LTC6990 Datasheet | Linear Technology

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 master oscillator to ensure clean, glitchfree output pulses. The...