Analog Devices Inc. LTC1326IMS8-2.5#TRPBF

Overview

LTC1326IMS8-2.5#TRPBF from Analog Devices (formerly Linear Technology) is a micropower precision triple supply monitor IC designed for systems requiring simultaneous supervision of 2.5V, 3.3V, and an adjustable voltage rail. It delivers ±0.75% threshold accuracy, 20µA typical supply current, and guaranteed reset assertion down to VCC3 ≥ 1V or VCC25 ≥ 1V - enabling reliable power-on reset in portable battery-powered equipment and notebook computers.

For engineers reviewing the LTC1326IMS8-2.5#TRPBF datasheet, LTC1326IMS8-2.5#TRPBF pinout, LTC1326IMS8-2.5#TRPBF application, or LTC1326IMS8-2.5#TRPBF equivalent, key selection considerations include its dual-mode push-button reset (100µs soft pulse / 200ms hard reset), open-drain RST/SRST outputs with weak internal pull-ups to VCC3, and guaranteed glitch immunity across all monitored rails.

Technical Context

The LTC1326IMS8-2.5#TRPBF integrates three precision voltage comparators with 13µs typical response time and built-in 25mV hysteresis to suppress transients on VCC25, VCC3, and VCCA inputs. Its internal reset generator enforces a fixed 200ms delay after all supplies exceed their thresholds before releasing RST.

Power detection logic selects gate drive for the RST output FET from either VCC3 or VCC25 (not VCC5), ensuring valid low-level reset assertion even when VCC3 drops to 1V. The PBR input features a 7µA internal pull-up and 20ms debounce, enabling robust manual reset initiation without external components.

Key Specifications

Pinout & Package

Package: 8-lead MSOP (MS8), 3.0mm × 3.0mm × 0.86mm body, 0.65mm pitch, RoHS-compliant lead-free finish (#TRPBF).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC1726-2.5 and LTC1727-2.5, the LTC1326IMS8-2.5#TRPBF delivers superior threshold accuracy (±0.75% vs. ±1.5%) and lowest quiescent current (20µA vs. 35µA/25µA), making it ideal for precision-critical, ultra-low-power applications where consolidated reset signaling suffices.

Availability

LTC1326IMS8-2.5#TRPBF is available at Aetrix Electronics and suitable for desktop computers, notebook computers, and intelligent instruments requiring stable component supply with guaranteed long-term manufacturability and consistent parametric performance.

Supply support for LTC1326IMS8-2.5#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 acquired Linear Technology in 2017 and maintains full product support, datasheet archives, and application engineering resources for legacy Linear parts.

The LTC1326 family was designed specifically for micropower, high-accuracy triple-supply monitoring in space- and power-constrained computing platforms - emphasizing guaranteed reset validity down to 1V and robust push-button interface integration.

FAQ

What is the primary function of the LTC1326IMS8-2.5#TRPBF?

The LTC1326IMS8-2.5#TRPBF is a micropower triple supply monitor IC that simultaneously supervises 2.5V (VCC25), 3.3V (VCC3), and an adjustable rail (VCCA) with ±0.75% threshold accuracy. It generates a 200ms active-low reset pulse on RST when any monitored supply falls below its trip point, and supports manual reset via the PBR pin with both soft (100µs SRST) and hard (200ms RST) modes. The LTC1326IMS8-2.5#TRPBF guarantees valid reset assertion down to VCC3 ≥ 1V or VCC25 ≥ 1V.

How does the LTC1326IMS8-2.5#TRPBF handle power-up sequencing?

During power-up, the LTC1326IMS8-2.5#TRPBF asserts RST low until all three monitored supplies (VCC25, VCC3, VCCA) remain above their respective thresholds for a continuous 200ms period. The internal timer starts only after all rails stabilize, ensuring clean release of reset. The LTC1326IMS8-2.5#TRPBF uses VCC25 or VCC3 to drive the RST output FET, guaranteeing low-level assertion even when one supply reaches only 1V - critical for reliable cold-start behavior.

Can the LTC1326IMS8-2.5#TRPBF monitor fewer than three supplies?

Yes, the LTC1326IMS8-2.5#TRPBF supports dual- and single-supply configurations via pin-strapping overrides. VCCA can be tied to VCC3 or VCC25 to disable its comparator. VCC25 may be tied to VCC3 if only 3.3V monitoring is needed. The LTC1326IMS8-2.5#TRPBF retains full functionality including PBR-initiated soft/hard reset and 200ms timing regardless of active rail count - enabling flexible reuse across product variants.

What are the electrical characteristics of the RST and SRST outputs?

Both RST (Pin 6) and SRST (Pin 7) are open-drain outputs with 6µA weak internal pull-ups to VCC3. They sink up to 5mA with VOL ≤ 0.4V and support external pull-up voltages exceeding VCC3 (e.g., to 5V logic). RST is complemented by active-high RST (Pin 5), which drives to VCC3. The LTC1326IMS8-2.5#TRPBF specifies tPHL = 25ns and tPLH = 45ns propagation delays into 20pF load - enabling fast reset deassertion in high-speed digital systems.

Is the LTC1326IMS8-2.5#TRPBF compatible with modern PCB assembly processes?

Yes, the LTC1326IMS8-2.5#TRPBF is supplied in an 8-lead MSOP (MS8) package with RoHS-compliant lead-free finish (#TRPBF suffix) and standard reflow profiles. Its 0.65mm pitch, 3.0mm × 3.0mm footprint, and exposed pad-free construction are fully compatible with automated SMT placement and lead-free reflow soldering. The recommended solder pad layout is documented in Linear Technology drawing #05-08-1660, ensuring reliable thermal and mechanical attachment in high-volume manufacturing.