Analog Devices Inc. LTC2911HTS8-2#TRMPBF

Overview

LTC2911HTS8-2#TRMPBF from Analog Devices (formerly Linear Technology) is a high-accuracy triple supply monitor IC with integrated power-fail comparator and latched reset control. It monitors 3.3V (V1), 2.5V (V2), and an adjustable input (ADJ) with ±1.5% threshold accuracy over –40°C to +125°C, supports internal 200ms reset timeout, and delivers ultralow 30µA quiescent current - deployed in automotive engine control units for multi-rail voltage supervision during cold-crank conditions.

For engineers reviewing the LTC2911HTS8-2#TRMPBF datasheet, LTC2911HTS8-2#TRMPBF pinout, LTC2911HTS8-2#TRMPBF application, or LTC2911HTS8-2#TRMPBF equivalent, key selection criteria include guaranteed 0.5V operation, PFI hysteresis of 15mV typical, TMR latch functionality for margin testing, and TSOT-23-8 package compatibility with space-constrained automotive PCB layouts.

Technical Context

The LTC2911HTS8-2#TRMPBF implements three independent voltage comparators: V1 fixed at 3.086V (–6.5% of 3.3V), V2 fixed at 2.338V (–6.5% of 2.5V), and ADJ with 500mV nominal threshold. Its internal VCC is derived from the higher of V1 or V2, enabling operation down to 0.5V supply while maintaining RST/PFO logic integrity.

It features dual-mode timing control: TMR pin selects between internal 200ms timeout (TMR = V1) or external capacitor-based timeout (e.g., 20ms with 2.2nF), plus latch mode (TMR = GND) to hold RST state during voltage margining - all with glitch-immune propagation delays under 80µs for V1/V2/ADJ undervoltage detection.

Key Specifications

Pinout & Package

Package: 8-lead TSOT-23 (TS8), 3mm × 1.75mm footprint, exposed pad optional, θ_JA = 195°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6369AUT+T and TPS3808G33DBVR, the LTC2911HTS8-2#TRMPBF uniquely integrates triple-rail monitoring, PFI early-warning, and TMR latch in one TSOT-23-8 package - delivering 72% smaller footprint and eliminating 5 external components required by alternative solutions.

Availability

LTC2911HTS8-2#TRMPBF is available at Aetrix Electronics and suitable for automotive engine control, ADAS camera modules, infotainment SoC sequencing, and EV battery management interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LTC2911HTS8-2#TRMPBF 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. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving automotive, industrial, communications, and healthcare markets.

The LTC2911 family was designed specifically for automotive-grade multi-rail power supervision - emphasizing ±1.5% threshold accuracy over –40°C to +125°C, ultralow-voltage operation, and integrated power-fail warning to meet stringent ISO 26262 functional safety readiness requirements.

FAQ

What is the guaranteed minimum operating voltage for LTC2911HTS8-2#TRMPBF to assert RST and PFO correctly?

The LTC2911HTS8-2#TRMPBF guarantees correct RST and PFO assertion down to VCC = 0.5V, enabled by proprietary low-voltage drive circuitry. This ensures deterministic reset behavior during severe brownout events such as automotive cold-cranking, where battery voltage may dip below 6V. The specification is verified across the full –40°C to +125°C temperature range and applies to both outputs regardless of whether V1 or V2 supplies VCC.

How does the TMR pin function in latch mode for margin testing with LTC2911HTS8-2#TRMPBF?

When the TMR pin of the LTC2911HTS8-2#TRMPBF is pulled to GND, the RST output state is latched - holding its current logic level regardless of subsequent V1/V2/ADJ voltage changes. This enables controlled voltage margining: for example, forcing RST low during 3.3V rail reduction to verify system response without triggering unintended resets. Release occurs when TMR rises above VTMR(LATCH) ≈ 0.20V, after which RST transitions based on real-time input validity and timeout.

Can LTC2911HTS8-2#TRMPBF monitor a 1.2V supply, and if so, how is it configured?

The LTC2911HTS8-2#TRMPBF does not natively support 1.2V monitoring on V2 (it is fixed to 2.5V for this variant), but the ADJ pin can be used with a resistive divider to configure a 1.2V trip point. For example, connecting a 1.2V rail to ADJ via R1 = 100kΩ and R2 = 140kΩ yields V_ADJ = 1.2V × 100k/(100k + 140k) ≈ 0.5V - matching the ADJ threshold. Resistor tolerance ≤0.1% is recommended to maintain ±1.5% overall accuracy.

What is the hysteresis value of the PFI comparator in LTC2911HTS8-2#TRMPBF, and why is it important?

The PFI comparator in the LTC2911HTS8-2#TRMPBF has 15mV typical hysteresis (500mV falling / 515mV rising), providing 3% noise immunity around the power-fail threshold. This prevents oscillation during noisy supply transitions - critical in automotive environments with alternator ripple or load-dump transients. The hysteresis is factory-trimmed and guaranteed over temperature, eliminating need for external Schmitt-trigger circuits.

Does LTC2911HTS8-2#TRMPBF require external pull-up resistors on RST and PFO pins?

The LTC2911HTS8-2#TRMPBF provides internal weak pull-ups to V1 (≈29µA at V1 = 3.3V), sufficient for high-impedance CMOS inputs. However, external pull-ups are required when driving heavy capacitive loads (>50pF), interfacing with higher-voltage logic (e.g., 5V systems), or needing faster rise times (<1µs). For 3.3V systems with moderate fanout, the internal pull-up is adequate - confirmed by VOH ≥ V1 – 1V at –1µA sink current.