Overview
Features and Benefits
- Period Range: 1ms to 9.5 Hours
- Configured with 1 to 3 Resistors
- <1.5% Maximum Frequency Error
- Output Reset Function
- 2.25V to 5.5V Single Supply Operation
- 55μA to 80μA Supply Current (2ms to 9.5hr Clock Period)
- 500μs Start-Up Time
- CMOS Output Driver Sources/Sinks 20mA
- –55°C to 125°C Operating Temperature Range
- Available in Low Profile (1mm) SOT-23 (ThinSOT™) and 2mm × 3mm DFN Packages
Product Details
The LTC6991 is a silicon oscillator with a programmable period range of 1.024ms to 9.54 hours (29.1μHz to 977Hz), specifically intended for long duration timing events. The LTC6991 is part of the TimerBlox® family of versatile silicon timing devices.
A single resistor, RSET , programs the LTC6991’s internal master oscillator frequency. The output clock period is determined by this master oscillator and an internal frequency divider, NDIV , programmable to eight settings from 1 to 221.
In normal operation, the LTC6991 oscillates with a 50% duty cycle. A reset function is provided to truncate the pulse (reducing the duty cycle). The reset pin can also be used to prevent the output from oscillating.
The RST and OUT pins can be configured for active-low or active-high operation using a polarity function.
| POL Bit | RST Pin | Output State |
| 0 | 0 | Oscillating |
| 0 | 1 | 0 (reset) |
| 1 | 0 | 1 (reset) |
| 1 | 1 | Oscillating |
Applications
- “Heartbeat” Timers
- Watchdog Timers
- Intervalometers
- Periodic “Wake-Up” Call
- High Vibration, High Acceleration Environments
- Portable and Battery-Powered Equipment
Product Categories
Product Lifecycle
Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (1)
Documentation
Reliability Data (1)
Solutions Bulletins & Brochures (1)
Evaluation Kit Manuals (1)
Tools & Simulations
LTspice
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.
LTspice Simulations
Models for the following parts are available in LTspice:
Design Tools
Reference Materials
Product Selector Card (1)
Solutions Bulletins & Brochures (1)
Introducing the TimerBlox Family of Versatile, Easy To Use, Accurate Timing...
Technical Articles (1)
Design Resources
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Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
