Analog Devices Inc. LTC2911IDDB-1#TRPBF

Overview

LTC2911IDDB-1#TRPBF from Analog Devices (formerly Linear Technology) is a precision triple supply monitor IC with integrated power-fail comparator and reset latching capability. It monitors 3.3V (V1), 5V (V2), and an adjustable input (ADJ) with ±1.5% threshold accuracy over –40°C to 85°C, supports internal 200ms reset timeout, and operates down to 0.5V VCC for reliable power-up sequencing in embedded power management systems.

For engineers reviewing the LTC2911IDDB-1#TRPBF datasheet, LTC2911IDDB-1#TRPBF pinout, LTC2911IDDB-1#TRPBF application, or LTC2911IDDB-1#TRPBF equivalent, key selection criteria include its fixed 3.3V/5V dual-supply monitoring configuration, DFN-8 (3mm × 2mm) package with exposed pad, guaranteed ultralow-voltage operation at VCC = 0.5V, and PFI/PFO early-warning power-fail signaling with 500mV falling threshold.

Technical Context

The LTC2911IDDB-1#TRPBF implements three independent voltage comparators: one fixed 3.3V (–6.5% = 3.086V) monitor on V1, one fixed 5V (–6.5% = 4.675V) monitor on V2, and one adjustable 0.5V-threshold comparator on ADJ-enabling resistive-divider configuration of a third supply. Its internal VCC is derived from the higher of V1 or V2, supporting autonomous operation without external bias.

It integrates a dedicated power-fail comparator (PFI → PFO) with 500mV falling / 515mV rising thresholds (3% hysteresis), a TMR-controlled latch mode for margin testing, and glitch-immune timing with 8–80µs propagation delay. Reset assertion requires all three monitored inputs to remain below threshold for ≥8µs, and release requires validity for ≥200ms (internal timeout) or configurable external timeout via CTMR.

Key Specifications

Pinout & Package

Package: 8-lead (3mm × 2mm) plastic DFN with exposed pad (pin 9, GND). Compact footprint supports high-density PCB layouts in space-constrained industrial and computing applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6361KA29+T and TPS3808G33DBVR, the LTC2911IDDB-1#TRPBF delivers integrated triple-rail supervision with power-fail warning and latch mode in a single DFN-8 package - reducing component count, layout complexity, and validation effort for systems requiring coordinated multi-supply health monitoring.

Availability

LTC2911IDDB-1#TRPBF is available at Aetrix Electronics and suitable for server power sequencing, industrial PLC I/O modules, automotive infotainment head units, and medical diagnostic imaging subsystems requiring stable component supply and long-term lifecycle support.

Supply support for LTC2911IDDB-1#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, Inc. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LTC2911 family was designed by Linear Technology (acquired by ADI in 2017) specifically for precision multi-rail power monitoring in mission-critical embedded systems where reliability, accuracy, and ultralow-voltage operation are essential.

FAQ

What is the exact reset threshold voltage for the V1 pin on the LTC2911IDDB-1#TRPBF?

The V1 pin on the LTC2911IDDB-1#TRPBF has a nominal reset threshold of 3.086V (3.3V –6.5%), with guaranteed accuracy of ±1.5% over the full –40°C to 85°C operating temperature range. This means the actual threshold lies between 3.036V and 3.135V under all specified conditions, ensuring robust detection without false triggering near supply tolerance edges.

Does the LTC2911IDDB-1#TRPBF support power-fail detection on a 12V supply?

Yes - the LTC2911IDDB-1#TRPBF supports power-fail detection on a 12V supply via the PFI pin using an external resistive divider. The PFI input has a fixed 500mV falling threshold, so a 24:1 resistor ratio (e.g., 240kΩ top, 10kΩ bottom) scales 12V down to 0.5V. Hysteresis is inherent (515mV rising), and the divider must use ≤100kΩ for R3 to minimize bias current error.

Can the LTC2911IDDB-1#TRPBF monitor a 1.8V supply as its third input?

No - the LTC2911IDDB-1#TRPBF is the -1 variant, configured specifically for 3.3V (V1) and 5V (V2) monitoring. Its ADJ pin is adjustable (0.5V threshold) and can monitor a 1.8V rail via a 3.6:1 resistive divider (1.8V ÷ 3.6 = 0.5V), but the V2 pin itself is fixed at 5V and cannot be reconfigured for 1.8V. For factory-set 1.8V on V2, use LTC2911IDDB-3#TRPBF instead.

How does the TMR pin function in latch mode on the LTC2911IDDB-1#TRPBF?

When the TMR pin on the LTC2911IDDB-1#TRPBF is pulled to GND, the RST output latches its current state (high or low) and ignores subsequent changes on V1/V2/ADP until TMR is released. This enables margin testing at reduced voltages without spurious resets. Release timing depends on input validity: if all rails are valid at release, RST transitions immediately; if invalid, it asserts after t_P,LR (≤3µs) or times out normally.

Is the exposed pad on the LTC2911IDDB-1#TRPBF's DFN package electrically connected?

Yes - the exposed pad (pin 9) on the LTC2911IDDB-1#TRPBF's 8-lead DFN package is internally connected to GND. It must be soldered to a PCB ground plane for optimal thermal performance (θ_JA = 76°C/W) and electrical stability. Leaving it unconnected degrades thermal dissipation and may cause erratic comparator behavior due to floating substrate potential.