Texas Instruments LM2623AMMX

Overview

LM2623AMMX 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 A load at low output voltages, features a 0.17 Ω internal N-channel MOSFET, and achieves up to 90% efficiency in handheld power management applications.

For engineers reviewing the LM2623AMMX datasheet, LM2623AMMX pinout, LM2623AMMX application, or LM2623AMMX equivalent, key selection criteria include its 1.1 V start-up voltage, programmable 300 kHz–2 MHz switching frequency via external resistor, PFM regulation mode, 8-pin VSSOP package footprint, and shutdown quiescent current under 2.5 µA - all critical for ultra-low-power portable designs.

Technical Context

The LM2623AMMX implements a gated-oscillator control scheme with pulse frequency modulation (PFM), enabling high efficiency across wide load ranges by skipping switching cycles upon reaching regulation. Its on/off regulation avoids continuous switching during light loads, minimizing quiescent current (80 µA typical operating, <2.5 µA shutdown).

It integrates an internal 0.17 Ω N-channel MOSFET switch, cycle-by-cycle peak current limit (1.2 A typical for LM2623 variant), thermal shutdown (~160°C), and dual ground pins (PGND and SGND) for noise isolation. The FREQ pin accepts an external resistor to set switching frequency, while FB pin monitors output via resistive divider for precise 1.24 V reference-based regulation.

Key Specifications

Pinout & Package

LM2623AMMX is housed in an 8-pin VSSOP (DGK) package measuring 3.00 mm × 3.00 mm with 1.09-mm height - half the footprint of standard SOIC-8 and optimized for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2623AMMX, LM2623MMX offers identical form and function but reduced current headroom, while LM2731YMF/NOPB trades PFM efficiency and programmability for smaller size and fixed-frequency predictability - making LM2623AMMX optimal for high-efficiency, variable-load, battery-critical applications.

Availability

LM2623AMMX is available at Aetrix Electronics and suitable for camera flash power supplies, white LED backlight drivers, handheld instrument power rails, and flash memory programming supplies requiring stable component supply, long-lifecycle support, and TI-qualified production-grade availability.

Supply support for LM2623AMMX 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 product line was engineered specifically for ultra-low-voltage, high-efficiency boost conversion in portable electronics - emphasizing minimal start-up voltage, adaptive PFM control, and integrated power switches to reduce system size and cost.

FAQ

What is the minimum input voltage required for LM2623AMMX to start up?

The LM2623AMMX starts up from as low as 1.1 V, enabling reliable operation from nearly depleted 1–2 cell alkaline, NiMH, or Li-ion batteries. Once started, it continues regulating down to 0.8 V input by bootstrapping VDD from the output. This start-up threshold is confirmed in the Electrical Characteristics table (VDD_ST = 1.1 V, TYP) and applies specifically to the LM2623A variant.

Does LM2623AMMX support adjustable switching frequency, and how is it configured?

Yes, LM2623AMMX supports programmable switching frequency from 300 kHz to 2 MHz via an external resistor connected between VIN and the FREQ pin (Pin 5). The resistor value determines frequency per Figure 3 in the datasheet - e.g., 300 kΩ yields ~300 kHz, 100 kΩ yields ~600 kHz. No capacitor is required for basic frequency setting; C3 is used separately for duty-cycle tuning.

What is the difference between LM2623AMMX and LM2623MMX?

LM2623AMMX and LM2623MMX share the same 8-pin VSSOP package, pinout, and core functionality, but differ in peak switch current limit: LM2623AMMX is rated for 2.85 A (TYP), while LM2623MMX is rated for 1.2 A (TYP). This makes LM2623AMMX suitable for higher-pulse-load applications like camera flash, whereas LM2623MMX targets lower-current continuous loads.

Can LM2623AMMX operate with a single 1.5 V alkaline cell?

Yes, LM2623AMMX can start from 1.1 V and regulate continuously down to 0.8 V, making it fully compatible with single 1.5 V alkaline cells - even as voltage drops to 0.9 V or lower during discharge. Its gated-oscillator PFM architecture maintains high efficiency across this wide input range, unlike fixed-frequency boosters that suffer efficiency collapse at low VIN.

How is output voltage set on LM2623AMMX, and what is the reference voltage?

LM2623AMMX uses a precision 1.24 V internal reference at the FB pin to set output voltage. The output is adjusted via an external resistive divider (RF1 and RF2) where VOUT = 1.24 V × (1 + RF1/RF2). RF2 is typically 50–100 kΩ; RF1 is calculated accordingly. This reference exhibits ±2.2% variation over −40°C to 85°C, ensuring stable regulation across operating conditions.