Analog Devices Inc. LTC2909ITS8-3.3#TRMPBF

Overview

LTC2909ITS8-3.3#TRMPBF from Analog Devices (acquired Linear Technology) is a precision dual-input UV/OV monitor with fixed 3.3V VCC UVLO, ±1.5% threshold accuracy, 50μA quiescent current, and 200ms internal reset timeout - used for core voltage supervision in industrial embedded systems and network servers.

For engineers reviewing the LTC2909ITS8-3.3#TRMPBF datasheet, LTC2909ITS8-3.3#TRMPBF pinout, LTC2909ITS8-3.3#TRMPBF application, or LTC2909ITS8-3.3#TRMPBF equivalent, key selection factors include input polarity configurability via SEL pin, buffered 1V reference for negative supply offset, glitch-filtered comparators, and TSOT-23 package compatibility with space-constrained PCB layouts.

Technical Context

The LTC2909ITS8-3.3#TRMPBF implements two adjustable 0.5V-threshold comparators with polarity selection via three-state SEL pin (VCC/GND/open), enabling flexible monitoring of positive UV/OV or negative UV/OV conditions. Its third fixed UVLO channel monitors VCC at 2.921V (–10% of 3.3V) with ±1.5% accuracy across –40°C to +85°C.

Reset assertion uses open-drain ⎯R⎯S⎯T output with programmable timeout: internal 200ms (TMR = GND), external capacitor (9ms/nF), or comparator mode (TMR = VCC). Input glitch rejection is achieved via analog low-pass filtering prior to comparator latching, not hysteresis - preserving threshold accuracy while suppressing transients under 100μs.

Key Specifications

Pinout & Package

8-lead TSOT-23 plastic package (3mm × 1.75mm footprint, 0.65mm pitch), thermally enhanced with exposed pad (not electrically connected in TSOT-23 variant).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-input voltage monitor applications.

Compared with LTC2909CTS8-3.3#TRMPBF and MAX6816EUT+T, the LTC2909ITS8-3.3#TRMPBF uniquely delivers industrial-temperature dual-input supervision with polarity flexibility and buffered reference - enabling compact, high-accuracy monitoring of asymmetric or bipolar supply architectures without design compromises.

Availability

LTC2909ITS8-3.3#TRMPBF is available at Aetrix Electronics and suitable for industrial embedded systems, network server power management, and automotive infotainment designs requiring stable component supply and long-term lifecycle support.

Supply support for LTC2909ITS8-3.3#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. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LTC2909ITS8-3.3#TRMPBF belongs to ADI's precision power monitoring product line, engineered for high-accuracy, low-power, multi-rail voltage supervision in mission-critical embedded systems where reliability and thermal robustness are essential.

FAQ

What is the guaranteed minimum VCC voltage for LTC2909ITS8-3.3#TRMPBF to assert a valid reset output?

The LTC2909ITS8-3.3#TRMPBF guarantees RST output low voltage ≤0.15V when VCC ≥0.5V, enabling reliable reset signaling during deep brownout conditions. This ultralow operating voltage ensures the LTC2909ITS8-3.3#TRMPBF remains functional even as system supplies collapse, making it suitable for fail-safe power sequencing in safety-critical applications.

How does the SEL pin configure input polarity on LTC2909ITS8-3.3#TRMPBF, and what are the valid connection states?

The SEL pin on LTC2909ITS8-3.3#TRMPBF accepts three valid states: tied to VCC (both ADJ1 and ADJ2 monitor positive supplies for UV/OV), tied to GND (both monitor negative supplies for UV/OV), or left open (ADJ1 positive, ADJ2 negative polarity). Each state is validated by internal decode logic; leakage current is limited to ±10μA in open state, ensuring robust operation without external pull resistors.

Can LTC2909ITS8-3.3#TRMPBF monitor a single supply for both undervoltage and overvoltage conditions?

Yes, the LTC2909ITS8-3.3#TRMPBF can monitor one supply for UV and OV using a three-resistor network connecting ADJ1 and ADJ2 to the same monitored rail and REF. For example, a +15V supply can be configured with RP4/RP5/RP6 to trigger ADJ1 on UV (14.25V) and ADJ2 on OV (15.75V) simultaneously - achieving window monitoring with a single IC and no additional comparators.

What is the accuracy of the VCC UVLO threshold for LTC2909ITS8-3.3#TRMPBF, and how is it calibrated?

The VCC UVLO threshold for LTC2909ITS8-3.3#TRMPBF is 2.921V (–10% of 3.3V) with ±1.5% accuracy over –40°C to +85°C. This value is factory-trimmed and specified in the Electrical Characteristics table; no user calibration is required. The tolerance accounts for process variation, temperature drift, and supply regulation effects - ensuring consistent reset behavior across environmental extremes.

Does LTC2909ITS8-3.3#TRMPBF require an external bypass capacitor on the VCC pin?

Yes, LTC2909ITS8-3.3#TRMPBF requires a ≥0.1μF ceramic bypass capacitor from VCC to GND, placed as close as possible to the pin. This stabilizes the internal shunt regulator and suppresses high-frequency noise that could affect comparator accuracy. Omitting the capacitor may cause erratic reset behavior or increased susceptibility to supply ripple, especially when operating near the 6V shunt regulation limit.