Analog Devices Inc. LT1614CMS8#TRPBF

Overview

LT1614CMS8#TRPBF from Analog Devices (formerly Linear Technology) is a fixed-frequency, inverting switching regulator IC designed to generate negative output voltages from low-input sources. It operates from 1V to 6V input, delivers up to –24V output, features 600kHz switching, 500mA internal NPN switch with 295mV V_CE(SAT), and integrated low-battery detector with 200mV reference - used in LCD bias, GaAs FET bias, and positive-to-negative conversion.

For engineers reviewing the LT1614CMS8#TRPBF datasheet, LT1614CMS8#TRPBF pinout, LT1614CMS8#TRPBF application, or LT1614CMS8#TRPBF equivalent, key selection criteria include minimum 1V start-up capability, –1.24V feedback reference accuracy, shutdown current <10µA, 8-lead MSOP thermal performance (θ_JA = 120°C/W), and compatibility with ceramic output capacitors for low-noise –5V/200mA conversion.

Technical Context

The LT1614CMS8#TRPBF implements a current-mode PWM architecture with a –1.24V internal reference and 600kHz oscillator, enabling stable regulation of negative outputs without external compensation complexity. Its error amplifier (100V/V gain, 16µmhos transconductance) drives a ramp-comparator-controlled flip-flop to regulate switch duty cycle on a cycle-by-cycle basis.

It supports two topologies: charge-pump–enhanced boost (single inductor) and Cuk-derived inverting (dual inductor), the latter delivering <5mV_P–P ripple with ceramic capacitors. The low-battery detector uses a PNP input stage referenced to 200mV and provides open-collector LBO output with 10µA sink capability.

Key Specifications

Pinout & Package

LT1614CMS8#TRPBF is housed in an 8-lead plastic MSOP (Mini Small Outline Package) with exposed pad thermal enhancement, JEDEC MO-187AC compliant, 3mm × 3mm footprint, 0.65mm pitch, and 120°C/W junction-to-ambient thermal resistance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar inverting switching regulator applications.

Compared with LT1611IS5#TRMPBF and LT1931ES5#TRMPBF, the LT1614CMS8#TRPBF uniquely combines 1V start-up, integrated low-battery detection, and 500mA switch capability in an 8-lead MSOP - making it optimal for battery-powered instrumentation requiring robust bias generation and system health monitoring.

Availability

LT1614CMS8#TRPBF is available at Aetrix Electronics and suitable for MR head bias, LCD panel bias, GaAs FET gate control, and positive-to-negative conversion requiring stable component supply across industrial temperature ranges (–40°C to 85°C).

Supply support for LT1614CMS8#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 legacy of high-performance analog and power management ICs with rigorous automotive and industrial qualification.

The LT1614CMS8#TRPBF belongs to Linear's micropower inverting regulator product line, engineered specifically for portable and battery-critical systems needing clean, efficient negative voltage generation from minimal input headroom.

FAQ

What is the minimum input voltage required for LT1614CMS8#TRPBF to start switching?

The LT1614CMS8#TRPBF has a guaranteed minimum input voltage of 1.0V at 25°C and 1.1V at –40°C. It will initiate switching and regulate output once VIN reaches this threshold, enabling operation from nearly depleted single-cell batteries. Below this level, the internal bandgap reference and oscillator fail to activate, and the device remains non-functional. This specification is validated across the full industrial temperature range.

Can LT1614CMS8#TRPBF operate without the LBI and LBO pins connected?

Yes - the LT1614CMS8#TRPBF functions fully as an inverting regulator with LBI and LBO pins left unconnected (floating). The low-battery detector is disabled by default when SHDN is high, and floating LBI/LBO introduces no functional risk. However, if battery monitoring is required, LBI must be tied to a resistive divider and LBO pulled up to a logic rail; otherwise, these pins may be omitted entirely without affecting regulation performance.

What is the maximum output current achievable with LT1614CMS8#TRPBF in a –5V/200mA application?

The LT1614CMS8#TRPBF supports up to 200mA continuous output at –5V in standard Cuk topology designs, as verified in Figure 1 and TA01 of the datasheet. At higher loads, thermal limits (T_J ≤ 125°C) and switch current limit (~1.2A peak) constrain sustained operation. For 200mA, the MS8 package achieves safe junction temperatures with proper PCB copper area and airflow - exceeding this requires derating or forced cooling.

Does LT1614CMS8#TRPBF require external compensation components?

Yes - the LT1614CMS8#TRPBF requires an external series RC network from VC (Pin 2) to GND for loop stability. Typical values are 100kΩ and 1nF, as shown in all reference schematics. Omitting or mis-sizing this network causes oscillation, poor transient response, or regulation failure. The RC values directly affect phase margin and bandwidth; adjustments are needed only when optimizing for specific load-step requirements or capacitor ESR variations.

Is LT1614CMS8#TRPBF RoHS compliant and lead-free?

Yes - LT1614CMS8#TRPBF is RoHS compliant and lead-free per Analog Devices' product change notification PCN-17-001. The "#TRPBF" suffix explicitly denotes lead-free, halogen-free, and RoHS-compliant packaging (MS8 with matte tin finish). No exemptions apply, and the device meets EU Directive 2011/65/EU and China RoHS II requirements for restricted substances.