Analog Devices Inc. LTC2909IDDB-3.3#TRMPBF

Overview

LTC2909IDDB-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 two adjustable 0.5V-threshold inputs with ±1.5% accuracy, a fixed 2.921V VCC UVLO threshold, 200ms internal reset timeout, and open-drain RST output - enabling reliable undervoltage/overvoltage detection for 3.3V logic systems in desktop computers, network servers, and automotive ECUs.

For engineers reviewing the LTC2909IDDB-3.3#TRMPBF datasheet, LTC2909IDDB-3.3#TRMPBF pinout, LTC2909IDDB-3.3#TRMPBF application, or LTC2909IDDB-3.3#TRMPBF equivalent, this page delivers verified specifications, polarity-selectable dual-input monitoring architecture, DFN-8 package layout, real-world fault-detection use cases, and validated alternative parts for supply supervision design-in.

Technical Context

The LTC2909IDDB-3.3#TRMPBF implements a dual-comparator architecture with a three-state SEL pin that configures ADJ1/ADJ2 input polarity (positive UV/negative OV, mixed, or negative UV/positive OV). Its buffered 1.000V reference enables accurate offset-based negative-supply monitoring without external components.

Reset assertion is synchronized across all monitored rails: VCC must exceed 2.921V (±1.5%), and both ADJ inputs must satisfy their configured polarity condition before the 200ms internal timeout begins. Glitch rejection filtering and propagation delay of 50–500μs prevent false triggering during transient events.

Key Specifications

Pinout & Package

Package: 8-lead plastic DFN (3mm × 2mm), 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 voltage supervisor applications.

Compared with TPS3808G33DBVR and MAX6369KA33+T, the LTC2909IDDB-3.3#TRMPBF uniquely supports dual adjustable inputs with polarity selection and a buffered 1V reference - making it the only option among the three capable of monitoring both positive and negative supplies in a single 3mm × 2mm DFN package.

Availability

LTC2909IDDB-3.3#TRMPBF is available at Aetrix Electronics and suitable for desktop computing, automotive body electronics, and industrial PLC applications requiring stable component supply, long-term lifecycle support, and guaranteed parametric performance across –40°C to +85°C.

Supply support for LTC2909IDDB-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 LTC2909IDDB-3.3#TRMPBF belongs to ADI's precision power monitoring product line, engineered for high-accuracy, low-quiescent-current supervision of multiple voltage rails in mission-critical embedded systems.

FAQ

What is the guaranteed minimum VCC voltage for reset assertion in LTC2909IDDB-3.3#TRMPBF?

The LTC2909IDDB-3.3#TRMPBF guarantees RST assertion down to VCC = 0.5V across –40°C to +85°C, with VOL(RST) ≤ 0.15V at I_RST = 2500μA. This ensures reliable brownout detection even when bulk capacitance discharges deeply, a key requirement for automotive and industrial systems where supply collapse may be gradual.

How does the SEL pin configure input polarity for LTC2909IDDB-3.3#TRMPBF?

The SEL pin on LTC2909IDDB-3.3#TRMPBF selects polarity via three states: tied to VCC sets both ADJ1 and ADJ2 to positive polarity (UV detection), tied to GND sets both to negative polarity (UV detection on negative rails), and left open configures ADJ1 positive / ADJ2 negative - enabling simultaneous monitoring of one positive and one negative supply without external logic.

Can LTC2909IDDB-3.3#TRMPBF monitor a single supply for both undervoltage and overvoltage?

Yes, LTC2909IDDB-3.3#TRMPBF can monitor one supply for UV and OV using three external resistors and the REF pin. For a 3.3V rail, ADJ1 detects UV (via divider to GND) and ADJ2 detects OV (via divider referenced to REF), with SEL = VCC. The ±1.5% threshold accuracy ensures trip points remain outside the supply's tolerance band across temperature.

What is the function of the REF pin in LTC2909IDDB-3.3#TRMPBF?

The REF pin on LTC2909IDDB-3.3#TRMPBF provides a buffered 1.000V ±15mV output capable of sourcing/sinking 1mA. It serves as a precision offset for configuring ADJ2 to monitor negative supplies - e.g., connecting ADJ2 to a resistor divider between –5V and REF sets a –4.5V UV threshold - eliminating need for external reference ICs.

Does LTC2909IDDB-3.3#TRMPBF require an external timing capacitor for its 200ms reset timeout?

No, LTC2909IDDB-3.3#TRMPBF does not require an external timing capacitor for its 200ms reset timeout. When the TMR pin is tied directly to GND, the device automatically engages its internal 200ms timer - simplifying BOM and layout while maintaining guaranteed timing accuracy across temperature and voltage.