Analog Devices Inc. LTC1514IS8-3.3#TRPBF

Overview

LTC1514IS8-3.3#TRPBF from Analog Devices (formerly Linear Technology) is a micropower switched-capacitor DC/DC converter that regulates 3.3V output via step-up or step-down operation across 2V–8V input, delivering up to 50mA with ±4% regulation, 650kHz switching, and integrated low-battery comparator-used in battery-backed smart card readers and handheld instruments.

For engineers reviewing the LTC1514IS8-3.3#TRPBF datasheet, LTC1514IS8-3.3#TRPBF pinout, LTC1514IS8-3.3#TRPBF application, or LTC1514IS8-3.3#TRPBF equivalent, key selection criteria include input voltage range compatibility, shutdown current (10µA), soft-start timing (4ms), LBI comparator trip point (1.145V), and SO-8 thermal performance (θ_JA = 110°C/W).

Technical Context

The LTC1514IS8-3.3#TRPBF employs a dual-mode charge pump architecture that automatically selects step-up (voltage doubler) or step-down (gated switch) operation based on VIN–VOUT differential, enabling stable 3.3V regulation across 2V–8V input without inductor. Internal hysteresis-driven burst-mode control maintains regulation while limiting quiescent current to 60µA.

Its uncommitted open-drain LBO comparator remains active during shutdown, referenced to a 1.145V internal threshold with ±3% accuracy and <50nA input bias, allowing external battery monitoring without additional circuitry. Protection includes short-circuit current limiting (12mA typ) and thermal shutdown at ~150°C.

Key Specifications

Pinout & Package

Package: 8-lead plastic SO-8 (narrow, 0.150" width), θ_JA = 110°C/W, RoHS-compliant, tape-and-reel (#TRPBF).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar switched-capacitor DC/DC converter applications.

Compared with LTC1514CS8-3.3, the LTC1514IS8-3.3#TRPBF guarantees operation down to –40°C and supports higher ambient reliability; versus LTC1515IS8-3.3, it omits POR functionality to reduce complexity and cost where system-level reset management already exists.

Availability

LTC1514IS8-3.3#TRPBF is available at Aetrix Electronics and suitable for battery-operated equipment, smart card readers, and handheld instruments requiring stable component supply with industrial temperature support and long-term lifecycle assurance.

Supply support for LTC1514IS8-3.3#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 precision analog and power management portfolio with rigorous qualification standards.

The LTC1514 series was designed for ultra-low-power, inductorless DC/DC conversion in space-constrained, battery-sensitive applications-emphasizing micropower operation, wide input range, and integrated supervision.

FAQ

What is the maximum input voltage rating for the LTC1514IS8-3.3#TRPBF?

The LTC1514IS8-3.3#TRPBF has an absolute maximum VIN rating of 12V, but its specified operating range is 2.0V to 8.0V for the -3.3V version. Exceeding 8V may cause increased output ripple and reduced efficiency; the datasheet explicitly recommends 22µF COUT for VIN > 8V-though operation above 8V is outside guaranteed specification for LTC1514IS8-3.3#TRPBF.

Does the LTC1514IS8-3.3#TRPBF require an inductor?

No, the LTC1514IS8-3.3#TRPBF uses a switched-capacitor (charge pump) topology and requires only three external capacitors: one 0.22µF flying capacitor (C1) and two ≥10µF low-ESR bypass capacitors (CIN and COUT). This eliminates magnetic components, reducing EMI and board area versus inductive DC/DC converters.

How does the low-battery comparator function in shutdown mode for the LTC1514IS8-3.3#TRPBF?

The LBI input and LBO output remain fully functional during shutdown: the internal 1.145V reference stays active, continuously comparing LBI voltage to threshold. When LBI falls below 1.145V, LBO pulls low-even with SHDN = 0V-enabling battery cutoff before deep discharge without waking the main system.

What is the purpose of the soft-start feature in the LTC1514IS8-3.3#TRPBF?

The soft-start circuit in the LTC1514IS8-3.3#TRPBF controls the rate at which VOUT ramps from 0V to 3.3V, limiting inrush current to ~12.5mA into a 10µF output capacitor. This prevents input supply sag, avoids false resets in downstream logic, and reduces stress on flying and output capacitors during power-up or exit from shutdown.

Can the LTC1514IS8-3.3#TRPBF be used with lithium iron phosphate (LiFePO₄) batteries?

Yes-the LTC1514IS8-3.3#TRPBF supports 2.0V–8.0V input, matching the 2.5V–3.65V discharge curve of single-cell LiFePO₄. Its 60µA quiescent current and 10µA shutdown current maximize runtime, while ±4% regulation ensures reliable 3.3V operation across the full battery voltage range without external compensation.