Texas Instruments LM2623MM

Overview

LM2623MM from Texas Instruments is a general-purpose, gated-oscillator-based DC-DC boost converter IC designed for battery-powered 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 instrumentation and multi-cell alkaline/Li-ion power rails.

For engineers reviewing the LM2623MM datasheet, LM2623MM pinout, LM2623MM application, or LM2623MM 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, ultra-low 80 µA operating current, and <2.5 µA shutdown current - all critical for low-power portable design validation.

Technical Context

The LM2623MM 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 oscillator frequency and duty cycle are externally programmable via resistor (FREQ pin) and capacitor (C3), supporting ratio-adaptive operation that dynamically adjusts to input/output voltage changes.

It integrates an internal 0.17 Ω N-channel MOSFET switch, peak-current limiting (1.2 A typical for LM2623 variant), thermal shutdown (~160°C), and dual ground separation (PGND and SGND) for noise-sensitive feedback stability. The device starts from 1.1 V and sustains operation down to 0.8 V using bootstrapped VDD derived from output voltage.

Key Specifications

Pinout & Package

LM2623MM is packaged in an 8-pin VSSOP (DGK) package measuring 3.00 mm × 3.00 mm with 1.09-mm height, optimized for space-constrained portable designs. 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 LM2623MM, LM2622MM offers higher current capability in identical packaging, while LM2731YMF trades programmability and noise performance for minimal footprint - making LM2623MM optimal for mid-current, low-noise, battery-life-critical applications requiring design flexibility.

Availability

LM2623MM is available at Aetrix Electronics and suitable for handheld instrumentation, multi-cell alkaline systems, and lithium-ion portable devices requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for LM2623MM 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 for portable electronics.

The LM2623 product line delivers general-purpose, gated-oscillator boost converters optimized for battery-powered applications demanding low start-up voltage, wide input range, and ultra-low quiescent current - targeting consumer, industrial, and medical handheld equipment.

FAQ

What is the minimum input voltage required to start up the LM2623MM?

The LM2623MM starts up from a minimum input voltage of 1.1 V at 25°C, as specified in the Electrical Characteristics table. This enables reliable operation from nearly depleted single-cell alkaline or NiMH batteries. Once started, the device can continue regulating down to 0.8 V input by bootstrapping VDD from the output voltage, ensuring maximum usable battery capacity in the LM2623MM design.

How is the switching frequency programmed on the LM2623MM?

The LM2623MM switching frequency is set by connecting an external resistor between the FREQ pin and VIN. The resistor value determines frequency across a 300 kHz–2 MHz range, per the "Frequency vs VIN" curve in the Typical Characteristics section. No capacitor is required for basic frequency setting - though adding C3 enables duty-cycle adjustment for ratio-adaptive PFM optimization in the LM2623MM application.

Does the LM2623MM require separate power supply for the VDD pin?

No - the LM2623MM VDD pin is internally powered from the output voltage once regulation is established. During startup, the device draws current from VIN to charge VDD until output reaches ~3 V, then transitions to bootstrap operation. For stable performance, VDD must be maintained between 3 V and 5 V; connecting VDD directly to VOUT satisfies this requirement in most LM2623MM implementations.

What is the purpose of having both PGND and SGND pins on the LM2623MM?

The LM2623MM separates PGND (pins 1 and 4 in WSON, pin 1 in VSSOP) and SGND (pin 5 in VSSOP) to isolate high-current switching return paths from sensitive analog feedback signals. PGND carries pulsed inductor current and SW node return, while SGND serves only FB, EN, and FREQ. This separation prevents ground bounce from degrading regulation accuracy - a critical design feature confirmed in the LM2623MM Pin Functions table and Layout Guidelines.

Can the LM2623MM replace the LM2621 in an existing design?

The LM2623MM is not a direct replacement for the LM2621 due to differences in current limit (1.2 A vs. 1.0 A), FREQ pin behavior, and C3 capacitor dependency for duty-cycle control. While pin-compatible in VSSOP-8, the LM2623MM's non-linear duty-cycle programming requires re-optimization of C3 and R3 values. TI explicitly notes the LM2623MM is based on LM2621 but adds programmable duty-cycle functionality - meaning LM2623MM integration requires validation of transient response and current-limit margin in the target LM2623MM application.