Analog Devices Inc. LTC2909CDDB-5#TRPBF

Overview

LTC2909CDDB-5#TRPBF from Analog Devices (formerly Linear Technology) is a precision triple-input voltage supervisor IC designed for system-level power monitoring in embedded and industrial electronics. It features dual adjustable 0.5V-threshold inputs with ±1.5% accuracy over temperature, a fixed 4.425V VCC UVLO threshold, 200ms internal reset timeout, and open-drain RST output - enabling robust undervoltage/overvoltage detection for 5V logic rails, core supplies, and negative-bias rails in desktop, server, and automotive applications.

For engineers reviewing the LTC2909CDDB-5#TRPBF datasheet, LTC2909CDDB-5#TRPBF pinout, LTC2909CDDB-5#TRPBF application, or LTC2909CDDB-5#TRPBF equivalent, key selection considerations include its 8-lead DFN (3mm × 2mm) package, SEL-pin polarity configuration, buffered 1V reference for negative-supply offset, 50μA quiescent current, and guaranteed 0.5V reset assertion down to VCC = 0.5V.

Technical Context

The LTC2909CDDB-5#TRPBF implements three independent voltage comparators: two with user-adjustable thresholds (nominal 0.5V, ±1.5% accuracy) and one fixed VCC UVLO (4.425V, ±1.5%). Polarity of ADJ1/ADJ2 is selected via the three-state SEL pin (VCC/Open/GND), enabling simultaneous positive-UV/negative-OV or dual-negative monitoring without external components.

Its reset logic combines glitch filtering (rejecting transients <500ns at 5% overthreshold) and programmable timeout (internal 200ms, external capacitor, or comparator mode). The buffered 1.000V REF output (±15mV accuracy, ±1mA drive) supports offset-based negative-rail sensing, while the 6.5V shunt regulator on VCC allows direct operation up to 6V or high-voltage supply interfacing with series current-limiting resistor.

Key Specifications

Pinout & Package

8-lead DFN (3mm × 2mm) package with exposed thermal pad (Pin 9, optional GND connection). Pinout optimized for minimal external component count in dual-supply monitoring.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326US33D3+T and TPS3808G33DBVR, the LTC2909CDDB-5#TRPBF provides unique dual adjustable inputs, polarity selection, and buffered reference - making it irreplaceable for multi-rail or negative-supply monitoring, whereas alternatives serve only basic single-rail reset generation.

Availability

LTC2909CDDB-5#TRPBF is available at Aetrix Electronics and suitable for desktop computing, automotive infotainment, and network server applications requiring stable component supply, long-lifecycle availability, and guaranteed parametric performance across temperature.

Supply support for LTC2909CDDB-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, multi-rail voltage supervision for mission-critical systems where supply integrity directly impacts functional safety and data reliability.

FAQ

What is the function of the SEL pin on the LTC2909CDDB-5#TRPBF?

The SEL pin on the LTC2909CDDB-5#TRPBF is a three-state input that configures the polarity of ADJ1 and ADJ2 inputs without external components. When tied to VCC, both inputs operate in positive-UV mode; when grounded, both operate in negative-OV mode; when left open, they operate in mixed polarity. This enables flexible monitoring of positive, negative, or dual-polarity supplies using the same LTC2909CDDB-5#TRPBF device.

Does the LTC2909CDDB-5#TRPBF support monitoring of negative voltage rails?

Yes, the LTC2909CDDB-5#TRPBF supports negative rail monitoring via its buffered 1.000V REF output and polarity-selectable ADJ inputs. When SEL = GND, ADJ1 and ADJ2 interpret voltages relative to REF, allowing detection of undervoltage on –5V or –12V supplies. External resistor dividers referenced to REF set the exact trip point, and the LTC2909CDDB-5#TRPBF maintains ±1.5% threshold accuracy across temperature.

What is the minimum VCC voltage required for the LTC2909CDDB-5#TRPBF to assert a valid reset?

The LTC2909CDDB-5#TRPBF guarantees RST assertion down to VCC = 0.5V, with VOL ≤ 0.15V at I_RST = 2500μA. This ultralow-voltage operation ensures reliable reset signaling during deep brownout events where other supervisors fail, making the LTC2909CDDB-5#TRPBF suitable for safety-critical systems requiring fail-safe behavior across wide input voltage ranges.

Can the reset timeout of the LTC2909CDDB-5#TRPBF be disabled?

Yes, the reset timeout of the LTC2909CDDB-5#TRPBF can be disabled by connecting the TMR pin to VCC, placing the device in comparator mode. In this mode, comparator outputs drive RST directly without timeout delay, enabling application-specific reset logic. Note that comparator mode adds ~0.7% one-sided hysteresis to improve noise immunity, and glitch filtering remains active.

What is the purpose of the REF pin on the LTC2909CDDB-5#TRPBF?

The REF pin on the LTC2909CDDB-5#TRPBF provides a buffered 1.000V ±15mV reference output capable of sourcing/sinking ±1mA. It serves as a stable offset for negative-supply monitoring circuits - for example, connecting ADJ1 to a resistor divider between –5V and REF enables precise –5V undervoltage detection. The REF output eliminates the need for an external precision reference in such configurations.