LTC1799CS5#TRPBF Clock Timer ICS RS-232 Interface IC 1x 5V RS232/RS485 Multiprotocol Tran

LTC1799CS5#TRPBF Clock Timer ICS RS-232 Interface IC 1x 5V RS232/RS485 Multiprotocol Tran

FeaTures

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

ApplicaTions

n Low Cost Precision Oscillator
n Charge Pump Driver
n Switching Power Supply Clock Reference
n Clocking Switched Capacitor Filters
n Fixed Crystal Oscillator Replacement
n Small Footprint Replacement for Econ Oscillators

DescripTion

The LTC®1799 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 (RSET). 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 oscil- lator 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 out- put, providing three frequency ranges spanning 1kHz to 33MHz (5V supply). The LTC1799 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: