Analog Devices Inc. LTC2909IDDB-5#TRPBF

Overview

LTC2909IDDB-5#TRPBF from Analog Devices (acquired Linear Technology) is a precision dual adjustable-input undervoltage/overvoltage monitor with integrated 5V UVLO, buffered 1V reference, and open-drain reset output. It features ±1.5% threshold accuracy over –40°C to +85°C, 50μA quiescent current, 6.5V shunt regulator, and pin-selectable input polarity for monitoring positive or negative rails. Used in core voltage supervision of 5V logic systems in network servers and industrial controllers.

For engineers reviewing the LTC2909IDDB-5#TRPBF datasheet, LTC2909IDDB-5#TRPBF pinout, LTC2909IDDB-5#TRPBF application, or LTC2909IDDB-5#TRPBF equivalent, key selection criteria include guaranteed 0.5V ADJ input threshold accuracy, VCC UVLO at 4.350–4.500V, internal 200ms timeout capability, SEL pin polarity configuration, and TSOT-23/DFN package compatibility with space-constrained PCB layouts.

Technical Context

The LTC2909IDDB-5#TRPBF implements two independent 0.5V threshold comparators with polarity controlled by the three-state SEL pin (VCC/Open/GND), enabling flexible UV/OV detection on positive or negative supplies. Its third fixed-threshold monitor on VCC provides accurate 5V system UVLO (4.350–4.500V) with ±1.5% tolerance across temperature.

Reset timing is configurable via TMR pin: tied to GND enables 200ms internal timeout; connected to capacitor yields 9ms/nF external timeout; tied to VCC disables timeout and enters comparator mode. The buffered 1V REF output supports offset-based negative rail monitoring and drives up to 1mA load.

Key Specifications

Pinout & Package

Package: 8-lead 3mm × 2mm DFN (DDB) with exposed pad; RoHS-compliant, lead-free, tape-and-reel (#TRPBF).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6316H_05D3+T and TPS3808G33DBVR, the LTC2909IDDB-5#TRPBF uniquely integrates dual adjustable inputs, pin-selectable polarity, buffered 1V reference, and 5V UVLO in one DFN package-enabling compact, flexible supervision of mixed-polarity rails without external components.

Availability

LTC2909IDDB-5#TRPBF is available at Aetrix Electronics and suitable for network server power management, industrial PLC voltage supervision, and automotive infotainment core supply monitoring requiring stable component supply and long-term lifecycle support.

Supply support for LTC2909IDDB-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 supervisors for mission-critical embedded systems where accuracy, reliability, and board space efficiency are essential design constraints.

FAQ

What is the guaranteed operating supply voltage range for the LTC2909IDDB-5#TRPBF?

The LTC2909IDDB-5#TRPBF operates from VCC = 0.5V minimum, with guaranteed reset assertion down to this level. Its VCC pin supports direct connection to supplies up to 6V; above 6V, a series current-limiting resistor must be used due to the internal 6.5V shunt regulator. Absolute maximum VCC is 6V for direct connection, or higher with proper resistor sizing per datasheet Equation 1.

How does the SEL pin configure input polarity on the LTC2909IDDB-5#TRPBF?

The SEL pin on the LTC2909IDDB-5#TRPBF selects ADJ1/ADJ2 polarity: connected to VCC sets both inputs for positive polarity (UV/OV detection on positive rails); left open sets both for negative polarity (UV/OV on negative rails); connected to GND configures ADJ1 for positive and ADJ2 for negative polarity. Leakage current remains within ±25μA across all states, ensuring robust interfacing with microcontrollers or discrete logic.

Can the LTC2909IDDB-5#TRPBF monitor a single supply for both undervoltage and overvoltage conditions?

Yes, the LTC2909IDDB-5#TRPBF can monitor one supply for UV and OV using three external resistors and the REF pin. For a positive 5V supply, ADJ1 detects UV and ADJ2 detects OV (or vice versa) by configuring resistor dividers referenced to GND and REF respectively. Example values for ±5% tolerance are provided in datasheet Table 3, enabling window monitoring without additional ICs.

What is the purpose of the buffered 1V reference (REF pin) on the LTC2909IDDB-5#TRPBF?

The REF pin on the LTC2909IDDB-5#TRPBF provides a precision 0.985–1.015V buffered output capable of sourcing/sinking 1mA. It serves as an offset voltage for negative-supply monitoring-enabling resistor dividers between VMON and REF to generate correct 0.5V comparator thresholds. This eliminates the need for external references or op-amps in dual-polarity supervision designs.

Does the LTC2909IDDB-5#TRPBF support reset timeout configuration without external components?

Yes, the LTC2909IDDB-5#TRPBF supports timeout configuration without external components: tying the TMR pin to GND activates the factory-trimmed internal 200ms timeout. This eliminates timing capacitors and associated layout sensitivity, simplifying design for standard 5V system supervision. The timeout remains accurate across –40°C to +85°C with ±30ms variation (150–260ms).