LTC6990 Datasheet | Linear Technology

Timer Blox: Voltage Controlled Silicon Oscillator Features n Fixed-Frequency or Voltage-Controlled Operation n Fixed: Single Resistor Programs Frequency with <1.5% Max Error n VCO: Two Resistors Set VCO Center Frequency and Tuning Range n Frequency Range: 488Hz to 2MHz n 2.25V to 5.5V Single Supply Operation n 72µA Supply Current at 100k Hz n 500µs Start-Up Time n VCO Bandwidth >300k Hz at 1MHz n CMOS Logic Output Sources/Sinks 20m A n 50% Duty Cycle Square Wave Output n Output Enable (Selectable Low or Hi-Z When Disabled) n 55°C to 125°C Operating Temperature Range n Available in Low Profile (1mm) SOT-23 (Thin SOT™) and 2mm × 3mm DFN Package n AEC-Q100 Qualified for Automotive Applications APPLICATIONS n Low Cost Precision Programmable Oscillator n Voltage-Controlled Oscillator n High Vibration, High Acceleration Environments n Replacement for Fixed Crystal and Ceramic Oscillators n Portable and Battery-Powered Equipment All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. patents, including 6342817, 6614313. DESCRIPTION The LTC®6990 is a precision silicon oscillator with a programmable frequency range of 488Hz to 2MHz. It can be used as a fixed-frequency or voltage-controlled oscillator (VCO). The LTC6990 is part of the Timer Blox® family of versatile silicon timing devices. A single resistor, RSET, programs the LTC6990’s internal master oscillator frequency. The output frequency is determined by this master oscillator and an internal frequency divider, NDIV, programmable to eight settings from 1 to 128. f OUT = 1MHz NDIV - 50kΩ RSET , NDIV = 1, 2, …128 Optionally, a second resistor at the SET input provides linear voltage control of the output frequency and can be used for frequency modulation. A narrow or wide VCO tuning range can be configured by the appropriate selection of the two resistors. The LTC6990 includes an enable function that is synchronized with the...