Analog Devices Inc. LTC2908ITS8-B1#TRMPBF

Overview

LTC2908ITS8-B1#TRMPBF from Analog Devices (formerly Linear Technology) is a precision six-input supply voltage supervisor IC designed for multivoltage systems requiring accurate, glitch-immune reset generation. 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 delivers active-low open-drain RST output with guaranteed operation down to VCC = 0.5V - enabling reliable power-up/power-down sequencing in network servers and optical networking equipment.

For engineers reviewing the LTC2908ITS8-B1#TRMPBF datasheet, LTC2908ITS8-B1#TRMPBF pinout, LTC2908ITS8-B1#TRMPBF application, or LTC2908ITS8-B1#TRMPBF equivalent, key selection considerations include its fixed 3.3V/2.5V/1.8V/1.5V monitoring thresholds, dual adjustable inputs referenced to 0.5V, ultralow-voltage RST pull-down capability, and compatibility with wired-OR reset bus architectures across multiple supervisors.

Technical Context

The LTC2908ITS8-B1#TRMPBF implements six independent high-accuracy comparators with internal bandgap reference and first-order low-pass filtering per input to suppress supply noise transients. Its reset logic requires all six monitored voltages to remain above their respective thresholds for a full 200ms before releasing RST, preventing false resets during brownouts or ripple-induced dips.

VCC is auto-selected as the greater of V1 or V2 (both rated up to 6V), powering internal circuitry including the 6μA weak pull-up on RST and the 200ms timer. Input currents are ultra-low: ≤24μA on V1, ≤8μA on V2, ≤2μA on V3/V4, and ±15nA on VADJ1/VADJ2 - minimizing loading on sensitive power rails.

Key Specifications

Pinout & Package

Package: 8-lead plastic TSOT-23 (ThinSOT™), 3mm × 1.75mm footprint, 1mm profile - optimized for space-constrained PCB layouts in dense server and telecom modules.

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 LTC2908ITS8-B1#TRMPBF uniquely integrates six precisely calibrated thresholds-including native 1.5V and 1.8V-into a single TSOT-23 package with superior ±1.5% accuracy and guaranteed 0.5V RST operation, making it optimal for compact, high-reliability multirail systems where timing synchronization and brownout resilience are critical.

Availability

LTC2908ITS8-B1#TRMPBF is available at Aetrix Electronics and suitable for network servers, optical networking systems, and wireless base stations requiring stable component supply, long-term lifecycle support, and guaranteed performance across –40°C to +85°C industrial temperature range.

Supply support for LTC2908ITS8-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, Inc. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors for precision instrumentation, communications, and industrial applications.

The LTC2908ITS8-B1#TRMPBF belongs to Linear Technology's precision power monitoring product line, engineered specifically for high-density computing and telecom infrastructure where accurate, noise-immune, multirail supervision is essential for system reliability.

FAQ

What voltage rails does the LTC2908ITS8-B1#TRMPBF monitor by default?

The LTC2908ITS8-B1#TRMPBF is the B1 variant and monitors 3.3V (V1), 2.5V (V2), 1.8V (V3), 1.5V (V4), and two adjustable inputs (VADJ1, VADJ2) referenced to 0.5V. It does not support the 5V or C1-series 2.5V+five-adjustable configurations. Each fixed threshold has ±1.5% accuracy over –40°C to +85°C.

Can the LTC2908ITS8-B1#TRMPBF operate with only four supply rails?

Yes. Unused inputs (e.g., V3, V4, VADJ1, VADJ2) on the LTC2908ITS8-B1#TRMPBF should be tied to the nearest higher available supply voltage - for example, connect V4 (1.5V input) to the 1.8V rail if only monitoring 3.3V, 2.5V, and 1.8V. This ensures comparator inputs remain within valid operating range and avoids floating nodes.

What is the minimum supply voltage required for the RST output to function correctly on the LTC2908ITS8-B1#TRMPBF?

The LTC2908ITS8-B1#TRMPBF guarantees correct RST logic state - specifically, a valid low-level output (VOL ≤ 0.15V) - as long as V1 and/or V2 is ≥ 0.5V. This ultralow-voltage capability ensures reliable reset assertion during severe brownout conditions where other supervisors would float or release prematurely.

How does the LTC2908ITS8-B1#TRMPBF prevent false resets due to supply noise?

The LTC2908ITS8-B1#TRMPBF employs dual noise mitigation: (1) first-order low-pass filtering on each comparator output to reject short transients, and (2) a 200ms reset timeout that ignores supply disturbances faster than 5Hz. Together, these ensure RST only responds to sustained undervoltage events - not ripple or switching noise - without sacrificing ±1.5% threshold accuracy.

Is the LTC2908ITS8-B1#TRMPBF pin-compatible with other LTC2908 variants?

No. While the LTC2908ITS8-B1#TRMPBF shares the same TSOT-23-8 package and pinout with other TSOT-23 variants (e.g., LTC2908ITS8-A1, LTC2908ITS8-C1), the internal threshold mapping differs: B1 uses 3.3V/2.5V/1.8V/1.5V, A1 uses 5V/3.3V/2.5V/1.8V, and C1 uses 2.5V + five adjustable inputs. Swapping variants requires schematic and layout review.