Datasheet LTC1799 (Analog Devices)

LTC1799 1kHz to 33MHz Resistor Set SOT-23 Oscillator
FeaTures DescripTion
n
One External Resistor Sets the Frequency
The LTC®1799 is a precision oscillator that is easy to use n
Fast Start-Up Time: <1ms
and occupies very little PC board space. The oscillator n
1kHz to 33MHz Frequency Range
frequency is programmed by a single external resistor n Frequency Error ≤1.5% 5kHz to 20MHz (RSET). The LTC1799 has been designed for high accuracy (TA = 25°C) operation (≤1.5% frequency error) without the need for n Frequency Error ≤2% 5kHz to 20MHz external trim components. (TA = 0°C to 70°C) The LTC1799 operates with a single 2.7V to 5.5V power n ±40ppm/°C Temperature Stability supply and provides a rail-to-rail, 50% duty cycle square n 0.05%/V Supply Stability wave output. The CMOS output driver ensures fast rise/ n 50% ±1% Duty Cycle 1kHz to 2MHz fall times and rail-to-rail switching. The frequency-setting n 50% ±5% Duty Cycle 2MHz to 20MHz resistor can vary from 3k to 1M to select a master oscil- n 1mA Typical Supply Current lator frequency between 100kHz and 33MHz (5V supply). n 100Ω CMOS Output Driver The three-state DIV input determines whether the master n Operates from a Single 2.7V to 5.5V Supply clock is divided by 1, 10 or 100 before driving the out- n Low Profile (1mm) SOT-23 (ThinSOT™ Package) put, providing three frequency ranges spanning 1kHz to 33MHz (5V supply). The LTC1799 features a proprietary
applicaTions
feedback loop that linearizes the relationship between RSET n Low Cost Precision Oscillator and frequency, eliminating the need for tables to calculate n Charge Pump Driver frequency. The oscillator can be easily programmed using n Switching Power Supply Clock Reference the simple formula outlined below: n Clocking Switched Capacitor Filters n ⎧ Fixed Crystal Oscillator Replacement 100, DIV Pin = V+ ⎛ ⎞ ⎪ n Ceramic Oscillator Replacement fOSC = 10MHz • 10k ⎜ ⎟, N = ⎨10, DIV Pin = Open n Small Footprint Replacement for Econ Oscillators ⎝N • RSET ⎠ ⎪1, DIVPin=GND L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and ⎩ ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 6342817 and 6614313.
Typical applicaTion Typical Distribution of Frequency Error, TA = 25°C (5kHz ≤ fOSC ≤ 20MHz, V+ = 5V)
25
Basic Connection
1kHz ≤ f 20 OSC ≤ 33MHz 5V 1 5 V+ OUT 0.1µF LTC1799 15 2 5V 3k ≤ RSET ≤ 1M GND ÷100 3 4 ÷10 UNITS (%) 10 SET DIV OPEN ÷1 1799 TA01 5
TSOT-23 Actual Size
0–1.25 –0.75 –0.25 0 0.25 0.75 1.25 FREQUENCY ERROR (%) 1799 TA02 1799fd For more information www.linear.com/LTC1799 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Theory of Operation Applications Information Typical Application Package Description Revision History Typical Applications