Texas Instruments LM2623MMX

Overview

LM2623MMX from Texas Instruments is a gated-oscillator-based DC-DC boost converter IC designed for low-input-voltage battery systems. It operates from 0.8 V to 14 V input, delivers adjustable output from 1.24 V to 14 V, supports up to 2 MHz switching frequency, integrates a 0.17 Ω N-channel MOSFET, and achieves up to 90% efficiency in handheld power management applications.

For engineers reviewing the LM2623MMX datasheet, LM2623MMX pinout, LM2623MMX application, or LM2623MMX equivalent, this page provides verified technical context, validated pin functions, confirmed operating parameters (including 1.1 V start-up, <2.5 µA shutdown current, and 80 µA typical operating current), and real-world implementation guidance for compact, high-efficiency boost designs.

Technical Context

The LM2623MMX implements a pulse-frequency-modulated (PFM) gated-oscillator control scheme with cycle-by-cycle current limiting and thermal shutdown. Its oscillator frequency (300 kHz–2 MHz) is resistor-programmable via the FREQ pin, while duty cycle adaptation is enabled through external RC networks including the C3 capacitor on the FREQ node.

It features dual ground paths-PGND (pins 2,3 in WSON) for high-current switching return and SGND (pin 9) for precision feedback reference-and bootstrapped VDD operation enabling regulation down to 0.8 V after startup from as low as 1.1 V. The internal 0.17 Ω MOSFET switch and integrated current limit (1.2 A typical for LM2623 variant) define its load capability at low output voltages.

Key Specifications

Pinout & Package

LM2623MMX is packaged in an 8-pin VSSOP (DGK) with 3.00 mm × 3.00 mm body size and 1.09-mm height - half the footprint of standard SOIC-8. Thermal performance is characterized by R_θJA = 152.5°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2623MMX, LM2622MMX offers higher current headroom but sacrifices adaptive duty cycle control, while LM2733YMF/NOPB trades configurability for integration and layout simplicity - making LM2623MMX optimal when fine-grained efficiency tuning across varying input conditions is critical.

Availability

LM2623MMX is available at Aetrix Electronics and suitable for handheld instrumentation, portable display power, and flash memory programming applications requiring stable component supply, long-lifecycle support, and consistent parametric performance across production batches.

Supply support for LM2623MMX 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 battery-efficient power conversion ICs.

The LM2623 belongs to TI's general-purpose boost converter product line, engineered specifically for ultra-low-input-voltage operation in space-constrained portable electronics where startup reliability and wide-load-efficiency are critical.

FAQ

What is the minimum input voltage required for LM2623MMX to start up?

The LM2623MMX starts up from a minimum input voltage of 1.1 V. This allows it to initiate regulation even from deeply discharged single-cell or two-cell alkaline batteries. Once started, the device sustains operation down to 0.8 V input by bootstrapping its internal VDD supply from the regulated output, making LM2623MMX especially effective in long-life portable applications.

How does the FREQ pin on LM2623MMX affect switching behavior?

The FREQ pin on LM2623MMX sets the oscillator frequency (300 kHz–2 MHz) via an external resistor and enables duty cycle adaptation using an external capacitor (C3). Unlike fixed-frequency converters, LM2623MMX uses this RC network to implement ratio-adaptive gated-oscillator control - dynamically adjusting duty cycle in response to input/output voltage changes to maintain high efficiency across varying battery states.

Can LM2623MMX operate with a single alkaline cell?

Yes, LM2623MMX can operate with a single alkaline cell. Its 1.1 V start-up voltage and ability to regulate down to 0.8 V input after startup make it compatible with the full discharge curve of a 1.5 V alkaline cell (1.5 V → 0.8 V). When paired with appropriate output resistors and a Schottky diode, LM2623MMX reliably generates 3.3 V or 5 V from one cell for low-power microcontrollers or sensors.

What is the purpose of having separate PGND and SGND pins on LM2623MMX?

LM2623MMX separates PGND (pins 2,3) and SGND (pin 6) to isolate high-current switching return paths from sensitive analog reference nodes. PGND carries pulsed inductor current and MOSFET switching return, while SGND serves as the quiet ground reference for FB, EN, and internal error amplifiers. This separation prevents ground bounce from degrading output voltage accuracy and improves stability in noisy portable environments.

Is LM2623MMX pin-compatible with LM2623MFX or other variants?

No, LM2623MMX (8-pin VSSOP) is not pin-compatible with LM2623MFX, which uses a 14-pin WSON package. While both share identical functional pin definitions (e.g., EN, FB, SW), their physical layouts differ significantly - LM2623MFX has dual PGND and SW pins plus a thermal DAP pad, whereas LM2623MMX consolidates those functions into fewer pins. PCB layout and thermal design must be re-validated when substituting between these packages.