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
- AEC-Q100 Qualified for Automotive Applications
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)
User Guides (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 Designs (1)
Reference Materials
Product Selector Card (1)
Solutions Bulletins & Brochures (1)
Introducing the TimerBlox Family of Versatile, Easy To Use, Accurate Timing...
Technical Articles (2)
Design Resources
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PCN-PDN Information
Support & Discussions
LTC6991 Discussions
Sample & Buy
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