Analog Devices Inc. LTC2909CDDB-2.5#TRPBF

Overview

LTC2909CDDB-2.5#TRPBF from Analog Devices (acquired Linear Technology) is a precision dual adjustable-input undervoltage/overvoltage monitor with fixed 2.5V VCC UVLO, ±1.5% threshold accuracy, 50μA quiescent current, and 8-lead DFN package. It monitors two external supplies (e.g., core and I/O rails) for fault conditions while supporting negative-voltage monitoring via buffered 1.000V reference and pin-selectable input polarity.

For engineers reviewing the LTC2909CDDB-2.5#TRPBF datasheet, LTC2909CDDB-2.5#TRPBF pinout, LTC2909CDDB-2.5#TRPBF application, or LTC2909CDDB-2.5#TRPBF equivalent, key selection considerations include guaranteed 0.5V ADJ threshold accuracy over –40°C to 85°C, internal 200ms reset timeout, open-drain RST output with 0.5V VCC operation, and SEL pin polarity configuration for mixed positive/negative supply monitoring in space-constrained systems.

Technical Context

The LTC2909CDDB-2.5#TRPBF implements dual 0.5V-comparator inputs with programmable polarity (positive UV/–OV or negative UV/+OV) selected via three-state SEL pin, enabling detection of four distinct fault combinations across two supplies. Its third fixed-threshold UVLO on VCC is calibrated to 2.213V (±1.5%) for 2.5V logic systems.

Reset assertion uses glitch-filtered comparator outputs feeding a timeout circuit configurable as internal 200ms, external capacitor-timed (9ms/nF), or disabled (comparator mode). The buffered 1.000V REF output (±15mV over temperature, ±1mA drive) provides offset for negative-rail monitoring without external components.

Key Specifications

Pinout & Package

Package: 8-lead 3mm × 2mm plastic DFN (DDB) with exposed pad (pin 9), rated for 0°C to 70°C operation (C-grade).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC2909CDDB-2.5#TRPBF, TPS3808G125DBVR offers lower cost but sacrifices dual-rail flexibility and negative monitoring, while MAX6816EUT+T provides fixed thresholds for common logic rails but lacks the precision adjustable inputs and buffered reference needed for custom or mixed-polarity applications.

Availability

LTC2909CDDB-2.5#TRPBF is available at Aetrix Electronics and suitable for desktop computers, notebook power management, automotive infotainment systems, and network server power sequencing requiring stable component supply and long-term lifecycle support.

Supply support for LTC2909CDDB-2.5#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 LTC2909 product line delivers precision, low-power supply monitoring solutions for computing and embedded systems where accurate voltage supervision and compact packaging are critical design requirements.

FAQ

What is the guaranteed operating temperature range for the LTC2909CDDB-2.5#TRPBF?

The LTC2909CDDB-2.5#TRPBF is specified for commercial temperature operation from 0°C to 70°C. This C-grade rating ensures consistent performance in desktop, notebook, and industrial computing environments where ambient temperatures remain within this range. The device maintains ±1.5% threshold accuracy across this full span, critical for reliable power-on reset behavior without derating.

How does the SEL pin configure input polarity on the LTC2909CDDB-2.5#TRPBF?

The SEL pin on the LTC2909CDDB-2.5#TRPBF determines ADJ1 and ADJ2 polarity through three states: connected to VCC sets both inputs for positive polarity (UV detection), grounded sets both for negative polarity (UV detection), and left open configures ADJ1 positive and ADJ2 negative. This eliminates external logic components, enabling flexible monitoring of mixed positive/negative rails like +5V and –12V in a single IC.

Can the LTC2909CDDB-2.5#TRPBF monitor a single supply for both undervoltage and overvoltage conditions?

Yes, the LTC2909CDDB-2.5#TRPBF can monitor one supply for UV and OV using three external resistors and the REF output. For a positive supply, connect ADJ1 to a divider tap for UV detection and ADJ2 to another tap for OV detection, with SEL = VCC. For negative supplies, use REF as the upper rail in the divider. This configuration avoids needing separate UV/OV supervisors.

What is the minimum VCC voltage required for the LTC2909CDDB-2.5#TRPBF to assert a valid reset output?

The LTC2909CDDB-2.5#TRPBF guarantees RST output low voltage (VOL) of ≤0.15V at VCC = 0.5V with 100μA sink current. This ultralow-voltage operation ensures reliable reset assertion during severe brownout conditions, allowing system shutdown before critical logic fails-unlike many supervisors requiring ≥1.0V VCC to function.

Does the LTC2909CDDB-2.5#TRPBF require external components for basic operation?

The LTC2909CDDB-2.5#TRPBF requires minimal external components: a 0.1μF bypass capacitor on VCC, an external pull-up resistor on RST, and resistor dividers on ADJ1/ADJ2 to set trip points. No additional capacitors, references, or level-shifters are needed-the integrated 1.000V REF and SEL-configurable polarity eliminate typical external complexity for negative-rail monitoring.