Analog Devices Inc. LTC1727ES8-5#PBF

Overview

LTC1727ES8-5#PBF from Analog Devices is a micropower precision triple supply monitor IC in an 8-lead SO package, designed to simultaneously monitor 5V, 3.3V, and an adjustable supply (VCCA) with ±1.5% threshold accuracy over temperature. It provides individual open-drain comparator outputs (COMP5, COMP3, COMPA) plus a common active-low reset output (RST) with 200ms delay, ensuring reliable power-on reset for multi-rail systems such as notebook computers and intelligent instruments.

For engineers reviewing the LTC1727ES8-5#PBF datasheet, LTC1727ES8-5#PBF pinout, LTC1727ES8-5#PBF application, or LTC1727ES8-5#PBF equivalent, this device supports flexible supply monitoring configurations-including dual-supply setups with VCCA tied to feedback dividers-and guarantees RST assertion down to 1V on any monitored rail, critical for brownout immunity in battery-powered and industrial embedded designs.

Technical Context

The LTC1727ES8-5#PBF implements three independent voltage comparators feeding into a 200ms reset timer and logic OR gate, with internal bandgap reference enabling accurate trip-point detection. Its power-detect architecture dynamically selects VCC3 or VCC5 as the supply source depending on which voltage is higher, ensuring RST remains valid even during asymmetric power-up sequences.

All comparator outputs (COMP5, COMP3, COMPA) are open-drain with weak internal 6µA pull-ups to VCC3 and support external pull-up to voltages exceeding VCC3-enabling direct interfacing with 5V logic. The RST output is guaranteed functional for VCC3 ≥ 1V or VCC5 ≥ 1V, and its glitch immunity includes both input hysteresis (10% of threshold) and fixed 200ms pulse width debouncing.

Key Specifications

Pinout & Package

Package: 8-Lead Plastic SO (S8), 0.150-inch narrow body, JEDEC MS-012AC compliant, with θJA = 150°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC1326-5 and LTC1726-5, the LTC1727ES8-5#PBF delivers deterministic 200ms reset timing without external components and provides per-rail status visibility via dedicated open-drain outputs-making it optimal for debug-rich, cost-sensitive, and thermally demanding applications where fixed timing and diagnostic capability are essential.

Availability

LTC1727ES8-5#PBF 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 LTC1727ES8-5#PBF 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 series belongs to Analog Devices' precision power monitoring product line, engineered specifically for reliable multi-rail system supervision in computing and instrumentation applications where accuracy, low power, and robustness against supply transients are mandatory.

FAQ

What is the operating temperature range for the LTC1727ES8-5#PBF?

The LTC1727ES8-5#PBF is rated for operation from –40°C to +85°C (E-grade), with full electrical specifications guaranteed across this range-including ±1.5% threshold accuracy and 200ms reset timing. This makes LTC1727ES8-5#PBF suitable for commercial and industrial environments where thermal stability is critical.

Can the LTC1727ES8-5#PBF monitor only two supplies instead of three?

Yes, the LTC1727ES8-5#PBF can be configured to monitor just two supplies-for example, by tying VCCA to VCC3 or VCC5, effectively disabling the adjustable rail monitor while retaining 5V and 3.3V supervision. The RST output still requires both active rails to exceed their thresholds for 200ms before deassertion, preserving system reliability.

How does the VCC5 override function work in the LTC1727ES8-5#PBF?

The LTC1727ES8-5#PBF disables VCC5 monitoring when VCC5 is within ±25mV of VCC3 and below ~4.15V, allowing it to behave as a 3.3V-only monitor. When VCC5 exceeds ~4.15V while matching VCC3, the 5V trip point re-enables. This dual-mode behavior lets LTC1727ES8-5#PBF serve as a single-supply monitor without hardware changes.

What is the minimum supply voltage required to guarantee correct RST output state for the LTC1727ES8-5#PBF?

The LTC1727ES8-5#PBF guarantees correct RST logic state for VCC3 ≥ 1V or VCC5 ≥ 1V. Below 1V on both pins, RST is not guaranteed-ensuring fail-safe behavior during deep brownout. This 1V lower limit is explicitly specified and tested, making LTC1727ES8-5#PBF highly resilient in low-voltage edge cases.

Does the LTC1727ES8-5#PBF require external capacitors, and if so, where?

Yes, the LTC1727ES8-5#PBF requires ≥0.1µF ceramic bypass capacitors from VCC3 to GND and from VCC5 to GND, as specified in the datasheet. These capacitors stabilize internal reference and comparator operation, suppress supply noise, and prevent false triggering-omitting them compromises the ±1.5% accuracy and glitch immunity of LTC1727ES8-5#PBF.