Analog Devices Inc. LTC1727IS8-2.5#TRPBF

Overview

LTC1727IS8-2.5#TRPBF from Analog Devices is a micropower precision triple supply monitor IC in 8-lead SO package, designed for systems requiring simultaneous monitoring of 2.5V, 3.3V, and an adjustable supply (1.0V threshold). It delivers ±1.5% threshold accuracy over temperature, 200ms reset delay, and individual open-drain comparator outputs (COMP3, COMP25, COMPA) plus a common active-low RST output. Used in notebook computers and intelligent instruments where reliable power-up sequencing and brownout detection are critical.

For engineers reviewing the LTC1727IS8-2.5#TRPBF datasheet, LTC1727IS8-2.5#TRPBF pinout, LTC1727IS8-2.5#TRPBF application, or LTC1727IS8-2.5#TRPBF equivalent, key selection criteria include VCC25/VCC3/VCCA trip thresholds (2.338V/3.086V/1.000V), guaranteed RST assertion down to 1V supply, 10µA typical supply current, and glitch-immune 200ms reset timing.

Technical Context

The LTC1727IS8-2.5#TRPBF implements three independent voltage comparators with internal bandgap reference, each feeding into a 200ms monostable pulse generator that controls the shared RST output. Its power-detect architecture selects VCC3 or VCC25 as the primary supply based on which voltage is higher, ensuring RST remains asserted until all three inputs exceed their respective thresholds and remain stable for 200ms.

Each comparator output (COMP3, COMP25, COMPA) is open-drain with weak internal 6µA pull-up to VCC3 and operates independently - COMP3 asserts high when VCC3 > 3.086V, COMP25 when VCC25 > 2.338V, and COMPA when VCCA > 1.000V. The RST output requires both VCC3 ≥ 1V and VCC25 ≥ 1V to guarantee correct logic state during low-voltage conditions.

Key Specifications

Pinout & Package

Package: 8-Lead Plastic SO (S8), 0.150-inch narrow body, RoHS-compliant, rated for –40°C to 85°C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC1326-2.5 and LTC1726-2.5, the LTC1727IS8-2.5#TRPBF offers dedicated per-rail status outputs and guaranteed 1V RST operation - critical for brownout resilience in cost-sensitive industrial designs where watchdog functionality is handled separately.

Availability

LTC1727IS8-2.5#TRPBF is available at Aetrix Electronics and suitable for desktop computers, notebook computers, and intelligent instruments requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for LTC1727IS8-2.5#TRPBF 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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LTC1727 product line delivers micropower precision supply monitoring ICs optimized for multi-rail embedded systems requiring deterministic reset behavior, low quiescent current, and robust brownout immunity.

FAQ

What is the function of the VCCA pin on the LTC1727IS8-2.5#TRPBF?

The VCCA pin on the LTC1727IS8-2.5#TRPBF is a high-impedance input with a fixed 1.000V threshold used to monitor an adjustable supply rail, such as a DC/DC converter feedback node. When VCCA exceeds 1.000V, the COMPA output goes high. If unused, VCCA may be tied to VCC3 or VCC25 without affecting LTC1727IS8-2.5#TRPBF operation.

Does the LTC1727IS8-2.5#TRPBF require external pull-up resistors on its open-drain outputs?

The LTC1727IS8-2.5#TRPBF includes internal 6µA weak pull-ups to VCC3 on RST, COMP3, COMP25, and COMPA. External pull-ups are optional but recommended when interfacing with 5V logic or when faster rise times are needed. The LTC1727IS8-2.5#TRPBF datasheet specifies VOL ≤ 0.05V at 100µA sink with internal pull-up active.

What is the minimum supply voltage required to guarantee correct RST output behavior for the LTC1727IS8-2.5#TRPBF?

The LTC1727IS8-2.5#TRPBF guarantees correct RST logic state for VCC3 ≥ 1V or VCC25 ≥ 1V. Below 1V, RST behavior is not specified. This 1V minimum ensures reliable brownout detection in systems where supply rails dip below nominal values during transient load events.

How does the LTC1727IS8-2.5#TRPBF handle power sequencing when both VCC3 and VCC25 are present?

The LTC1727IS8-2.5#TRPBF automatically selects the higher of VCC3 or VCC25 as its internal power source. If VCC25 rises first, it powers the device and enables RST assertion once VCC25 reaches 1V. The LTC1727IS8-2.5#TRPBF then monitors both rails and releases RST only after both exceed their thresholds and remain stable for 200ms.

Can the LTC1727IS8-2.5#TRPBF be used to monitor only two supplies instead of three?

Yes, the LTC1727IS8-2.5#TRPBF supports dual-supply monitoring by tying the unused VCCA pin to VCC3 or VCC25. For example, connecting VCCA to VCC3 disables the adjustable rail monitor while retaining 2.5V and 3.3V supervision. The LTC1727IS8-2.5#TRPBF RST output will release only after both active supplies meet their thresholds and stabilize for 200ms.