LTC1799 Datasheet

• One External Resistor Sets the Frequency
• Fast Start-Up Time: <1ms
• 1kHz to 33MHz Frequency Range
• Frequency Error ≤1.5% 5kHz to 20MHz (T_A = 25°C)
• Frequency Error ≤2% 5kHz to 20MHz (T_A = 0°C to 70°C)
• ±40ppm/°C Temperature Stability
• 0.05%/V Supply Stability
• 50% ±1% Duty Cycle 1kHz to 2MHz
• 50% ±5% Duty Cycle 2MHz to 20MHz
• 1mA Typical Supply Current
• 100Ω CMOS Output Driver
• Operates from a Single 2.7V to 5.5V Supply
• Low Profile (1mm) SOT-23 (ThinSOT^™ Package)
• AEC-Q100 Qualified for Automotive Applications

• Low Cost Precision Oscillator
• Switching Power Supply Clock Reference
• Clocking Switched Capacitor Filters
• Fixed Crystal Oscillator Replacement
• Ceramic Oscillator Replacement

The LTC1799 is a precision oscillator that is easy to use and occupies very little PC board space. The oscillator frequency is programmed by a single external resistor (R_SET). The LTC1799 has been designed for high accuracy operation (≤1.5% frequency error) without the need for external trim components.

The LTC1799 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. The frequency-setting resistor can vary from 3k to 1M to select a master oscillator frequency between 100kHz and 33MHz (5V supply). The three-state DIV input determines whether the master clock is divided by 1, 10 or 100 before driving the output, providing three frequency ranges spanning 1kHz to 33MHz (5V supply).

The LTC1799 features a proprietary feedback loop that linearizes the relationship between R_SET and frequency, eliminating the need for tables to calculate frequency.