Analog Devices Inc. LTC2956CMS-2#PBF

Overview

LTC2956CMS-2#PBF from Analog Devices (formerly Linear Technology) is a micropower, wide-input wake-up timer IC with pushbutton control and active-low enable output. It operates from 1.5V to 36V, delivers 0.8µA quiescent current in awake state and 0.3µA in shutdown, and supports configurable wake-up periods from 250ms to 39 days-enabling periodic sensor monitoring in battery-powered remote telemetry nodes.

For engineers reviewing the LTC2956CMS-2#PBF datasheet, LTC2956CMS-2#PBF pinout, LTC2956CMS-2#PBF application, or LTC2956CMS-2#PBF equivalent, key selection criteria include its high-voltage EN output for direct P-channel MOSFET drive, ±25kV HBM ESD tolerance on PB input, MSOP-12 package compatibility, and dual-mode operation (RUN/SHUTDOWN) controlled via LONG pin resistor divider.

Technical Context

The LTC2956CMS-2#PBF implements a digitally programmable wake-up timer with analog timing elements: a 2kHz oscillator drives a programmable divider (÷1 to ÷2²²) for period setting, while ONMAX uses an analog ramp + digital counter for maximum awake time control. Its logic interprets SLEEP transitions and PB debounced edges to manage state transitions between AWAKE, SLEEP, and SHUTDOWN modes.

Unlike the LTC2956-1 variant, the LTC2956CMS-2#PBF features an active-low EN output capable of sinking current to GND or pulling up to VIN (via internal 900kΩ resistor), enabling direct gate drive of external P-channel MOSFETs without level-shifting. The device performs configuration reads at RANGE and LONG pins once every 66 seconds during RUN mode, minimizing bias current draw.

Key Specifications

Pinout & Package

12-Lead Plastic MSOP package (3.0mm × 4.0mm, 0.65mm pitch), thermally enhanced with exposed pad (GND-connected). Pin 1 marked by dot; pin numbering follows standard MSOP convention.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar wake-up timer applications.

Compared with TPS3897A30DBVR and MAX16054ASA+, the LTC2956CMS-2#PBF uniquely combines 36V operation, sub-µA quiescent current, hardware-configurable multi-day intervals, and dual alert outputs-making it the sole option for robust, maintenance-free, long-duration battery systems requiring deterministic power sequencing.

Availability

LTC2956CMS-2#PBF is available at Aetrix Electronics and suitable for remote sensor nodes, industrial data loggers, smart meter modules, and portable medical diagnostics requiring stable component supply across extended product lifecycles.

Supply support for LTC2956CMS-2#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 acquired Linear Technology in 2017 and maintains full technical and manufacturing continuity for the LTC portfolio. Linear pioneered precision analog and power management ICs for demanding industrial and instrumentation applications.

The LTC2956CMS-2#PBF belongs to Linear's micropower system supervision family, designed specifically for energy-constrained applications requiring autonomous, reliable, and configurable power cycling without MCU intervention.

FAQ

What is the key functional difference between LTC2956CMS-2#PBF and LTC2956CMS-1#PBF?

The LTC2956CMS-2#PBF features an active-low EN output that pulls to GND when enabled and to VIN (via internal 900kΩ resistor) when disabled-optimized for driving P-channel MOSFET gates directly. In contrast, the LTC2956CMS-1#PBF provides an active-high EN output pulled to a 3.3V internal regulator, intended for controlling enable inputs of DC/DC converters. Both share identical timing, debounce, and alert functionality.

Can LTC2956CMS-2#PBF operate from a 1.8V supply?

Yes, the LTC2956CMS-2#PBF supports supply voltages as low as 1.5V. At 1.8V, all specifications-including 0.8µA quiescent current, 250ms minimum wake-up period, and ±25kV PB ESD rating-remain valid across the full operating temperature range (0°C to 70°C for the CMS grade). UVLO activates at 1.24V with 100mV hysteresis.

How does the LONG pin resistor network determine power-up behavior for LTC2956CMS-2#PBF?

The LONG pin voltage relative to VIN/2 sets initial mode: if VLONG > VIN/2 (e.g., 100kΩ from LONG to VIN, 9.76kΩ from LONG to GND), LTC2956CMS-2#PBF enters RUN mode at power-up. If VLONG < VIN/2 (e.g., open LONG or 100kΩ to GND), it starts in SHUTDOWN mode-requiring a PB press to initiate operation. This enables ship-with-battery functionality.

Does LTC2956CMS-2#PBF require external components to achieve its specified 250ms–39 day wake-up period?

Yes, the LTC2956CMS-2#PBF requires two external resistors (PERIOD and RANGE) and optionally a third (LONG) to configure timing. A 100kΩ PERIOD resistor yields 250ms base period; RANGE selects scaling factor (×1, ×4, ×16, etc.); combined, they cover 250ms to 39 days. No capacitors are needed for period setting-only for ONMAX-based awake-time limiting.

What happens to the EN output of LTC2956CMS-2#PBF during the 1-second OFFALERT pulse?

During the OFFALERT pulse (tOFF ≈ 1s), the LTC2956CMS-2#PBF is in the "Shutting Off" state: EN remains high (driven to VIN) to keep the system powered while OFFALERT signals the pending shutdown. Only after tOFF completes does EN pull low (to GND), transitioning the device to the Off state and reducing quiescent current to 0.3µA.