Analog Devices Inc. LTC2956IMS-2#PBF

Overview

LTC2956IMS-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, supports adjustable wake-up periods from 250ms to 39 days via external resistors, and drives external P-channel MOSFETs for high-voltage system power control in battery-powered remote sensors.

For engineers reviewing the LTC2956IMS-2#PBF datasheet, LTC2956IMS-2#PBF pinout, LTC2956IMS-2#PBF application, or LTC2956IMS-2#PBF equivalent, key selection criteria include its negative-enable polarity, MSOP-12 package compatibility, ±25kV HBM ESD rating on PB input, and precise tLONG/tONMAX timing configuration via external R/C networks.

Technical Context

The LTC2956IMS-2#PBF implements a dual-state finite-state machine (Awake/Sleep) with configurable transition timers (tPERIOD, tONMAX, tSLEEP_MIN, tLONG) and a dedicated shutdown path triggered by long PB or SLEEP pulses. Its internal 2kHz oscillator feeds a programmable digital divider (÷1 to ÷222) for period generation, while tONMAX uses analog ramp + digital counter hybrid timing.

It features three open-drain status outputs (ONALERT, OFFALERT, PBOUT), debounced PB input with 32ms typical debounce time, and an active-low EN output capable of sinking up to 1mA while pulling to VIN – 1.5V (typical) - enabling direct gate drive of high-side P-MOSFETs without level-shifting circuitry.

Key Specifications

Pinout & Package

12-Lead Plastic MSOP package (3mm × 4.9mm), exposed pad not connected (no thermal requirement). Pin 1 marked; 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 LTC2956IMS-2#PBF uniquely integrates programmable periodic wake-up, pushbutton-initiated control, and three status outputs - enabling true autonomous low-power system management without MCU involvement.

Availability

LTC2956IMS-2#PBF is available at Aetrix Electronics and suitable for remote environmental sensing, industrial data logging, and portable medical monitoring requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for LTC2956IMS-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, Inc. (ADI) is a global semiconductor leader specializing in high-performance analog, mixed-signal, and digital signal processing technologies.

The LTC2956IMS-2#PBF belongs to ADI's precision power management portfolio, designed specifically for ultra-low-power, battery-operated systems requiring autonomous periodic wake-up, robust pushbutton interface, and industrial-grade reliability.

FAQ

What is the EN output behavior of the LTC2956IMS-2#PBF?

The LTC2956IMS-2#PBF features an active-low EN output (LTC2956-2 variant) that pulls to GND when the system is awake and to VIN when asleep. It can sink 1mA and is rated for VIN – 1.5V (typical) high-level output - enabling direct drive of P-channel MOSFET gates without external level shifters. This behavior is confirmed in the Pin Functions section and Electrical Characteristics table under VEN(VOH) for LTC2956-2.

How does the LTC2956IMS-2#PBF enter SHUTDOWN mode?

The LTC2956IMS-2#PBF enters SHUTDOWN mode either by holding the PB pin low longer than tLONG (configurable 128ms–16.4s) or by holding the SLEEP pin high longer than tLONG. Upon entry, it transitions through a 1-second Shutting Off state (OFFALERT low), then reaches the Off state with EN pulled low and quiescent current reduced to 0.3µA. This is detailed in the Operation section and Figure 7/Figure 8 of the datasheet.

Can the LTC2956IMS-2#PBF operate from a 1.8V supply?

Yes, the LTC2956IMS-2#PBF operates from 1.5V to 36V, so 1.8V is within specification. Its undervoltage lockout (UVLO) activates below 1.24V (typical) with 100mV hysteresis, ensuring reliable startup and brownout protection. The 0.8µA quiescent current remains valid across this range, as confirmed in the Electrical Characteristics table under VIN Supply Current.

What is the purpose of the ONALERT and OFFALERT pins on the LTC2956IMS-2#PBF?

ONALERT pulls low at the start of each RUN mode (e.g., after power-up or PB short press) to signal the MCU to execute initialization routines. OFFALERT pulls low for 1 second during the transition from RUN to SHUTDOWN mode, providing advance warning for graceful shutdown. Both are open-drain outputs requiring external pull-ups, as specified in the Pin Functions section and Timing Diagram.

How is the wake-up period configured on the LTC2956IMS-2#PBF?

The wake-up period (tPERIOD) is set using two external resistors: one from PERIOD to GND (32.4kΩ–324kΩ) establishes the base period (237–263ms), and another from RANGE to GND (with 100kΩ to LONG) selects the scaling factor (×1, ×4, ..., ×222), extending the range to 250ms–39 days. Configuration occurs every 66 seconds in RUN mode and after power-up or SHUTDOWN exit.