Analog Devices Inc. LTC1682IMS8-5#TRPBF

Overview

LTC1682IMS8-5#TRPBF from Analog Devices (formerly Linear Technology) is a fixed 5V, low-noise charge pump doubler with integrated LDO regulator in an 8-pin MSOP package. It accepts 2.7V–4.4V input, delivers up to 50mA regulated output with 64µV_RMS noise (10Hz–100kHz), and features 550kHz switching frequency, 150µA operating current, and thermal/short-circuit protection - designed for powering VCOs in cellular radios and wireless PCMCIA cards.

For engineers reviewing the LTC1682IMS8-5#TRPBF datasheet, LTC1682IMS8-5#TRPBF pinout, LTC1682IMS8-5#TRPBF application, or LTC1682IMS8-5#TRPBF equivalent, key selection criteria include its fixed 5V output, MSOP-8 footprint, 64µV_RMS noise performance at 10Hz–100kHz, shutdown current <5µA, and compatibility with ceramic capacitors only - no inductors required.

Technical Context

The LTC1682IMS8-5#TRPBF integrates a switched-capacitor voltage doubler and a low-dropout linear regulator in a single die. The doubler generates ~2×VIN at CPO, which feeds the LDO stage; the LDO provides ripple-rejected, fixed 5V output with 50mV dropout at 10mA load. Its Burst Mode operation activates below 100µA load to reduce quiescent current while trading off slight noise increase.

Internal protection includes thermal shutdown (>150°C junction), current limiting, and LDO disable logic that disconnects VOUT when CPO falls below 1.45×VIN. Pin 3 functions as FILT (not FB), requiring a 1nF capacitor to ground for optimal reference filtering and noise reduction - a design distinction from the adjustable LTC1682 variant.

Key Specifications

Pinout & Package

Package: 8-pin MSOP (3mm × 3mm, 0.65mm pitch), RoHS-compliant, moisture-sensitive level 1. Thermal pad not present; GND (Pin 4) serves as primary heat path to PCB copper.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise charge pump regulator applications.

Compared with LTC1682IMS8-3.3#TRPBF, the LTC1682IMS8-5#TRPBF offers higher output voltage for 5V-tolerant RF ICs but slightly higher dropout; versus LT3467EMS8#TRPBF, it trades current capability for superior noise performance and integration - making it optimal for VCO bias where spectral purity is non-negotiable.

Availability

LTC1682IMS8-5#TRPBF is available at Aetrix Electronics and suitable for cellular phone VCO supplies, wireless PCMCIA card power, and portable medical instrument sensors requiring stable component supply, long-term lifecycle support, and guaranteed RoHS compliance.

Supply support for LTC1682IMS8-5#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 continuity, documentation, and technical support for all Linear legacy parts including the LTC series.

The LTC1682IMS8-5#TRPBF belongs to Linear's precision low-noise power management family, engineered specifically for RF and analog signal chain applications where supply-induced phase noise and ripple degrade system-level performance.

FAQ

What is the minimum input voltage required for stable 5V output from the LTC1682IMS8-5#TRPBF?

The LTC1682IMS8-5#TRPBF requires a minimum input voltage of 2.7V to guarantee 5.0V ±100mV output across temperature and load. Below 2.7V, regulation degrades due to LDO dropout and insufficient CPO headroom; the datasheet specifies 2.7V as the lower limit for the -5 variant to maintain 5V accuracy at 10mA load and –40°C to +85°C.

Can the LTC1682IMS8-5#TRPBF operate without the 1nF capacitor on the FILT pin?

No - the 1nF capacitor from FILT (Pin 3) to GND is mandatory for the LTC1682IMS8-5#TRPBF to achieve its specified 64µV_RMS output noise. Omitting it increases noise by >30% and destabilizes the internal reference, causing VOUT drift and reduced load regulation. This capacitor filters the bandgap reference and is not optional per the datasheet's "TYPICAL APPLICATION" and "Capacitor Selection" sections.

Does the LTC1682IMS8-5#TRPBF require external compensation components?

No - the LTC1682IMS8-5#TRPBF is internally compensated and stable with only a ≥2µF low-ESR ceramic capacitor on VOUT (Pin 1). The LDO does not require external RC networks or feedforward capacitors. Stability is verified across all operating conditions, including worst-case ESR and capacitance tolerances, eliminating design iteration for loop compensation.

How does the LTC1682IMS8-5#TRPBF behave during startup and shutdown?

At startup, the LTC1682IMS8-5#TRPBF holds VOUT disabled until CPO reaches 1.75×VIN; then the LDO engages. During shutdown (SHDN <0.4V), VOUT is actively pulled to GND via a 100Ω switch, CPO goes high-impedance, and supply current drops to 1µA. Enable-to-shutdown timing is <2ms, and VOUT settles within 2ms after enable - confirmed in Figure G05/G06.

Is the LTC1682IMS8-5#TRPBF pin-compatible with the LTC1682CMS8-5#TRPBF?

Yes - the LTC1682IMS8-5#TRPBF and LTC1682CMS8-5#TRPBF share identical pinout, package (MSOP-8), and electrical specifications; the only difference is temperature grade: I-grade (-40°C to +85°C) vs. C-grade (0°C to +70°C). Layout, BOM, and firmware are fully interchangeable; no PCB changes are required when upgrading from commercial to industrial temperature range.