Analog Devices Inc. LTC2911CDDB-5#TRPBF

Overview

LTC2911CDDB-5#TRPBF from Analog Devices (formerly Linear Technology) is a precision triple supply monitor IC with integrated power-fail comparator and latched reset control. It monitors 3.3V (V1), an adjustable supply (V2), and a second adjustable input (ADJ), all with ±1.5% threshold accuracy over 0°C to 70°C. Features include 200ms internal reset timeout, 0.5V PFI threshold with 15mV hysteresis, and ultralow 30µA quiescent current - deployed in industrial power sequencing and embedded system margin testing.

For engineers reviewing the LTC2911CDDB-5#TRPBF datasheet, LTC2911CDDB-5#TRPBF pinout, LTC2911CDDB-5#TRPBF application, or LTC2911CDDB-5#TRPBF equivalent, key selection considerations include its V2/ADJ dual-adjustable architecture, DFN-8 (3mm × 2mm) package with exposed pad, latch-enabled RST control via TMR, and guaranteed operation down to VCC = 0.5V for robust power-up supervision.

Technical Context

The LTC2911CDDB-5#TRPBF implements three independent voltage comparators: one fixed 3.3V monitor (V1), one high-impedance adjustable monitor (V2) with 500mV nominal threshold, and a second adjustable monitor (ADJ) also at 500mV. All comparators feature 1.5% accuracy across temperature and built-in glitch filtering for noise immunity.

Its power-fail function uses the PFI input (500mV falling / 515mV rising threshold) to drive PFO low for early warning of supply collapse. The TMR pin supports three modes: external capacitor timeout (9.4ms/nF), internal 200ms timeout (TMR = V1), or latch mode (TMR = GND) to hold RST state during margin testing.

Key Specifications

Pinout & Package

Package: 8-lead (3mm × 2mm) plastic DFN with exposed pad (Pin 9), RoHS-compliant, θJA = 76°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar triple-supply monitoring applications.

Compared with MAX6369KA+T and TPS3808G33DBVR, the LTC2911CDDB-5#TRPBF uniquely delivers dual adjustable inputs (V2 + ADJ), ±1.5% accuracy, and integrated PFI/PFO - enabling compact, high-precision triple-rail supervision without external components or accuracy compromises.

Availability

LTC2911CDDB-5#TRPBF is available at Aetrix Electronics and suitable for industrial power sequencing, embedded system margin testing, network equipment supervision, and battery-powered edge node monitoring requiring stable component supply and long-term lifecycle support.

Supply support for LTC2911CDDB-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 its high-precision analog IC portfolio, emphasizing performance, reliability, and automotive/industrial qualification.

The LTC2911 family is designed for mission-critical power supervision in systems demanding ±1.5% threshold accuracy, latch-enabled margin testing, and seamless integration of reset + power-fail signaling in space-constrained DFN packages.

FAQ

What is the exact reset threshold voltage for the V1 pin on the LTC2911CDDB-5#TRPBF?

The V1 pin of the LTC2911CDDB-5#TRPBF has a guaranteed reset threshold of 3.086V ±1.5% over 0°C to 70°C, corresponding to a 3.3V supply with –6.5% tolerance. This means the actual trip point falls between 3.036V and 3.135V across temperature, preventing false resets during normal ±5% supply variation. The LTC2911CDDB-5#TRPBF uses this fixed threshold exclusively for the 3.3V rail, independent of V2 or ADJ configuration.

How does the LTC2911CDDB-5#TRPBF differ from other LTC2911 variants like LTC2911-1 or LTC2911-2?

The LTC2911CDDB-5#TRPBF is the LTC2911-5 variant, meaning its V2 pin functions identically to the ADJ pin - both are high-impedance 500mV-threshold inputs for adjustable monitoring. In contrast, LTC2911-1 monitors 5V on V2, LTC2911-2 monitors 2.5V, etc. Only LTC2911-5 supports dual adjustable inputs, making the LTC2911CDDB-5#TRPBF uniquely suited for systems requiring two custom trip points without external references.

Can the LTC2911CDDB-5#TRPBF operate with supply voltages below 1V, and what happens to RST/PFO outputs?

Yes, the LTC2911CDDB-5#TRPBF guarantees functional RST and PFO outputs down to VCC = 0.5V, enabled by proprietary low-voltage drive circuitry. When V1 drops below 1V but remains ≥0.5V, RST and PFO maintain valid logic-low states during brownout, preventing indeterminate microcontroller behavior. Below 0.5V, operation is not specified. This capability is intrinsic to the LTC2911CDDB-5#TRPBF design and does not require external level-shifting.

What is the purpose of the exposed pad (Pin 9) on the LTC2911CDDB-5#TRPBF DFN package?

The exposed pad (Pin 9) on the LTC2911CDDB-5#TRPBF is electrically and thermally connected to GND. It must be soldered to a PCB ground plane to achieve the specified θJA = 76°C/W thermal resistance and ensure stable operation under sustained load. Leaving it unconnected degrades thermal performance and may cause premature thermal shutdown or parameter drift. The LTC2911CDDB-5#TRPBF datasheet explicitly states PCB connection is optional only for mechanical retention - electrical grounding is mandatory for specification compliance.

How do I configure the power-fail warning (PFO) threshold using the PFI pin on the LTC2911CDDB-5#TRPBF?

To configure the PFO threshold, connect a resistive divider from the supply to GND, with the midpoint feeding the PFI pin. Since the LTC2911CDDB-5#TRPBF's PFI has a 500mV falling threshold and 515mV rising threshold, select R3 and R4 such that V_PFI = 0.5V at the desired supply trip point. For example, to trigger PFO at 4.5V on a 5V rail: R3 = 100kΩ, R4 = 900kΩ. The LTC2911CDDB-5#TRPBF's 3% hysteresis inherently rejects noise without requiring external capacitors unless extreme EMI is present.