LTC6991 TimerBlox: Resettable, Low Frequency Oscillator FEATURESDESCRIPTION n Period Range: 1ms to 9.5 Hours The LTC®6991 is a silicon oscillator with a program- n Configured with 1 to 3 Resistors mable period range of 1.024ms to 9.54 hours (29.1µHz n <1.5% Maximum Frequency Error to 977Hz), specifically intended for long duration timing n Output Reset Function events. The LTC6991 is part of the TimerBlox® family of n 2.25V to 5.5V Single Supply Operation versatile silicon timing devices. n 55µA to 80µA Supply Current A single resistor, R n SET , programs the LTC6991’s inter- (2ms to 9.5hr Clock Period) nal master oscillator frequency. The output clock period n 500µs Start-Up Time is determined by this master oscillator and an internal n CMOS Output Driver Sources/Sinks 20mA frequency divider, N n DIV , programmable to eight settings –55°C to 125°C Operating Temperature Range from 1 to 221. n Available in Low Profile (1mm) SOT-23 (ThinSOT™) and 2mm × 3mm DFN Packages t NDIV •RSET n OUT = • 1.024ms, NDIV = 1,8,64,...,221 AEC-Q100 Qualified for Automotive Applications 50kΩ In normal operation, the LTC6991 oscillates with a 50% duty cycle. A reset function is provided to truncate the APPLICATIONS pulse (reducing the duty cycle). The reset pin can also be n “Heartbeat” Timers used to prevent the output from oscillating. n Watchdog Timers The RST and OUT pins can be configured for active-low n Intervalometers or active-high operation using a polarity function. n Periodic “Wake-Up” Call n POL BITRST PINOUTPUT STATE High Vibration, High Acceleration Environments n 0 0 Oscillating Portable and Battery-Powered Equipment 0 1 0 (reset) All registered trademarks and trademarks are the property of their respective owners. 1 0 1 (reset) 1 1 Oscillating For easy configuration of the LTC6991, use the LTC6991: Low Frequency Oscillator Web-Based Design Tool. TYPICAL APPLICATIONClock Period Range over Eight Divider Settings 10Hr Low Frequency Pulse Generator 1Hr 1µs PULSE WIDTH 10Min OUT R 60 SECONDS PW 1Min 2.26k 10Sec RST OUT CPW LTC6991 6991 TA01a 5V 1Sec 470pF GND V+ 100ms R R1 0.1µF CLOCK PERIOD (LOG SCALE) SET 715k 1M 10ms SET DIV R2 1ms 392k 0 0.625 1.25 1.875 2.5 tPULSE ≈ RPW • CPW ≈ 1µs DIV PIN VOLTAGE, VDIV (V) 6991 TA01b Rev. D Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
