Analog Devices Inc. LTC2909CDDB-3.3#TRMPBF

Overview

LTC2909CDDB-3.3#TRMPBF from Analog Devices (formerly Linear Technology) is a precision dual adjustable-input undervoltage/overvoltage monitor with fixed 3.3V VCC UVLO, ±1.5% threshold accuracy, 50μA quiescent current, and 200ms internal reset timeout - used for reliable power sequencing and fault detection in 3.3V logic systems such as network servers and embedded computing.

For engineers reviewing the LTC2909CDDB-3.3#TRMPBF datasheet, LTC2909CDDB-3.3#TRMPBF pinout, LTC2909CDDB-3.3#TRMPBF application, or LTC2909CDDB-3.3#TRMPBF equivalent, key selection criteria include input polarity configurability via SEL pin, buffered 1V reference for negative supply offset, guaranteed 0.5V ADJ threshold accuracy over temperature, ultralow 0.5V VCC operation, and open-drain RST output with glitch rejection.

Technical Context

The LTC2909CDDB-3.3#TRMPBF implements two independent 0.5V-threshold comparators with polarity selectable via three-state SEL pin (VCC/Open/GND), enabling simultaneous monitoring of positive UV/OV, negative UV/OV, or mixed-polarity supplies. 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 timing is configurable: internal 200ms timeout (TMR = GND), external capacitor-based (9ms/nF), or comparator mode (TMR = VCC). The buffered 1V reference (±15mV accuracy, ±1mA drive) supports offset-based negative voltage monitoring without external components, while input glitch filtering prevents false triggering from transients.

Key Specifications

Pinout & Package

Package: 8-lead 3mm × 2mm DFN (DDB), exposed pad (Pin 9) optional ground connection for thermal management.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6316US33D3+ and TPS3808G33DBVR, the LTC2909CDDB-3.3#TRMPBF uniquely supports dual adjustable inputs with polarity selection and integrated 1V reference - enabling compact, flexible monitoring of mixed-polarity or dual-rail systems without external components.

Availability

LTC2909CDDB-3.3#TRMPBF is available at Aetrix Electronics and suitable for network servers, industrial PLCs, and automotive infotainment systems requiring stable component supply, long-term lifecycle support, and guaranteed parametric performance.

Supply support for LTC2909CDDB-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 designs high-performance analog, mixed-signal, and digital signal processing semiconductors for precision measurement, power management, and signal conditioning applications.

The LTC2909 product line delivers highly accurate, low-power supply supervisors with configurable monitoring architectures - engineered for reliability-critical systems including computing infrastructure, industrial automation, and automotive electronics.

FAQ

What is the guaranteed VCC UVLO threshold for LTC2909CDDB-3.3#TRMPBF?

The LTC2909CDDB-3.3#TRMPBF has a guaranteed VCC undervoltage lockout threshold of 2.921V (–10% of 3.3V) with ±1.5% accuracy over the full operating temperature range (–40°C to 85°C). This specification ensures deterministic reset assertion when the 3.3V supply drops below 2.871V minimum, supporting robust power-up sequencing in noise-prone environments.

How does the SEL pin configure input polarity on LTC2909CDDB-3.3#TRMPBF?

The SEL pin on LTC2909CDDB-3.3#TRMPBF selects one of three polarity combinations: tied to VCC configures both ADJ1 and ADJ2 for positive UV/OV monitoring; left open configures ADJ1 for positive and ADJ2 for negative monitoring; tied to GND configures both for negative UV/OV. Each configuration requires no external components and maintains ±1.5% threshold accuracy.

Can LTC2909CDDB-3.3#TRMPBF monitor negative voltages, and how is it implemented?

Yes, LTC2909CDDB-3.3#TRMPBF can monitor negative voltages using its buffered 1V reference (REF pin) as an offset. When SEL is configured for negative polarity, ADJ1 or ADJ2 is connected between the negative supply and REF - e.g., to detect –4.425V UV on a –5V rail. The 0.5V comparator threshold becomes effective relative to REF, enabling accurate negative supply supervision without external op-amps.

What is the minimum VCC voltage that ensures valid RST output from LTC2909CDDB-3.3#TRMPBF?

The LTC2909CDDB-3.3#TRMPBF guarantees RST output functionality down to VCC = 0.5V. At this voltage, the open-drain RST pin can sink sufficient current to maintain a logic-low state (<0.15V at 100μA load), ensuring fail-safe reset assertion during deep brownout conditions where other supervisors may lose regulation.

Does LTC2909CDDB-3.3#TRMPBF require an external timing capacitor for standard operation?

No, LTC2909CDDB-3.3#TRMPBF does not require an external timing capacitor for standard operation. When the TMR pin is tied to GND, the device uses its internal 200ms reset timeout - eliminating external components while maintaining precise, temperature-stable delay. External capacitors are only needed for non-standard timeout durations (e.g., 10ms or 2s) or comparator-mode bypass.