Analog Devices Inc. LTC2908CTS8-A1#TRMPBF

Overview

LTC2908CTS8-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 temperature, 200ms reset timeout, and guaranteed RST operation down to VCC = 0.5V. It is used in network servers and optical networking systems for reliable power-on reset and brownout detection.

For engineers reviewing the LTC2908CTS8-A1#TRMPBF datasheet, LTC2908CTS8-A1#TRMPBF pinout, LTC2908CTS8-A1#TRMPBF application, or LTC2908CTS8-A1#TRMPBF equivalent, key selection criteria include its fixed 5V/3.3V/2.5V/1.8V input thresholds, dual adjustable inputs, open-drain RST output with 0.15V low-level guarantee at 0.5V VCC, and TSOT-23-8 package compatibility with space-constrained PCB layouts.

Technical Context

The LTC2908CTS8-A1#TRMPBF implements six independent comparators referenced to a bandgap voltage, each with built-in glitch immunity via first-order low-pass filtering. Its internal VCC is auto-selected as the greater of V1 or V2, enabling self-powering from monitored rails without external bias.

Reset assertion requires all six inputs to remain above their respective thresholds for 200ms; any undervoltage event resets the timer. The RST output features a strong pull-down (40Ω typical) and weak internal 6μA pull-up to VCC, supporting wired-OR configurations and external pull-up flexibility for faster rise times.

Key Specifications

Pinout & Package

Package: 8-lead plastic TSOT-23 (ThinSOT™), 3mm × 1.75mm footprint, 1mm profile, lead-free (Pb-free) finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G33DBVR and MAX6816EUT+T, the LTC2908CTS8-A1#TRMPBF provides six-rail monitoring with dual adjustable inputs and superior ±1.5% accuracy-enabling consolidated supervision in multivoltage systems where board space and timing determinism are critical.

Availability

LTC2908CTS8-A1#TRMPBF is available at Aetrix Electronics and suitable for network servers, optical networking systems, and desktop computers requiring stable component supply, precise multirail monitoring, and commercial-temperature-grade reliability.

Supply support for LTC2908CTS8-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 LTC2908CTS8-A1#TRMPBF belongs to the LTC® precision supervisor family, engineered for high-accuracy, low-power, multivoltage system monitoring in telecom, computing, and industrial infrastructure equipment.

FAQ

What is the function of the VADJ1 and VADJ2 pins on the LTC2908CTS8-A1#TRMPBF?

The VADJ1 and VADJ2 pins on the LTC2908CTS8-A1#TRMPBF are adjustable voltage inputs, each internally referenced to a precise 0.5V comparator threshold. They accept external resistor dividers to monitor custom supply voltages (e.g., 1.05V, 1.2V, or 12V). When tied directly to ground, they default to monitoring 0.5V; when connected via a divider, the trip point is set by R1 = (VTRIP / 0.5V − 1) × R2, with R2 = 100kΩ recommended. This enables flexible rail coverage beyond the four fixed thresholds.

Does the LTC2908CTS8-A1#TRMPBF require an external timing capacitor for its 200ms reset timeout?

No, the LTC2908CTS8-A1#TRMPBF does not require an external timing capacitor. Its 200ms reset timeout is generated by an internal capacitor and timer circuit, eliminating the need for external components and reducing bill-of-materials count and PCB footprint. This internal timing is factory-trimmed and specified from 160ms to 260ms over temperature, with typical performance tightly centered at 200ms.

Can the RST output of the LTC2908CTS8-A1#TRMPBF drive a microcontroller's reset pin directly?

Yes, the RST output of the LTC2908CTS8-A1#TRMPBF can drive a microcontroller's reset pin directly, provided the MCU accepts an open-drain active-low input. The RST pin has a strong internal pull-down (guaranteed VOL ≤ 0.15V at 0.5V VCC) and a weak 6μA internal pull-up to VCC. For faster rise times or higher voltage levels (e.g., 3.3V or 5V pull-up), an external resistor to the target logic rail is recommended-but not required for basic functionality.

How does the LTC2908CTS8-A1#TRMPBF select its internal supply voltage (VCC)?

The LTC2908CTS8-A1#TRMPBF selects its internal supply voltage (VCC) automatically as the greater of the V1 and V2 input voltages. This self-biasing architecture eliminates the need for a dedicated VCC pin or external regulator. When V1 > V2, V1 powers the internal circuitry; when V2 > V1, V2 becomes VCC. Both pins must be bypassed with ≥0.1μF ceramic capacitors to ensure stable operation and noise immunity.

What is the minimum operating voltage required for the LTC2908CTS8-A1#TRMPBF to assert a valid logic-low RST?

The LTC2908CTS8-A1#TRMPBF guarantees a valid logic-low RST output (VOL ≤ 0.15V) with as little as 0.5V on either V1 or V2 - the greater of which serves as VCC. This ultralow-voltage capability ensures deterministic reset behavior during deep brownout conditions where other supervisors fail, making it especially valuable in systems with unregulated backup supplies or gradual power loss scenarios.