Analog Devices Inc. LTC2918HMS-A1#PBF

Overview

LTC2918HMS-A1#PBF from Analog Devices (formerly Linear Technology) is a high-temperature voltage supervisor IC with manual reset input, 9 selectable supply thresholds (12V to ADJ), fixed –5% tolerance, and adjustable watchdog/reset timers. It operates from 1.5V to 5.5V, consumes 30μA typical quiescent current, guarantees ±1.5% threshold accuracy over –40°C to 125°C, and delivers reliable reset assertion for automotive control systems and industrial embedded power monitoring.

For engineers reviewing the LTC2918HMS-A1#PBF datasheet, LTC2918HMS-A1#PBF pinout, LTC2918HMS-A1#PBF application, or LTC2918HMS-A1#PBF equivalent, key selection criteria include its MSOP-10 package, –40°C to 125°C operating range, internal 200ms reset timeout (RT = VCC), 1.6s watchdog upper boundary (WT = VCC), manual reset (MR) interface, and guaranteed RST assertion down to VCC ≥ 0.8V.

Technical Context

The LTC2918HMS-A1#PBF implements a dual-timer architecture: an internal 200ms reset timeout when RT is tied to VCC, and a 1.6s windowed watchdog upper boundary when WT is tied to VCC - though the A1 variant uses standard (non-windowed) watchdog timing. Its VM input compares against one of nine factory-programmed thresholds selected via SEL1/SEL2 three-state logic, with fixed –5% tolerance and ±1.5% accuracy across temperature.

It features an open-drain RST output with guaranteed low-voltage operation (RST asserted at VCC ≥ 0.8V), internal 100kΩ MR pull-up enabling push-button reset without external components, and glitch immunity via combined timer-based filtering and comparator-level anti-glitch circuitry (tUV ≤ 150μs). The device includes a 6.2V shunt regulator on VCC for high-voltage supply compatibility.

Key Specifications

Pinout & Package

Package: 10-Lead MSOP (3mm × 3mm), RoHS-compliant, lead-free finish. Thermal resistance θJA = 200°C/W. Exposed pad optional for thermal enhancement.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervisor applications.

Compared with MAX6326US29D3+T and TPS3808G18DBVR, the LTC2918HMS-A1#PBF provides unique value through its 9-threshold flexibility, integrated MR pin, 125°C rating, and dual-timer architecture - making it irreplaceable in automotive and industrial systems requiring robust, configurable power supervision.

Availability

LTC2918HMS-A1#PBF is available at Aetrix Electronics and suitable for automotive engine control units, industrial PLCs, telecom base station power sequencing, and medical diagnostic imaging subsystems requiring stable component supply across extended temperature ranges.

Supply support for LTC2918HMS-A1#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 leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LTC2918 belongs to ADI's precision voltage supervisor product line, designed specifically for mission-critical power monitoring in harsh environments where reliability, accuracy, and extended temperature operation are mandatory.

FAQ

What is the maximum supply voltage the LTC2918HMS-A1#PBF can tolerate on its VCC pin?

The LTC2918HMS-A1#PBF has an absolute maximum VCC rating of 5.7V for direct connection. However, it integrates a 6.2V shunt regulator, allowing operation from higher supplies (e.g., 12V) when a current-limiting series resistor is used to keep VCC pin current ≤5mA. Without that resistor, exceeding 5.7V risks violating terminal current limits.

Does the LTC2918HMS-A1#PBF support windowed watchdog functionality?

No, the LTC2918HMS-A1#PBF does not support windowed watchdog functionality. It is the "A1" variant, which implements standard watchdog timing (only upper boundary enforcement). Windowed watchdog - requiring both upper and lower timing boundaries - is exclusive to "B1" variants like LTC2918HMS-B1#PBF.

How is the reset timeout configured on the LTC2918HMS-A1#PBF?

The LTC2918HMS-A1#PBF offers three reset timeout configurations: (1) RT left open → ~400μs; (2) RT tied to VCC → fixed 200ms internal timeout; (3) RT connected to GND via capacitor CRT → adjustable timeout per CRT = tRST × 110 pF/ms. For example, 2.2nF yields ~20ms.

Can the LTC2918HMS-A1#PBF monitor a 1.2V supply, and what is its accuracy at that level?

Yes, the LTC2918HMS-A1#PBF supports 1.2V monitoring via SEL1=GND/SEL2=VCC configuration. At 1.2V nominal, the guaranteed trip threshold is 1.2V × 0.95 = 1.14V, with ±1.5% accuracy meaning actual trip occurs between 1.122V and 1.158V over –40°C to 125°C - fully meeting industrial 1.2V rail supervision needs.

Is an external pull-up resistor required for the RST output of the LTC2918HMS-A1#PBF?

Yes, the RST pin is open-drain and requires an external pull-up resistor to the target logic supply (e.g., 3.3V or 5V). Typical values range from 4.7kΩ to 10kΩ. The LTC2918HMS-A1#PBF does not provide internal pull-up on RST - this must be implemented externally to ensure proper logic-high state during normal operation.