Analog Devices Inc. LTC3388IMSE-1#TRPBF

Overview

LTC3388IMSE-1#TRPBF from Analog Devices (formerly Linear Technology) is a 20V-input, 50mA synchronous step-down DC/DC converter with nanopower quiescent current, internal high-side PMOS and low-side NMOS switches, and pin-selectable 1.2V/1.5V/1.8V/2.5V outputs. It operates across 2.7V–20V input, draws only 720nA at no load (VIN = 4V), and maintains regulation via hysteretic sleep-mode control-ideal for battery-backed keep-alive rails in portable instrumentation.

For engineers reviewing the LTC3388IMSE-1#TRPBF datasheet, LTC3388IMSE-1#TRPBF pinout, LTC3388IMSE-1#TRPBF application, or LTC3388IMSE-1#TRPBF equivalent, key selection criteria include ultralow IQ in regulation, UVLO threshold (2.3V), standby mode capability, PGOOD open-drain signaling, and precise output voltage selection via D0/D1 logic pins.

Technical Context

The LTC3388IMSE-1#TRPBF implements a hysteretic synchronous buck topology with internal rail generation (CAP at VIN–4.8V, VIN2 at 4.6V), enabling gate drive without external bias supplies. Sleep-state operation uses a low-power comparator to monitor VOUT against ±8mV hysteresis around the selected output voltage, minimizing switching losses at light loads.

It integrates undervoltage lockout (UVLO rising/falling thresholds of 2.3V/2.5V), standby mode that disables buck switching while preserving PGOOD and sleep monitoring, and a power-good comparator with 83%–92% VOUT threshold detection. Output voltage is set by D0/D1 logic levels referenced to VIN2, not GND or VIN.

Key Specifications

Pinout & Package

Package: 10-Lead Plastic MSOP (MSE) with exposed thermal pad (Pin 11 = GND), rated for –40°C to +125°C junction temperature. θJA = 45°C/W, θJC = 10°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar nanopower step-down regulator applications.

Compared with TPS62840DRVR and MAX17651ATB+T, the LTC3388IMSE-1#TRPBF uniquely balances 20V input tolerance, 720nA IQ, pin-selectable outputs, and integrated UVLO - making it optimal for long-life, wide-input, fixed-voltage embedded power rails where simplicity and reliability outweigh programmability or extreme IQ minimization.

Availability

LTC3388IMSE-1#TRPBF is available at Aetrix Electronics and suitable for IoT sensor node power, industrial PLC keep-alive rails, portable medical diagnostic devices, and low-power industrial data loggers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LTC3388IMSE-1#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 continues its legacy of high-performance analog, power management, and signal conditioning ICs for demanding industrial, automotive, and communications applications.

The LTC3388IMSE-1#TRPBF belongs to Linear's nanopower DC/DC converter product line, engineered specifically for ultra-low-quiescent-current applications where battery longevity, input voltage flexibility, and minimal external components are critical design constraints.

FAQ

What is the maximum input voltage rating for the LTC3388IMSE-1#TRPBF?

The LTC3388IMSE-1#TRPBF has an absolute maximum input voltage rating of 22V, with recommended continuous operation up to 20V. Exceeding 22V may cause permanent damage. The device maintains regulation and ultralow IQ across its full 2.7V–20V operating range, making it suitable for unregulated 12V and 19V adapter inputs.

How does the LTC3388IMSE-1#TRPBF achieve 720nA quiescent current?

The LTC3388IMSE-1#TRPBF achieves 720nA typical input quiescent current through a combination of hysteretic sleep-mode control, optimized internal rail generation (CAP and VIN2), and shutdown of non-essential circuitry-including the PGOOD comparator-during sleep. This architecture minimizes static current while preserving fast wake-up response to load transients.

Can the output voltage of the LTC3388IMSE-1#TRPBF be changed dynamically during operation?

Yes, the LTC3388IMSE-1#TRPBF supports dynamic output voltage reconfiguration via D0 and D1 pins while in regulation. When transitioning to a higher output voltage, PGOOD will go low until the new regulation point is reached; when transitioning lower, PGOOD remains asserted. This allows runtime adaptation in multi-rail systems without power cycling.

What is the role of the CAP and VIN2 pins on the LTC3388IMSE-1#TRPBF?

CAP (Pin 3) provides the gate drive voltage for the internal high-side PMOS switch (regulated at VIN – 4.8V), while VIN2 (Pin 7) supplies the gate drive for the low-side NMOS and serves as the logic reference for EN, STBY, D0, and D1 (regulated at 4.6V). Neither pin is intended as a system supply rail; each requires dedicated bypass capacitors (1µF and 4.7µF respectively) to sustain switching energy demands.

Does the LTC3388IMSE-1#TRPBF require external compensation components?

No, the LTC3388IMSE-1#TRPBF uses a hysteretic control architecture that eliminates the need for external compensation networks. Stability is inherent to the topology, and regulation is maintained with standard ceramic output capacitors (≥10µF). This simplifies layout, reduces BOM count, and improves reliability in space-constrained designs.