Analog Devices LTC6905

Description

The LTC6905 precision, programmable silicon oscillator is easy to use and occupies very little board space. It requires only a single resistor to set the output frequency from 17MHz to 170MHz with a typical frequency error of 0.5% or less.

The LTC6905 operates with a single 2.7V to 5.5V power supply and provides a rail-to-rail, 50% duty cycle square wave output. The CMOS output driver ensures fast rise/fall times and rail-to-rail switching. Operation is simple: A single resistor, RSET, between 10K to 25K is used to set the frequency, and an internal three-state divider (DIV input) allows for division of the master clock by 1, 2 or 4, providing three frequencies for each RSET value.

The LTC6905 features a proprietary feedback loop that linearizes the relationship between RSET and frequency, eliminating the need for tables to calculate frequency. The oscillator can be easily programmed using the simple formula outlined below:

See first page of Data Sheet for formula

For higher accuracy, fixed frequency versions that includean internal frequency-setting resistor, see the LTC6905-XXX Series datasheet.

Features

• One External Resistor Sets the Frequency
• Fast Start-Up Time: 100µs Typical
• Frequency Range: 17MHz to 170MHz
• Frequency Error ±0.5% Typ 17MHz to 170MHz
• (TA = 0°C to 70°C, Over All Settings)
• ±20ppm/°C Temperature Stability
• Rise Time: 0.5ns, CL = 5pF
• Timing Jitter: 7.2ps RMS at 170MHz
• 50% ±2.5% Duty Cycle
• 6mA Typical Supply Current, fOSC = 100MHz
• CMOS Output Drives 500Ω Load (VS = 3V)
• Operates from a Single 2.7V to 5.5V Supply
• Low Profile (1mm) ThinSOT Package

Typical applications

• High Frequency Precision Oscillator
• Fixed Crystal Oscillator Replacement
• High Speed Data Bus Clock
• Ceramic Oscillator Replacement

More information

• Datasheet
• IC product information