiple voltage variants. Against MAX8647ETE+T, it offers +20mA output headroom and proven thermal robustness in WSON, but at lower switching frequency.

Availability

LM2750SDX-ADJ is available at Aetrix Electronics and suitable for white LED backlighting, SIM card power, audio amplifier bias, and general-purpose Li-ion-to-5V conversion requiring stable component supply, long-term lifecycle assurance, and consistent parametric performance.

Supply support for LM2750SDX-ADJ 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-efficiency DC-DC conversion.

The LM2750 product line was designed specifically for space-constrained, battery-powered portable electronics needing ultra-low-noise, inductorless 5V generation - targeting display, SIM, and audio subsystems where EMI and PCB area are critical constraints.

FAQ

What output voltage range does the LM2750SDX-ADJ support, and how is it set?

The LM2750SDX-ADJ supports an output voltage range of 3.8V to 5.2V, set externally via a resistor divider connected to the FB pin (Pin 3). The relationship is VOUT = 1.23V × (1 + R1/R2), with R1 + R2 recommended between 15kΩ and 20kΩ. This configuration allows precise tuning without changing the IC, making LM2750SDX-ADJ ideal for multi-voltage platform designs where a single regulator footprint must accommodate varying system rail requirements.

How does the LM2750SDX-ADJ achieve low input current ripple compared to standard charge pumps?

The LM2750SDX-ADJ achieves low input current ripple through its proprietary pre-regulation architecture: it modulates the on-resistance of input-connected switches *before* the voltage-doubling stage, effectively smoothing input current draw. Unlike conventional switched-capacitor doublers that draw pulsed current from VIN, LM2750SDX-ADJ maintains near-constant input current, reducing conducted EMI and eliminating the need for large input filtering. This makes LM2750SDX-ADJ especially suitable for systems where VIN is shared with noise-sensitive RF or audio circuits.

What are the minimum external capacitor requirements for stable operation of the LM2750SDX-ADJ?

For stable operation, the LM2750SDX-ADJ requires three external ceramic capacitors: CIN ≥ 2.2µF (input), COUT ≥ 2.2µF (output), and CFLY = 1.0µF (flying). All must be low-ESR X5R/X7R MLCCs - e.g., TDK C2012X7R1A225K for CIN/COUT and C1608X5R1A105K for CFLY. Using tantalum or electrolytic capacitors is not recommended due to high ESR, which degrades efficiency and increases output ripple. These values ensure regulation across the full 120mA load range and maintain <4mVp-p ripple at 100mA.

Does the LM2750SDX-ADJ include built-in protection features, and how do they function?

Yes, the LM2750SDX-ADJ integrates overcurrent limiting (300mA typical) and thermal shutdown (engages at TJ ≈ 150°C, releases at ≈130°C). During output short-circuit, current limiting clamps IOUT to protect internal switches; sustained limiting triggers thermal shutdown to prevent permanent damage. Both functions operate autonomously without external components. This dual-protection scheme ensures robust operation in consumer devices where accidental shorts or ambient temperature excursions may occur - a key reliability advantage of LM2750SDX-ADJ over discrete charge-pump implementations.

Can the LM2750SDX-ADJ operate down to 2.7V input, and what is its output current capability at that voltage?

Yes, the LM2750SDX-ADJ operates down to 2.7V input, but output current capability is reduced at low VIN: it delivers up to 40mA when 2.7V ≤ VIN ≤ 2.9V, and up to 120mA when VIN ≥ 2.9V. This stepped current profile aligns with Li-ion battery discharge characteristics, ensuring usable power across the full cell voltage range. At 2.7V, the regulator maintains ±4% output accuracy and continues soft-start and shutdown functionality - enabling graceful degradation rather than abrupt failure as the battery depletes. This behavior is fully specified and tested for LM2750SDX-ADJ.