Analog Devices Inc. LTC2903CS6-A1#TRMPBF

Overview

LTC2903CS6-A1#TRMPBF from Analog Devices (formerly Linear Technology) is a precision quad supply monitor IC in 6-lead TSOT-23 package, designed to supervise 3.3V, 2.5V, 1.8V, and adjustable (ADJ) voltage rails simultaneously. It guarantees ±1.5% threshold accuracy over temperature, features 200ms reset timeout, active-low open-drain RST output, and ultralow 20µA quiescent current - enabling reliable power-up sequencing in multivoltage telecom and server systems.

For engineers reviewing the LTC2903CS6-A1#TRMPBF datasheet, LTC2903CS6-A1#TRMPBF pinout, LTC2903CS6-A1#TRMPBF application, or LTC2903CS6-A1#TRMPBF equivalent, key selection criteria include its guaranteed 0.5V minimum VCC operation, four independent undervoltage detection channels with fixed/adjustable thresholds, SOT-23 footprint compatibility, and immunity to supply glitches during brownout conditions.

Technical Context

The LTC2903CS6-A1#TRMPBF implements four independent comparators referenced to an internal bandgap, each monitoring a dedicated input (V1–V4) against factory-trimmed thresholds: 2.921V (3.3V, 10%), 2.213V (2.5V, 10%), 1.593V (1.8V, 10%), and 0.500V (ADJ). Internal VCC is autonomously generated from the higher of V1 or V2, enabling operation down to 0.5V on any monitored rail.

A 200ms reset delay timer ensures stable assertion of the open-drain RST output only after all four inputs remain above threshold for the full duration. The RST pin includes a weak internal pull-up to V2 (10µA typical), low-voltage pull-down capability down to 0.2V, and glitch immunity via comparator transient filtering and reset timeout hysteresis.

Key Specifications

Pinout & Package

Package: 6-lead plastic TSOT-23 (0.95mm pitch, 1.00mm max height), JEDEC MO-193 compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC2903CS6-B1#TRMPBF, the LTC2903CS6-A1#TRMPBF provides adjustable V4 monitoring at the cost of fixed 3.3V/2.5V/1.8V thresholds, while LTC2900CS6#TRMPBF trades factory-trimmed accuracy for programmability - making LTC2903CS6-A1#TRMPBF optimal for production systems with known, mixed fixed/adjustable rail requirements.

Availability

LTC2903CS6-A1#TRMPBF is available at Aetrix Electronics and suitable for optical networking systems, cell phone base stations, and network servers requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for LTC2903CS6-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 acquired Linear Technology in 2017, inheriting its precision analog and power management portfolio including high-reliability supervisors.

The LTC2903 family was engineered specifically for multivoltage systems in telecom infrastructure, delivering guaranteed sub-1V reset operation and ±1.5% accuracy without hysteresis-induced error - addressing the stringent sequencing needs of FPGAs, ASICs, and high-speed SerDes.

FAQ

What is the guaranteed minimum operating voltage for LTC2903CS6-A1#TRMPBF?

The LTC2903CS6-A1#TRMPBF guarantees full functionality down to 0.5V on its internal VCC supply, which is derived from the higher of V1 or V2. This enables the RST output to remain asserted even during deep brownout conditions on primary rails - a critical feature for fail-safe operation in telecom equipment where partial power loss must trigger controlled shutdown.

How does LTC2903CS6-A1#TRMPBF achieve ±1.5% threshold accuracy without hysteresis?

The LTC2903CS6-A1#TRMPBF avoids hysteresis by using proprietary comparator transient filtering that rejects short-duration noise spikes (<150µs), combined with a 200ms reset timeout that acts as a second-stage digital filter. This architecture preserves the ±1.5% threshold specification across temperature while preventing spurious resets - unlike hysteresis-based supervisors that degrade stated accuracy by up to 2.5%.

Can LTC2903CS6-A1#TRMPBF monitor negative voltages like –5.2V?

No, the LTC2903CS6-A1#TRMPBF is configured for positive rails only (3.3V, 2.5V, 1.8V, ADJ). For –5.2V monitoring, the LTC2903CS6-C1 variant is required - it features a dedicated V4 input rated from –6.5V to 0.3V with a –4.602V threshold. Using LTC2903CS6-A1#TRMPBF for negative supplies would violate absolute maximum ratings and cause permanent damage.

What is the purpose of the V3 pin on LTC2903CS6-A1#TRMPBF?

The V3 pin on LTC2903CS6-A1#TRMPBF monitors the 1.8V rail and actively assists the RST pull-down circuitry below 1V. When V1, V2, or V3 drops below threshold, the device uses current from all three pins to strengthen the RST sink capability - enabling reliable reset assertion down to 0.2V VCC. This triple-input pull-down is unique to A1/B1/C1 variants and not present in D1/E1 versions.

Does LTC2903CS6-A1#TRMPBF require external pull-up resistors on the RST pin?

The LTC2903CS6-A1#TRMPBF includes a weak internal 10µA pull-up to V2, sufficient for basic CMOS reset inputs. However, an external pull-up is recommended when interfacing with TTL logic, driving capacitive loads >50pF, or requiring rise times <1µs - especially when pulling RST to a voltage higher than V2, as the internal pull-up cannot exceed V2.