Analog Devices Inc. LTC3443EDE#TRPBF

Overview

LTC3443EDE#TRPBF from Analog Devices (formerly Linear Technology) is a high-efficiency, fixed-frequency synchronous buck-boost DC/DC converter capable of regulated output with input voltage above, below, or equal to the output. It delivers up to 1.2A continuous output current from a single Li-ion cell (2.8V–4.2V), operates at 600kHz, features true output disconnect in shutdown, and uses a single inductor without mandatory Schottky diodes. It is designed for portable power rails such as 3.3V in handheld instruments and digital cameras.

For engineers reviewing the LTC3443EDE#TRPBF datasheet, LTC3443EDE#TRPBF pinout, LTC3443EDE#TRPBF application, or LTC3443EDE#TRPBF equivalent, key selection criteria include its buck-boost topology with seamless mode transition, 28μA Burst Mode quiescent current, 12-lead DFN (4mm × 3mm) thermal package, and support for output voltages from 2.4V to 5.25V with ±1.5% feedback accuracy.

Technical Context

The LTC3443EDE#TRPBF implements a four-switch synchronous buck-boost topology with continuous transfer function across buck, buck-boost, and boost regions-enabling stable regulation as input voltage crosses the output level. Its internal control architecture uses a voltage-mode error amplifier (1.22V reference, 90dB gain) and PWM logic with anti-cross-conduction timing to phase NMOS (0.10Ω) and PMOS (0.11Ω) switches.

Operation supports user-selectable modes: Burst Mode (28μA IQ, variable frequency) for ultra-low-load efficiency or fixed-frequency (600kHz, synchronizable up to 1.2MHz) for low-noise performance. Soft-start is integrated via SHDN/SS pin clamping, and protection includes thermal shutdown, 3.2A average current limit, and reverse current limiting (–0.4A).

Key Specifications

Pinout & Package

The LTC3443EDE#TRPBF is housed in a thermally enhanced 12-lead (4mm × 3mm × 0.8mm) plastic DFN package with exposed PGND pad (Pin 13) requiring solder connection to PCB ground for optimal thermal performance (θJA = 43°C/W on 4-layer board).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC3441EDE#TRPBF, the LTC3443EDE#TRPBF delivers lower quiescent current and improved Burst Mode stability; versus TPS63020DSJR, it offers better thermal dissipation in DFN and seamless mode transition-but requires different compensation and layout.

Availability

LTC3443EDE#TRPBF is available at Aetrix Electronics and suitable for handheld instruments, digital cameras, and MP3 players requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature grade (–40°C to 85°C).

Supply support for LTC3443EDE#TRPBF 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

Analog Devices acquired Linear Technology in 2017 and maintains its high-performance power management portfolio with rigorous qualification and long-term support.

The LTC3443EDE#TRPBF belongs to Linear's micropower buck-boost converter family, engineered specifically for single-cell Li-ion systems where input voltage crosses the regulated output-enabling compact, efficient, and reliable portable power rails.

FAQ

What is the minimum input voltage required to start up the LTC3443EDE#TRPBF?

The LTC3443EDE#TRPBF has a guaranteed minimum start-up voltage of 2.4V over the full operating temperature range (–40°C to 85°C), with typical operation beginning at 2.3V. This ensures reliable turn-on across the entire Li-ion discharge curve, including end-of-life battery conditions down to ~2.8V under load.

Does the LTC3443EDE#TRPBF require external Schottky diodes for basic operation?

No, the LTC3443EDE#TRPBF does not require external Schottky diodes for basic operation. Its integrated synchronous MOSFETs eliminate the need for external rectification. However, adding Schottky diodes (e.g., PMEG2010EA) from SW1 to GND and SW2 to VOUT improves peak efficiency by 1–2%, especially at light loads or when VOUT exceeds 4.3V.

How is output voltage adjusted on the LTC3443EDE#TRPBF?

The LTC3443EDE#TRPBF uses a resistor divider from VOUT to GND, with the midpoint connected to the FB pin. The internal 1.22V reference sets VOUT = 1.22V × (1 + R1/R2). For example, setting R1 = 340kΩ and R2 = 15kΩ yields a nominal 3.3V output. Feedback input current is <50nA, minimizing divider error.

What thermal considerations apply to the LTC3443EDE#TRPBF's exposed pad?

Pin 13 (exposed pad) of the LTC3443EDE#TRPBF is electrically and thermally connected to PGND. It must be soldered to a dedicated PCB copper pour tied to system ground. With proper 4-layer board layout, θJA is 43°C/W-enabling 1.2A continuous output at 85°C ambient. Insufficient pad soldering causes thermal derating and potential thermal shutdown.

Can the LTC3443EDE#TRPBF synchronize to an external clock, and what are the requirements?

Yes, the LTC3443EDE#TRPBF can synchronize its 600kHz oscillator using the MODE/SYNC pin. An external clock signal must be 1.38MHz–2.4MHz (twice the desired switching frequency), with pulse width 100ns–2μs. The internal oscillator locks to fSYNC/2, enabling EMI reduction through frequency dithering or alignment with system clocks.