Datasheet
LTC6945
28
6945f
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507
●
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2011
LT 1211 • PRINTED IN USA
RELATED PARTS
TYPICAL APPLICATION
PART NUMBER DESCRIPTION COMMENTS
LTC6946-x Ultralow Noise and Spurious Integer-N PLL with
Integrated VCO
VCO L
M(OUT)
= –141dBc/Hz at f
RF
= 900MHz, f
OFFSET
= 1MHz
LTC5540/LTC5541
LTC5542/LTC5543
High Dynamic Range Down Mixers 8dB Conversion Gain, 26.4dBm IIP3, 9.6dB NF, 600MHz to 4GHz
LTC5590/LTC5591
LTC5592/LTC5593
High Linearity Dual Mixers 600MHz to 4.5GHz, 8.5dB Gain, 26.2dBm IIP3, 9.9dB NF
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
LTC6945 Wideband Point-to-Point Radio Local Oscillator
V
VCO
+
GND
GND
GND
GND
GND
VCO
+
VCO
–
V
REFO
+
REFO
STAT
CS
SCLK
SDI
SDO
V
D
+
MUTE GND RF
–
GND
LTC6945
O_DIV = 2
RF
+
V
RF
+
BB
REF
–
3.3V
0.1μF
100MHz
REF
REF
+
V
REF
+
CP V
CP
+
GND
+
0.01μF
100pF
1.0μF
18.3nF
LT1678IS8
113Ω
4.99k
51.1Ω
4.99k
230nF
470pF
470pF
0.1μF
0.1μF
47μF
3.3V
3.3V
SPI BUS
0.1μF
0.01μF
68nH68nH
3.3V
3.3V
LO OUT
4900MHz TO 5900MHz
IN STEPS OF 5MHz
3.3V
100pF
50Ω
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
100Ω
V
TUNE
+
–
Radio Local Oscillator
Phase Noise, f
RF
= 5725MHz
OFFSET FREQUENCY (Hz)
–140
PHASE, NOISE (dBc/Hz)
–130
–110
–90
–80
100 10k 100k 10M 40M
6945 TA03b
–150
1k
1M
–100
–120
–160
RMS NOISE = 0.47°
RMS JITTER = 230fs
f
PFD
= 5MHz
BW = 21kHz