Analog Devices Inc. LTC2908IDDB-A1#TRMPBF

Overview

LTC2908IDDB-A1#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 5V, 3.3V, 2.5V, 1.8V, and two adjustable inputs (VADJ1/VADJ2) with ±1.5% threshold accuracy over –40°C to +85°C, 200ms reset timeout, and guaranteed RST pull-down down to VCC = 0.5V. It serves as a system-level power supervisor in network servers and optical networking equipment.

For engineers reviewing the LTC2908IDDB-A1#TRMPBF datasheet, LTC2908IDDB-A1#TRMPBF pinout, LTC2908IDDB-A1#TRMPBF application, or LTC2908IDDB-A1#TRMPBF equivalent, key selection criteria include its fixed 5V/3.3V/2.5V/1.8V thresholds, dual adjustable inputs, open-drain RST output with 0.5V minimum operating voltage, and DFN-8 (3mm × 2mm) package compatibility with space-constrained PCB layouts.

Technical Context

The LTC2908IDDB-A1#TRMPBF implements six independent comparators referenced to a bandgap-derived 0.5V internal reference, with input-specific threshold scaling. Its internal VCC auto-select logic uses the greater of V1 or V2 as the supply rail, enabling operation across mixed-voltage domains without external biasing.

Glitch immunity is achieved via integrated first-order low-pass filtering at each comparator output plus a 200ms monostable reset pulse generator. The RST output features 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 for faster rise times.

Key Specifications

Pinout & Package

Package: 8-lead (3mm × 2mm) plastic DFN (DDB8), 1mm profile, exposed pad (Pin 9, optional GND connection).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G18DBVR and MAX6326UT29D3+T, the LTC2908IDDB-A1#TRMPBF provides true six-rail visibility, ±1.5% accuracy, and dual adjustable inputs - making it uniquely suitable for complex multivoltage systems where coordinated reset sequencing and custom threshold flexibility are mandatory.

Availability

LTC2908IDDB-A1#TRMPBF is available at Aetrix Electronics and suitable for network servers, optical networking systems, and desktop/notebook computers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LTC2908IDDB-A1#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. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors.

The LTC2908 product line delivers precision, low-power, multirail supply monitoring ICs optimized for telecom, computing, and industrial systems demanding tight threshold accuracy and robust noise immunity.

FAQ

What is the operating temperature range for the LTC2908IDDB-A1#TRMPBF?

The LTC2908IDDB-A1#TRMPBF is rated for industrial operation from –40°C to +85°C. This extended temperature range ensures reliable performance in demanding environments such as base station enclosures and network server chassis where ambient temperatures exceed commercial limits. The ±1.5% threshold accuracy specification is guaranteed across this full range, unlike many competitors that only specify accuracy at 25°C.

How does the LTC2908IDDB-A1#TRMPBF handle power-up sequencing with multiple supply rails?

The LTC2908IDDB-A1#TRMPBF asserts RST low immediately upon detecting ≥200mV on V1 or V2 and holds it low until all six inputs exceed their respective thresholds for a continuous 200ms period. This ensures synchronized release from reset only after all monitored rails have stabilized - critical for FPGAs, processors, and memory subsystems requiring strict power sequencing compliance.

Can the LTC2908IDDB-A1#TRMPBF monitor non-standard supply voltages like 4.2V or 2.85V?

Yes - the LTC2908IDDB-A1#TRMPBF includes two adjustable inputs (VADJ1 and VADJ2) referenced to an internal 0.5V comparator threshold. By connecting each to a resistor divider between the target rail and ground, custom trip points from 0.6V to 12V can be implemented. For example, a 4.2V rail uses R1 = 768kΩ and R2 = 100kΩ (1% values) to achieve a 4.2V ±5% threshold.

What is the minimum supply voltage required for the RST output to remain functional on the LTC2908IDDB-A1#TRMPBF?

The LTC2908IDDB-A1#TRMPBF guarantees correct RST logic state (low impedance pull-down) with VCC ≥ 0.5V, where VCC is the greater of V1 or V2. At VCC = 0.5V, RST pulls low to ≤0.15V with 5μA sink current - enabling reliable reset assertion during deep brownout events where other supervisors fail.

Is the LTC2908IDDB-A1#TRMPBF pin-compatible with other variants in the LTC2908 family?

Yes - all LTC2908 variants (A1/B1/C1) in the DFN-8 (DDB8) package share identical pinouts and footprints. The LTC2908IDDB-A1#TRMPBF, LTC2908IDDB-B1#TRMPBF, and LTC2908IDDB-C1#TRMPBF differ only in preconfigured fixed thresholds (A1: 5V/3.3V/2.5V/1.8V; B1: 3.3V/2.5V/1.8V/1.5V; C1: 2.5V + five adjustable), allowing drop-in replacement within the same package variant.