Analog Devices Inc. LTC3261HMSE#TRPBF

Overview

LTC3261HMSE#TRPBF from Analog Devices (formerly Linear Technology) is a high-voltage, low-quiescent-current inverting charge pump IC designed for bipolar supply generation in industrial and instrumentation systems. It operates from 4.5V to 32V input, delivers up to 100mA output current, regulates to –VIN in constant-frequency mode or –0.94·VIN in Burst Mode®, and features programmable 50kHz–500kHz switching via RT pin - used in portable medical equipment and precision analog biasing.

For engineers reviewing the LTC3261HMSE#TRPBF datasheet, LTC3261HMSE#TRPBF pinout, LTC3261HMSE#TRPBF application, or LTC3261HMSE#TRPBF equivalent, key selection criteria include guaranteed –40°C to 150°C junction temperature operation, exposed-pad MSOP thermal performance, short-circuit/thermal protection behavior, and mode-selectable trade-off between output ripple and quiescent current.

Technical Context

The LTC3261HMSE#TRPBF implements a four-switch flying-capacitor topology with internal logic-controlled phase sequencing. Its dual-mode architecture uses hysteretic burst control (MODE = high) for ultra-low 60µA IQ or open-loop constant-frequency inversion (MODE = low) with fixed 500kHz or resistor-programmable 50kHz–500kHz oscillator.

Thermal protection activates at ~175°C junction temperature, disabling output until cooling to ~165°C; short-circuit current is internally limited to 160mA (typ). The exposed GND pad (Pin 13) is mandatory for thermal integrity and electrical reference, with θ_JA = 40°C/W under specified PCB layout conditions.

Key Specifications

Pinout & Package

The LTC3261HMSE#TRPBF is housed in a thermally enhanced 12-pin MSOP package with an exposed GND pad (Pin 13) that must be soldered to the PCB ground plane for thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar inverting charge pump applications.

Compared with LTC3260IMSE#TRPBF, the LTC3261HMSE#TRPBF offers smaller size and lower component count for single-rail inversion, while LT3467EDD#TRPBF trades inductor dependency for superior efficiency above mid-load - making LTC3261HMSE#TRPBF the optimal choice for space-constrained, wide-input, low-IQ industrial bias generation.

Availability

LTC3261HMSE#TRPBF is available at Aetrix Electronics and suitable for industrial instrumentation, portable medical devices, and high-voltage data acquisition systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LTC3261HMSE#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 full product support, manufacturing, and documentation for the LTC portfolio. Linear Technology was renowned for high-performance analog ICs targeting precision power, signal conditioning, and timing applications.

The LTC3261HMSE#TRPBF belongs to Linear's high-voltage charge pump family, engineered specifically for inductorless bipolar supply generation in harsh-environment instrumentation - emphasizing wide input range, robust protection, and guaranteed high-temperature operation.

FAQ

What is the maximum junction temperature rating for the LTC3261HMSE#TRPBF?

The LTC3261HMSE#TRPBF is guaranteed to operate continuously over a junction temperature range of –40°C to 150°C. This H-grade qualification exceeds standard industrial grades and supports deployment in high-ambient environments such as motor control cabinets or outdoor industrial enclosures. Thermal shutdown activates at ~175°C to prevent permanent damage, with automatic recovery at ~165°C.

How does the MODE pin affect regulation accuracy and output ripple in the LTC3261HMSE#TRPBF?

When MODE = high, the LTC3261HMSE#TRPBF enters Burst Mode® and regulates VOUT to –0.94·VIN with ±1.5% typical tolerance but higher output ripple due to intermittent switching. When MODE = low, it operates in constant-frequency mode with VOUT = –VIN (±3% typical) and significantly lower ripple - making the LTC3261HMSE#TRPBF adaptable to either low-power standby or low-noise active operation.

Can the LTC3261HMSE#TRPBF generate –24V from a 24V input, and what are the practical limitations?

Yes, the LTC3261HMSE#TRPBF can generate –24V from a 24V input in constant-frequency mode (MODE = low). Practical limitations include voltage drop across internal switches and flying capacitor ESR, resulting in VOUT ≈ –(VIN – IOUT·ROL). At 100mA and 500kHz, ROL ≈ 32Ω, so expected VOUT ≈ –20.8V. For tighter regulation, reduce load current or increase f_OSC via RT to lower ROL.

What is the role of the exposed pad (Pin 13) on the LTC3261HMSE#TRPBF, and is it electrically connected?

The exposed pad (Pin 13) on the LTC3261HMSE#TRPBF is electrically connected to GND and serves as the primary thermal conduction path. It must be soldered to a PCB ground plane using ≥6 thermal vias to achieve the specified θ_JA = 40°C/W. Leaving it unconnected degrades thermal performance and may cause premature thermal shutdown under load - a critical requirement for reliable LTC3261HMSE#TRPBF operation.

Does the LTC3261HMSE#TRPBF require external components for basic operation, and which ones are mandatory?

Yes, the LTC3261HMSE#TRPBF requires three mandatory external components: a flying capacitor (CFLY ≥1µF ceramic) between C+ and C– pins, an input bypass capacitor (CIN ≥2µF ceramic) at VIN, and an output capacitor (COUT ≥10µF ceramic) at VOUT. The RT resistor is optional (defaults to 500kHz if omitted), and EN/MODE pull-up/down resistors are optional but recommended for deterministic startup.