Analog Devices Inc. LTC2909IDDB-5#TRM

Overview

LTC2909IDDB-5#TRM from Analog Devices (formerly Linear Technology) is a precision triple-input voltage monitor IC for system power supervision, featuring dual adjustable 0.5V-threshold inputs with pin-selectable polarity, a fixed 4.425V VCC UVLO threshold (±1.5% accuracy), 200ms internal reset timeout, and open-drain RST output. It operates down to 0.5V VCC and supports positive/negative supply monitoring in desktop computers, network servers, and automotive ECUs.

For engineers reviewing the LTC2909IDDB-5#TRM datasheet, LTC2909IDDB-5#TRM pinout, LTC2909IDDB-5#TRM application, or LTC2909IDDB-5#TRM equivalent, key selection considerations include guaranteed 0.5V ADJ input threshold accuracy over –40°C to +85°C, 50μA quiescent current, 6.5V internal shunt regulator capability, and SEL/TMR pin configuration for polarity and timeout mode selection.

Technical Context

The LTC2909IDDB-5#TRM integrates two independent 0.5V comparator inputs with programmable polarity via the three-state SEL pin (VCC/GND/open), enabling simultaneous UV/OV detection on positive or negative rails. Its third fixed UVLO channel monitors VCC at 4.425V (11.5% below 5V nominal) with ±1.5% accuracy across temperature.

Reset assertion is synchronized across all three channels, with timeout configurable as internal 200ms (TMR = GND), external capacitor-based (9ms/nF), or disabled (TMR = VCC). The buffered 1.000V REF output enables offset-based negative rail monitoring without external components.

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 voltage monitor applications.

Compared with LTC2909CDDB-5#TRM, the LTC2909IDDB-5#TRM extends operational reliability to –40°C, critical for automotive and industrial edge devices; versus TPS3808G33DBVR, it delivers triple-input flexibility, polarity configurability, and buffered reference-enabling compact, single-chip supervision of complex multi-rail systems.

Availability

LTC2909IDDB-5#TRM is available at Aetrix Electronics and suitable for desktop computers, network servers, and automotive electronic control units requiring stable component supply across extended temperature ranges.

Supply support for LTC2909IDDB-5#TRM 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 acquired Linear Technology in 2017 and maintains its high-precision analog and power management product lines.

The LTC2909IDDB-5#TRM belongs to Linear's precision voltage supervisor family, designed specifically for reliable multi-rail power sequencing and fault detection in computing, communications, and automotive systems.

FAQ

What is the guaranteed minimum VCC voltage for LTC2909IDDB-5#TRM reset assertion?

The LTC2909IDDB-5#TRM guarantees RST remains asserted down to VCC = 0.5V, ensuring reliable brownout detection even during severe supply collapse. This specification is tested and guaranteed over the full –40°C to +85°C industrial temperature range, and applies regardless of ADJ1/ADJ2 input states or SEL configuration. The 0.5V minimum enables use in ultra-low-voltage backup domains where other supervisors fail.

How does the SEL pin configure polarity for ADJ1 and ADJ2 on LTC2909IDDB-5#TRM?

On the LTC2909IDDB-5#TRM, the SEL pin selects one of three polarity combinations: SEL = VCC configures both ADJ1 and ADJ2 for positive polarity (UV on rising edge, OV on falling edge); SEL = GND configures both for negative polarity (UV on falling edge, OV on rising edge); SEL open configures ADJ1 positive and ADJ2 negative. Each configuration is validated in the datasheet's Table 1 and requires no external components.

What is the accuracy of the VCC UVLO threshold for LTC2909IDDB-5#TRM?

The VCC UVLO threshold for LTC2909IDDB-5#TRM is 4.425V with ±1.5% accuracy over the full –40°C to +85°C temperature range. This corresponds to 11.5% below the nominal 5V supply, and is guaranteed by production testing. The same ±1.5% tolerance applies to the 0.5V ADJ input thresholds, enabling consistent system-level fault margin design across all monitored rails.

Can LTC2909IDDB-5#TRM monitor a negative supply without external references?

Yes - the LTC2909IDDB-5#TRM includes a buffered 1.000V REF output that serves as a stable offset for negative-supply monitoring. When ADJ1 or ADJ2 is configured for negative polarity (via SEL), the input connects between the negative rail and REF instead of ground, enabling direct UV/OV detection on rails like –5V or –12V using only two external resistors per input.

What reset timeout options are available on LTC2909IDDB-5#TRM and how are they selected?

The LTC2909IDDB-5#TRM offers three reset timeout modes selected via the TMR pin: tying TMR to GND enables a guaranteed 200ms internal timeout; connecting a capacitor from TMR to GND sets timeout at 9ms/nF (e.g., 2.2nF = 20ms); tying TMR to VCC disables timeout and places the device in comparator mode, where RST responds immediately to input faults without delay.