Analog Devices Inc. LTC2909CTS8-3.3#TRMPBF

Overview

LTC2909CTS8-3.3#TRMPBF from Analog Devices (formerly Linear Technology) is a precision triple-input voltage supervisor IC designed for system-level power monitoring in space-constrained applications. It features dual adjustable 0.5V-threshold inputs with ±1.5% accuracy over temperature, a fixed 2.921V VCC UVLO threshold, 200ms internal reset timeout, open-drain RST output, and 50μA quiescent current - enabling reliable undervoltage/overvoltage detection for 3.3V logic systems in desktops, servers, and automotive ECUs.

For engineers reviewing the LTC2909CTS8-3.3#TRMPBF datasheet, LTC2909CTS8-3.3#TRMPBF pinout, LTC2909CTS8-3.3#TRMPBF application, or LTC2909CTS8-3.3#TRMPBF equivalent, key selection considerations include input polarity configuration via SEL pin, buffered 1.000V reference for negative supply offset, glitch-filtered comparators, shunt-regulated VCC operation up to 6.5V, and TSOT-23-8 package compatibility with 3mm × 2mm DFN footprints.

Technical Context

The LTC2909CTS8-3.3#TRMPBF implements three independent voltage monitors: two adjustable inputs (ADJ1/ADJ2) with 0.5V nominal thresholds and ±1.5% accuracy across –40°C to 85°C, plus a fixed VCC UVLO set at 2.921V (10% below 3.3V) with identical accuracy. Its three-state SEL pin selects input polarity combinations (positive UV/–OV, negative UV/+OV, or dual negative), enabling flexible fault detection on mixed-polarity rails without external components.

Reset timing is controlled by the TMR pin: grounding enables 200ms internal timeout; capacitive coupling sets external timeout (9ms/nF); tying to VCC disables timeout and activates comparator mode. The buffered 1.000V REF output supports offset-based negative-voltage monitoring, while the 6.5V VCC shunt regulator allows direct connection to supplies up to 6V or higher with series current limiting.

Key Specifications

Pinout & Package

Package: 8-lead TSOT-23 (3mm × 2mm footprint, 0.65mm pitch, exposed pad optional for thermal relief).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervisor applications.

Compared with MAX6326UT33D3+ and TPS3808G33DBVR, the LTC2909CTS8-3.3#TRMPBF uniquely integrates dual adjustable inputs, polarity-selectable monitoring, and a buffered 1V reference - making it the only solution capable of supervising mixed-polarity rails (e.g., +3.3V and –5V) with a single IC in space-constrained embedded systems.

Availability

LTC2909CTS8-3.3#TRMPBF is available at Aetrix Electronics and suitable for desktop computing, automotive body electronics, and network server power management requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for LTC2909CTS8-3.3#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. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors.

The LTC2909 product line delivers precision, low-power voltage supervision for mission-critical power sequencing in computing, communications, and automotive systems - emphasizing accuracy, flexibility, and minimal board footprint.

FAQ

What is the guaranteed operating VCC range for the LTC2909CTS8-3.3#TRMPBF?

The LTC2909CTS8-3.3#TRMPBF operates with VCC as low as 0.5V (guaranteeing RST assertion) and up to 6V directly. Above 6V, its internal 6.5V shunt regulator requires a series current-limiting resistor to keep VCC pin current ≤10mA. Absolute maximum VCC is 6V when connected to a low-impedance source without series resistance.

How does the SEL pin configure input polarity on the LTC2909CTS8-3.3#TRMPBF?

The SEL pin on the LTC2909CTS8-3.3#TRMPBF selects polarity via three states: tied to VCC configures both ADJ1 and ADJ2 for positive UV/(–)OV detection; tied to GND configures both for negative UV/(+)OV; left open configures ADJ1 positive and ADJ2 negative. Leakage current must stay below ±10μA in the open state to ensure correct decoding.

Can the LTC2909CTS8-3.3#TRMPBF monitor a single supply for both undervoltage and overvoltage?

Yes - the LTC2909CTS8-3.3#TRMPBF can monitor one supply for UV and OV using three external resistors and the REF pin. For a positive 3.3V rail, ADJ1 detects UV and ADJ2 detects OV (or vice versa) by configuring SEL appropriately and calculating RP4/RP5/RP6 values per the datasheet's Figure 3 and Table 3.

What is the function of the REF pin on the LTC2909CTS8-3.3#TRMPBF?

The REF pin on the LTC2909CTS8-3.3#TRMPBF provides a buffered 1.000V ±15mV output capable of sourcing/sinking 1mA. It serves as an offset reference for negative-supply monitoring circuits - e.g., connecting ADJ2 to a divider between –5V and REF enables precise –5V UV detection without additional op-amps or references.

Does the LTC2909CTS8-3.3#TRMPBF require an external capacitor on the TMR pin for basic operation?

No - the LTC2909CTS8-3.3#TRMPBF does not require an external capacitor on the TMR pin for basic operation. Tying TMR to GND enables the internal 200ms reset timeout, eliminating the need for external timing components. Capacitors are only required when programmable timeout (9ms/nF) is needed, or when disabling timeout entirely by tying TMR to VCC.