Analog Devices Inc. LTC6991IS6#TRPBF

Overview

LTC6991IS6#TRPBF from Analog Devices is a silicon-based low-frequency oscillator IC designed for long-duration timing events, delivering programmable clock periods from 1.024 ms to 9.54 hours (29.1 µHz to 977 Hz) with ±1.5% max frequency accuracy, 55–80 µA supply current, and CMOS output capable of sourcing/sinking 20 mA. It serves as a precision "heartbeat" or wake-up timer in battery-powered industrial sensors.

For engineers reviewing the LTC6991IS6#TRPBF datasheet, LTC6991IS6#TRPBF pinout, LTC6991IS6#TRPBF application, or LTC6991IS6#TRPBF equivalent, key selection criteria include its single-resistor frequency programming (RSET), reset-triggered duty-cycle truncation, polarity-selectable RST/OUT behavior, and operation across –40°C to +85°C in the space-constrained SOT-23 package.

Technical Context

The LTC6991IS6#TRPBF integrates a master oscillator (1 MHz max, controlled by ISET = VSET/RSET) followed by a fixed ÷1024 divider and an 8-step programmable divider (NDIV = 1, 8, 64, ..., 2²¹), enabling precise period tuning via external resistors on SET and DIV pins. Its internal 4-bit A/D converter reads DIV pin voltage (VDIV) to set both NDIV and the POL bit.

Reset functionality operates independently of oscillation: when active (per POL configuration), RST forces OUT to a static high or low state without halting the internal master clock; propagation delay is 16–40 ns depending on supply voltage. Start-up time is 500 × tMASTER (≤8 ms typical), with power-on reset holding OUT low until initialization completes.

Key Specifications

Pinout & Package

Package: 6-lead TSOT-23 (S6), 1 mm profile, lead-free, RoHS-compliant. Exposed pad not present in S6 variant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-frequency oscillator applications.

Compared with MAX6375CSA+ and TPS3823DBVR, the LTC6991IS6#TRPBF uniquely combines user-programmable period (1 ms–9.5 hr), hardware reset-triggered pulse truncation, and ultra-low current draw - making it the sole option among the three for battery-operated interval timing and adaptive wake-up systems.

Availability

LTC6991IS6#TRPBF is available at Aetrix Electronics and suitable for industrial intervalometers, battery-powered wake-up timers, hardware watchdog circuits, and high-vibration system monitors requiring stable component supply across extended temperature ranges.

Supply support for LTC6991IS6#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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LTC6991IS6#TRPBF belongs to the TimerBlox® family - silicon timing devices engineered to replace crystals, RC networks, and microcontroller-based timers in applications demanding long-duration, low-drift, and programmable timing with minimal external components.

FAQ

What is the minimum and maximum output period supported by the LTC6991IS6#TRPBF?

The LTC6991IS6#TRPBF supports an output clock period range from 1.024 milliseconds to 34,360 seconds (9.54 hours), determined by the RSET resistor value and NDIV divider setting. This range is achieved using eight programmable divider ratios (1 to 2²¹) and a master oscillator tuned via a single external resistor on the SET pin. The LTC6991IS6#TRPBF achieves this without crystals or digital configuration interfaces.

How does the reset function work on the LTC6991IS6#TRPBF, and what is its timing behavior?

The RST pin on the LTC6991IS6#TRPBF provides hardware-controlled pulse truncation: when asserted (per polarity set by the DIV pin), it forces the OUT pin to a static logic level without halting the internal oscillator. Propagation delay is 16 ns at 5.5 V, 24 ns at 3.3 V, and 40 ns at 2.25 V. The LTC6991IS6#TRPBF continues internal timing during reset, enabling deterministic restart alignment. Reset does not affect frequency accuracy or long-term drift.

Can the LTC6991IS6#TRPBF operate from a 2.25 V supply, and how does supply voltage affect its performance?

Yes, the LTC6991IS6#TRPBF operates from 2.25 V to 5.5 V. Supply voltage impacts output drive strength (VOH/VOL shift with V+) and supply current (65–170 µA depending on RSET and V+), but frequency accuracy remains stable - frequency drift over supply is only ±0.06%/V at 2.25–4.5 V. The LTC6991IS6#TRPBF maintains full specification compliance across the entire supply range, including ±1.5% max frequency error and –40°C to +85°C operation.

What package type and footprint does the LTC6991IS6#TRPBF use, and are there thermal considerations?

The LTC6991IS6#TRPBF uses the 6-lead TSOT-23 (S6) package: 2.9 mm × 1.6 mm × 1.0 mm, with standard gull-wing leads. It has θJA = 192°C/W and requires no exposed pad connection. For thermal reliability, place a 0.1 µF ceramic capacitor between V+ and GND as close as possible to the device. Avoid routing noisy signals near the SET and DIV pins, and limit capacitance on those pins to <10 pF and <100 pF respectively. The LTC6991IS6#TRPBF is rated for TJMAX = 150°C.

Is the LTC6991IS6#TRPBF suitable for automotive applications, and what qualifications does it hold?

The LTC6991IS6#TRPBF is rated for –40°C to +85°C operation (I-grade) and is not AEC-Q100 qualified. However, Analog Devices offers automotive-grade variants (e.g., LTC6991IS6#WTRPBF) with controlled manufacturing and full AEC-Q100 qualification. The LTC6991IS6#TRPBF itself is intended for industrial and commercial applications. For automotive use, specify the #W suffix part; the LTC6991IS6#TRPBF should not be deployed in safety-critical vehicle systems without additional validation.