Analog Devices Inc. LTC2951CDDB-2#TRPBF

Overview

LTC2951CDDB-2#TRPBF from Analog Devices (formerly Linear Technology) is a micropower pushbutton ON/OFF controller with low-true enable output, operating from 2.7V to 26.4V supply, consuming 6µA typical quiescent current, featuring 128ms fixed turn-on debounce, and designed for circuit breaker control in battery-powered portable instrumentation and blade servers.

For engineers reviewing the LTC2951CDDB-2#TRPBF datasheet, LTC2951CDDB-2#TRPBF pinout, LTC2951CDDB-2#TRPBF application, or LTC2951CDDB-2#TRPBF equivalent, key selection factors include EN polarity (low-true), KILL input threshold (0.6V), adjustable KILL turn-off delay via KILLT capacitor, and DFN-8 (3mm × 2mm) package compatibility with space-constrained embedded power management.

Technical Context

The LTC2951CDDB-2#TRPBF implements a state-machine-based pushbutton interface with dual-stage timing: fixed 128ms turn-on debounce and programmable turn-off sequence initiated by PB hold ≥32ms plus optional OFFT capacitor extension. Its KILL input enables µP-coordinated shutdown or autonomous fault-triggered power-down via 0.6V comparator with 50mV hysteresis.

Internally, the device uses an oscillator-driven debounce logic block, open-drain INT interrupt output for µP handshaking, and separate KILLT/OFFT pins accepting external capacitors to extend timeout periods beyond internal defaults (128ms KILL off-delay, 32ms turn-off debounce). The EN output is actively pulled low on assertion, compatible with circuit breaker gate control.

Key Specifications

Pinout & Package

Package: 8-lead plastic DFN (3mm × 2mm), exposed pad (optional GND connection), RoHS-compliant, moisture-sensitive level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar pushbutton power control applications.

Compared with TPS3808G33DBVR and MAX6816EUT+T, the LTC2951CDDB-2#TRPBF integrates complete hardware-managed power sequencing-including low-true EN, µP handshake, and field-programmable timeouts-in a single 3mm × 2mm DFN, reducing BOM count and layout complexity for battery-powered embedded systems.

Availability

LTC2951CDDB-2#TRPBF is available at Aetrix Electronics and suitable for portable instrumentation meters, blade servers, and desktop/notebook computers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for LTC2951CDDB-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 acquired Linear Technology in 2017 and maintains its precision analog and power management product lines with full datasheet, simulation model, and application support.

The LTC2951 family was designed specifically for robust, low-power pushbutton-initiated power sequencing in portable and industrial equipment, emphasizing hardware autonomy, wide voltage operation, and ESD-hardened interfaces.

FAQ

What is the EN output behavior of the LTC2951CDDB-2#TRPBF?

The LTC2951CDDB-2#TRPBF features a low-true open-drain EN output. It asserts low to enable system power (e.g., turning on a circuit breaker or PFET) after a valid 128ms PB press, and releases high during shutdown sequences triggered by PB hold, KILL low, or KILL timeout. The output operates from 0V to 10V and requires an external pull-up for high-state definition.

How does the KILL input function in the LTC2951CDDB-2#TRPBF?

The KILL input of the LTC2951CDDB-2#TRPBF is a 0.6V threshold comparator that forces EN release when pulled low. During normal operation, it confirms µP readiness after power-on (within 512ms blanking window) or initiates immediate shutdown. In fault mode, if KILL remains high past the KILL turn-off delay, EN releases autonomously-ensuring fail-safe power-down even if the µP hangs.

Can the LTC2951CDDB-2#TRPBF operate from a single-cell Li-ion battery?

Yes, the LTC2951CDDB-2#TRPBF operates from 2.7V to 26.4V, fully covering the discharge range of a single-cell Li-ion battery (4.2V down to ~2.8V). Its 6µA quiescent current minimizes drain during standby, and the 0.6V KILL threshold allows precise end-of-discharge detection using a resistor divider, making the LTC2951CDDB-2#TRPBF ideal for portable battery-powered devices.

What is the purpose of the KILLT and OFFT pins on the LTC2951CDDB-2#TRPBF?

The KILLT pin adds adjustable delay to the KILL-initiated power-off timeout beyond the internal 128ms default; the OFFT pin extends the PB hold time required to initiate shutdown beyond the internal 32ms debounce. Both accept external capacitors (e.g., 33nF yields ~11.5ms additional delay each), enabling field-tunable timing without firmware changes-critical for meeting safety or usability requirements across product variants.

Is the LTC2951CDDB-2#TRPBF pin-compatible with the LTC2951CDDB-1#TRPBF?

No-the LTC2951CDDB-2#TRPBF and LTC2951CDDB-1#TRPBF share identical pinout and package but differ in EN output polarity: LTC2951CDDB-2#TRPBF asserts EN low to enable power (low-true), while LTC2951CDDB-1#TRPBF asserts EN high (high-true). Swapping them requires corresponding changes to the driven circuit (e.g., PFET vs NFET gate drive, active-low vs active-high enable input).