LTC6945

28

6945fa



LINEAR TECHNOLOGY CORPORATION 2011

LT 0315 REV A • PRINTED IN USA

LinearTechnology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

relaTeD parTs

Typical applicaTion

LTC6945 Wideband Point-to-Point Radio Local Oscillator

GND

GND

GND

GND

GND

REFO

STAT

CS

SCLK

SDI

SDO

GND

LTC6945

O_DIV = 2

3.3V

0.1µF

100MHz

REF

0.01µF

100pF

1.0µF

18.3nF

LT1678IS8

113

4.99k

51.1

4.99k

230nF

1µF

1µF

0.1µF

0.1µF

47µF

3.3V

3.3V

SPI BUS

0.1µF

0.01µF

68nH

68nH

3.3V

3.3V

LO OUT

4900MHz TO 5900MHz

IN STEPS OF 5MHz

3.3V

100pF

50

100pF

4.7nF

5V RFMD

UMZ-T2-227-O16-G

100pF

6945 TA03a

5V

0.1µF

0.1µF

LOOP BANDWIDTH = ~21.4kHz

11V

5V

3.3V

100

+

–

Radio Local Oscillator

OFFSET FREQUENCY (Hz)

–140

–130

–110

–90

–80

100

10k

100k

10M 40M

6945 TA03b

–150

1k

1M

–100

–120

–160

RMS NOISE = 0.47°

RMS JITTER = 230fs

BW = 21kHz

PART NUMBER DESCRIPTION

COMMENTS

LTC6946

Ultralow Noise and Spurious Integer-N Synthesizer with VCO 370MHz to 6.4GHz, –226dBc/Hz Normalized In-Band Phase Noise Floor

LTC6947

Ultralow Noise and Spurious Fractional-N Synthesizer

350MHz to 6GHz, –226dBc/Hz Normalized In-Band Phase Noise Floor

LTC6948

Ultralow Noise and Spurious Frac-N Synthesizer with VCO

370MHz to 6.4GHz, –226dBc/Hz Normalized In-Band Phase Noise Floor

LTC6950

Low Phase Noise and Spurious Integer-N PLL Core with Five

Output Clock Distribution and EZSync

1.4GHz Max VCO Frequency, Additive Jitter <20fsRMS, –226dBc/Hz

Normalized In-Band Phase Noise Floor

LTC6957

Low Phase Noise, Dual Output Buffer/Driver/Logic Converter

Optimized Conversion of Sine Waves to Logic Levels, LVPECL/LVDS/

CMOS

LTC2000

16-/14-/11-Bit 2.5Gsps DAC

Superior 80dBc SFDR at 70MHz Output, 40mA Nominal Drive and High

Linearity

LTC5569

Broadband Dual Mixer

300MHz to 4GHz, 26.8dBm IIP3, 2dB Gain, 11.7dB NF, 600mW Power

LTC5588-1

Ultrahigh OIP3 I/Q Modulator

200MHz to 6GHz, 31dBm OIP3, –160.6dBm/Hz Noise Floor

LT®5575

Direct Conversion I/Q Demodulator

800MHz to 2.7GHz, 22.6dBm IIP3, 60dBm IIP2, 12.7dB NF