Analog Devices Inc. LTC1728HS5-5#TRPBF

Overview

LTC1728HS5-5#TRPBF from Analog Devices is a micropower precision triple supply monitor in 5-lead SOT-23 package, designed to simultaneously monitor 5V, 3.3V, and an adjustable input (VCCA) with ±1.5% threshold accuracy over temperature. It provides a single active-low open-drain RESET output with 200ms delay, guaranteed operation down to 1V supply, and consumes only 10µA typical supply current. It is used in power-up sequencing and brownout protection for embedded computing systems.

For engineers reviewing the LTC1728HS5-5#TRPBF datasheet, LTC1728HS5-5#TRPBF pinout, LTC1728HS5-5#TRPBF application, or LTC1728HS5-5#TRPBF equivalent, this page delivers verified specifications, thermal-grade packaging details (–40°C to 125°C), reset timing behavior, VCC override logic for 5V/3.3V dual-mode operation, and real-world supply monitoring configurations.

Technical Context

The LTC1728HS5-5#TRPBF implements a triple-input comparator architecture with internal bandgap reference and 200ms power-on reset timer. All three inputs-VCC5 (5V), VCC3 (3.3V), and VCCA (adjustable)-must exceed their respective thresholds (4.675V, 3.086V, 1.000V) before RST deasserts; any undervoltage reasserts RST after 110µs detection latency.

Its power-detect logic selects the highest-voltage valid supply (VCC5 or VCC3) as internal power source, ensuring RST remains low until ≥1V on either rail. The 5V version includes VCC5 reset override functionality: when VCC5 ≈ VCC3 ±25mV and <4.15V, the 5V trip point is disabled, enabling automatic 3.3V-only mode during slow-ramp conditions.

Key Specifications

Pinout & Package

The LTC1728HS5-5#TRPBF uses a 5-lead TSOT-23 (S5) plastic package with 0.95mm body width, 1.90mm length, and 0.30–0.45mm lead pitch. Pin 1 is RST (active-low reset output), Pin 2 is GND, Pin 3 is VCCA (adjustable threshold input), Pin 4 is VCC5/VCC25/VCC18 (5V sense/power input), and Pin 5 is VCC3 (3.3V sense/power input).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC1728ES5-5#TRPBF, the LTC1728HS5-5#TRPBF adds 37°C higher max operating temperature for mission-critical thermal environments; compared with LTC1326-5#TRPBF, it trades watchdog capability and tighter accuracy for smaller size, lower cost, and simpler integration in fixed-timing applications.

Availability

LTC1728HS5-5#TRPBF is available at Aetrix Electronics and suitable for desktop computers, notebook computers, and network servers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LTC1728HS5-5#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 LTC1728 belongs to Analog Devices' precision power monitoring product line, engineered for reliable, low-power supply supervision in thermally demanding embedded systems where deterministic reset behavior is critical.

FAQ

What is the operating temperature range of the LTC1728HS5-5#TRPBF?

The LTC1728HS5-5#TRPBF is rated for –40°C to +125°C (H-grade), making it suitable for under-hood automotive modules, industrial PLCs, and high-ambient embedded controllers where extended thermal performance is mandatory. This exceeds the –40°C to +85°C rating of the E-grade LTC1728ES5-5#TRPBF variant.

How does the VCC5 override function work in the LTC1728HS5-5#TRPBF?

The LTC1728HS5-5#TRPBF disables its 5V trip point when VCC5 is within ±25mV of VCC3 and below ~4.15V, automatically switching to 3.3V-only monitoring mode. This prevents spurious RST deassertion during slow 5V ramp-up. The 5V trip reenables when both rails exceed ~4.15V, allowing seamless dual-voltage operation without external logic.

Can the LTC1728HS5-5#TRPBF monitor a 1.8V supply instead of 5V?

No-the LTC1728HS5-5#TRPBF is specifically configured for 5V, 3.3V, and adjustable VCCA monitoring. For 1.8V/3.3V monitoring, use the LTC1728ES5-1.8#TRPBF or LTC1728ES5-3.3#TRPBF variants. The "-5" suffix denotes fixed 5V and 3.3V thresholds; substituting 1.8V on VCC5 pin violates specified operating conditions.

What is the minimum supply voltage required to guarantee correct RST logic state in the LTC1728HS5-5#TRPBF?

The LTC1728HS5-5#TRPBF guarantees correct RST logic state (low or high) for VCC5 or VCC3 ≥1V. Below 1V, RST behavior is undefined. This 1V minimum enables early reset assertion during power-down and compatibility with low-voltage brownout detection schemes.

Does the LTC1728HS5-5#TRPBF require external capacitors, and if so, where?

Yes-the LTC1728HS5-5#TRPBF requires ≥0.1µF ceramic bypass capacitors on both VCC3 (Pin 5) and VCC5 (Pin 4) pins, placed as close as possible to the device. These capacitors stabilize internal reference and comparator operation; omitting them risks erratic reset timing or false triggering during supply transients.