Datasheet LTC6990 (Analog Devices)

LTC6990 TimerBlox: Voltage Controlled Silicon Oscillator
FEATURES DESCRIPTION
n
Fixed-Frequency or Voltage-Controlled Operation
The LTC®6990 is a precision silicon oscillator with a pro- n
Fixed: Single Resistor Programs Frequency with
grammable frequency range of 488Hz to 2MHz. It can be
<1.5% Max Error
used as a fixed-frequency or voltage-controlled oscillator n
VCO: Two Resistors Set VCO Center Frequency
(VCO). The LTC6990 is part of the TimerBlox® family of
and Tuning Range
versatile silicon timing devices. n
Frequency Range: 488Hz to 2MHz
A single resistor, RSET, programs the LTC6990’s inter- n 2.25V to 5.5V Single Supply Operation nal master oscillator frequency. The output frequency n 72µA Supply Current at 100kHz is determined by this master oscillator and an internal n 500µs Start-Up Time frequency divider, NDIV, programmable to eight settings n VCO Bandwidth >300kHz at 1MHz from 1 to 128. n CMOS Logic Output Sources/Sinks 20mA n 50% Duty Cycle Square Wave Output 1MHz 50kΩ f • , N n Output Enable (Selectable Low or Hi-Z When Disabled) OUT = DIV = 1, 2, 4 …128 NDIV RSET n 55°C to 125°C Operating Temperature Range n Optional y, a second resistor at the SET input provides Available in Low Profile (1mm) SOT-23 (ThinSOT™) linear voltage control of the output frequency and can be and 2mm × 3mm DFN Package n used for frequency modulation. A narrow or wide VCO AEC-Q100 Qualified for Automotive Applications tuning range can be configured by the appropriate selec- tion of the two resistors.
APPLICATIONS
The LTC6990 includes an enable function that is synchro- n Low Cost Precision Programmable Oscillator nized with the master oscillator to ensure clean, glitch- n Voltage-Controlled Oscillator free output pulses. The disabled output can be configured n High Vibration, High Acceleration Environments to be high impedance or forced low. n Replacement for Fixed Crystal and Ceramic Oscillators n Portable and Battery-Powered Equipment For easy configuration of the LTC6990, use the TimerBlox LTC6990: Voltage Control ed Oscil ator Web-Based All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. patents, including 6342817, 6614313. Design Tool.
TYPICAL APPLICATION Voltage Controlled Oscillator with 16:1 Frequency Range VCO Transfer Function
1000 MHz V+ fOUT = 2MHz − VCTRL • V 750 OE OUT LTC6990 V+ (kHz) 500 GND V+ f OUT C1 RVCO 0.1µF 100k 250 VCTRL SET DIV R 6990 TA01a SET 100k 0 0 0.5 1 1.5 2 VCTRL (V) 6990 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