Analog Devices Inc. LTC2956IMS-2#TRPBF

Overview

LTC2956IMS-2#TRPBF 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, supports adjustable wake-up periods from 250ms to 39 days via external resistors, and drives external P-channel MOSFETs directly for system power control in battery-powered intervalometers and portable data loggers.

For engineers reviewing the LTC2956IMS-2#TRPBF datasheet, LTC2956IMS-2#TRPBF pinout, LTC2956IMS-2#TRPBF application, or LTC2956IMS-2#TRPBF equivalent, key selection criteria include its –40°C to 85°C industrial temperature rating, MSOP-12 package, EN active-low output capability, configurable tLONG and tONMAX timing, ±25kV HBM ESD protection on PB input, and compatibility with high-voltage DC/DC enable sequencing.

Technical Context

The LTC2956IMS-2#TRPBF implements a dual-state finite-state machine (RUN and SHUTDOWN modes) with configurable digital period counter and analog/digital hybrid tONMAX timer. Its internal 2kHz oscillator feeds a programmable divider (÷1 to ÷222) to set tPERIOD, while tONMAX is controlled by an RC ramp on ONMAX pin (13.3ms/nF).

It features three status outputs (ONALERT, OFFALERT, PBOUT), debounced PB input with 32ms typical debounce time, and voltage-controlled mode transitions: SLEEP high > tLONG forces SHUTDOWN; PB low > tLONG initiates Shutting Off state with 1s OFFALERT pulse before full shutdown.

Key Specifications

Pinout & Package

12-Lead Plastic MSOP package (3.0mm × 4.9mm, 0.5mm pitch); exposed pad not connected in MSOP variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPL5010IPW and MAX16054ETA+, the LTC2956IMS-2#TRPBF uniquely supports both passive and active system architectures, provides three dedicated status outputs for deterministic state awareness, and enables field-configurable shutdown entry via tLONG - critical for shipped products with installed batteries.

Availability

LTC2956IMS-2#TRPBF is available at Aetrix Electronics and suitable for remote sensor nodes, portable medical loggers, industrial data acquisition systems, and intervalometer control requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LTC2956IMS-2#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, Inc. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, formed through the acquisition of Linear Technology in 2017.

The LTC2956IMS-2#TRPBF belongs to ADI's precision power management portfolio, designed specifically for ultra-low-power, battery-operated systems requiring deterministic, hardware-based wake-up control independent of host processor reliability.

FAQ

What is the EN output behavior of the LTC2956IMS-2#TRPBF during different operating states?

The LTC2956IMS-2#TRPBF EN pin is an active-low output. During AWAKE state, EN is pulled to GND to enable external P-MOSFET or active-low regulator. In SLEEP state, EN is pulled to VIN through a 900kΩ internal resistor. In SHUTDOWN mode, EN remains at VIN until the OFFALERT pulse ends, then goes high-impedance. This behavior is confirmed in the Pin Functions section and Block Diagram of the LTC2956IMS-2#TRPBF datasheet.

How does the LTC2956IMS-2#TRPBF enter SHUTDOWN mode, and what role does the LONG pin play?

The LTC2956IMS-2#TRPBF enters SHUTDOWN mode either by holding PB low longer than tLONG or by holding SLEEP high longer than tLONG. The LONG pin forms a resistor divider with RANGE to set tLONG between 128ms and 16.4s. If voltage at LONG exceeds VCC/2 at power-up, the device starts in RUN mode; if below VCC/2, it starts in SHUTDOWN mode - enabling configurable shipping-mode disable. This is detailed in the Power Up and Operation sections of the LTC2956IMS-2#TRPBF documentation.

Can the LTC2956IMS-2#TRPBF be used with a microcontroller that actively controls the SLEEP pin?

Yes, the LTC2956IMS-2#TRPBF fully supports active-system operation. The SLEEP pin can be toggled by a microcontroller to terminate the AWAKE state immediately after task completion, minimizing system-on time. The device ignores SLEEP transitions for tAWAKE_MIN (8ms typical) after EN assertion to ensure stability, and provides ONALERT/OFALERT pulses to signal state changes. This active control mode is explicitly described in the "Operations with SLEEP Toggling (Active System)" section of the LTC2956IMS-2#TRPBF datasheet.

What is the maximum allowable capacitor value on the ONMAX pin of the LTC2956IMS-2#TRPBF, and how does it affect timing?

The ONMAX pin of the LTC2956IMS-2#TRPBF supports capacitors up to 3.9nF, yielding a maximum tONMAX of 72ms (per Electrical Characteristics table). The relationship is linear at 13.3ms/nF. Larger capacitors beyond 3.9nF are not characterized and may cause timing inaccuracy or failure to meet specification. The ONMAX pin must not be left floating - it should be tied to GND if unused, or connected to a capacitor for precise awake-time control, as specified in the PIN FUNCTIONS section of the LTC2956IMS-2#TRPBF datasheet.

Does the LTC2956IMS-2#TRPBF require external components for basic operation, and which pins are mandatory?

Yes, the LTC2956IMS-2#TRPBF requires external components for full functionality: a resistor from PERIOD to GND (32.4kΩ–324kΩ) sets base tPERIOD; a resistor from RANGE to GND selects scaling; a resistor from LONG to GND configures tLONG; and a capacitor from ONMAX to GND sets tONMAX. Mandatory connections are VIN, GND, PB (with optional external switch), and EN (to load). Unused pins like OFFALERT, ONALERT, and PBOUT may be left open, as stated in the PIN FUNCTIONS section of the LTC2956IMS-2#TRPBF datasheet.