Analog Devices Inc. LTC2908IDDB-B1#TRMPBF

Overview

LTC2908IDDB-B1#TRMPBF from Analog Devices (formerly Linear Technology) is a precision six-input supply monitor IC designed for multivoltage systems requiring tight threshold accuracy and ultralow-voltage reset assertion. It monitors 3.3V, 2.5V, 1.8V, 1.5V, and two adjustable inputs (VADJ1/VADJ2) with ±1.5% threshold accuracy over –40°C to +85°C, features a 200ms reset timeout, and guarantees RST low down to VCC = 0.5V - enabling reliable power sequencing in network servers and optical networking equipment.

For engineers reviewing the LTC2908IDDB-B1#TRMPBF datasheet, LTC2908IDDB-B1#TRMPBF pinout, LTC2908IDDB-B1#TRMPBF application, or LTC2908IDDB-B1#TRMPBF equivalent, key selection criteria include its fixed 3.3V/2.5V/1.8V/1.5V monitoring set, dual 0.5V-adjustable thresholds, open-drain RST output with guaranteed low-state operation at 0.5V VCC, and DFN-8 (3mm × 2mm) package compatibility with space-constrained PCB layouts.

Technical Context

The LTC2908IDDB-B1#TRMPBF implements six independent voltage comparators referenced to a bandgap-derived 0.5V internal reference, with input-specific threshold scaling (e.g., V1 = 3.3V nominal → 3.086V typ). Its internal VCC auto-select logic uses the greater of V1 or V2 as the supply rail, enabling operation without external biasing.

Glitch immunity is achieved via dual-stage filtering: first-order lowpass integration at each comparator output plus a 200ms monostable reset pulse generator. The RST output combines a strong NMOS pull-down (typ. 40Ω on-resistance) and weak 6μA internal pull-up to VCC, supporting wired-OR configurations and external pull-up flexibility.

Key Specifications

Pinout & Package

Package: 8-lead (3mm × 2mm) plastic DFN (DDB8) with optional exposed pad (Pin 9) connected to GND for improved thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G33DBVR and MAX6816EUT+T, the LTC2908IDDB-B1#TRMPBF delivers integrated six-rail supervision with ±1.5% accuracy and 0.5V-minimum VCC operation - reducing component count, improving brownout resilience, and minimizing voltage margin overhead in dense multivoltage systems.

Availability

LTC2908IDDB-B1#TRMPBF is available at Aetrix Electronics and suitable for network servers, optical networking systems, and wireless base stations requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LTC2908IDDB-B1#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 acquired Linear Technology in 2017 and maintains its high-performance analog IC portfolio, emphasizing precision, reliability, and automotive/industrial qualification.

The LTC2908 product line delivers multirail supply monitoring with ±1.5% accuracy and ultralow-VCC reset for mission-critical infrastructure equipment where deterministic power sequencing and brownout resilience are mandatory.

FAQ

What is the operating temperature range for the LTC2908IDDB-B1#TRMPBF?

The LTC2908IDDB-B1#TRMPBF is rated for –40°C to +85°C operation (Industrial grade). This range is confirmed in the Absolute Maximum Ratings table and applies to all electrical specifications including ±1.5% threshold accuracy and 200ms reset timeout. The DFN-8 package supports this range with θJA = 76°C/W and an exposed pad option for enhanced thermal performance.

How does the LTC2908IDDB-B1#TRMPBF handle power-up sequencing for mixed-voltage systems?

During power-up, the LTC2908IDDB-B1#TRMPBF asserts RST low as soon as V1 or V2 reaches 0.5V, then holds RST low until all six inputs (3.3V, 2.5V, 1.8V, 1.5V, VADJ1, VADJ2) exceed their thresholds for a continuous 200ms period. This ensures synchronous release of system reset only after all rails stabilize, preventing partial initialization that could corrupt memory or lock peripherals.

Can the LTC2908IDDB-B1#TRMPBF monitor voltages other than its fixed thresholds?

Yes - the LTC2908IDDB-B1#TRMPBF includes two adjustable inputs (VADJ1 and VADJ2) with a precise 0.5V internal reference. By connecting each to a resistor divider from the target supply to ground (e.g., 12V → 0.5V), it can monitor custom voltages. Table 1 in the datasheet provides 1% resistor values for trip points from 0.6V to 12V, enabling flexible adaptation beyond the four fixed rails.

What is the minimum supply voltage required for the LTC2908IDDB-B1#TRMPBF to guarantee RST output functionality?

The LTC2908IDDB-B1#TRMPBF guarantees correct RST logic state (low output ≤0.15V) with VCC ≥ 0.5V, where VCC is the greater of V1 or V2. This ultralow-voltage capability is specified in the Electrical Characteristics table under "VCC Internal Supply Voltage" and ensures deterministic reset assertion even during severe brownout conditions where other supervisors fail.

Does the LTC2908IDDB-B1#TRMPBF require external timing components for its 200ms reset delay?

No - the LTC2908IDDB-B1#TRMPBF integrates the 200ms reset timeout capacitor internally. This eliminates the need for external timing capacitors or resistors, simplifying layout, reducing BOM count, and ensuring consistent delay timing across temperature and voltage variations without component tolerances affecting accuracy.