LTC6945 View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
'LTC6945' PDF : 28 Pages View PDF
LTC6945
TYPICAL APPLICATIONS
LTC6945 Wideband Frequency Hopping Local Oscillator
5V
5V
4.99k
4.99k
4.99k
4.99k
0.1μF
0.1μF
14V 0.1μF
14V 0.1μF
47μF
3.3V
0.1μF
470pF
470pF
100MHz
REF
5V 0.1μF
0.1μF 3.3V
REF– REF+
VREFO+
VREF+
CP VCP+VGVNCOD+
REFO
GND
LTC6945
STAT
GND
CS
GND
GND
SPI BUS
SCLK
GND
SDI
GND
SDO
O_DIV = 2
VCO+
3.3V
VD+
VCO–
0.1μF MUTE GND RF– RF+ VRF+ BB
LT1678IS8 +
–
22nF
LOOP BANDWIDTH = ~7.6kHz
470pF
267nF
274Ω
470pF
51.1Ω
47μF
3.3V
0.1μF
5V 0.1μF
3.3V 0.01μF
100pF
100pF
100Ω
VTUNE
13.3nF
12V RFMD
UMS-1400-A16-G
0.1μF 3.3V
REF– REF+
VREFO+
VREF+
CP
VCP+VGVNCOD+
REFO
GND
LTC6945
STAT
GND
700MHz TO 1400MHz
SPI BUS
3.3V
0.1μF
CS
GND
GND
SCLK
GND
SDI
GND
SDO
O_DIV = 2
VCO+
VD+
VCO–
MUTE GND RF– RF+ VRF+ BB
LT1678IS8 +
–
22nF
LOOP BANDWIDTH = ~7.6kHz
267nF
274Ω
3.3V 0.01μF
100Ω
VTUNE
13.3nF
12V RFMD
UMS-1400-A16-G
100pF
700MHz TO 1400MHz
100pF
MUTE1
1.0μF
MUTE2
1.0μF
3.3V 0.01μF
MUTE1 3.3V
0V
3.3V 0.01μF
180nH
3.3V
270pF
50Ω
180nH
3.3V
270pF
3.3V
MUTE2 0V
100ns
180nH
3.3V
270pF
50Ω
180nH
3.3V
270pF
LO2 = 350MHz TO 700MHz
LO1 = 350MHz TO 700MHz
POWER
COMBINER
1
S LO OUT
2
6945 TA02a
Frequency Hopping
LOOUT Frequency,
LO1 = 450MHz, LO2 = 700MHz
750
650
550
450
MUTE1
3
MUTE2
2
1
0
–0.6 –0.4 –0.2 0 0.2
TIME (μs)
0.4 0.6
6945 TA02b
Frequency Hopping
LOOUT Power,
LO1 = 450MHz, LO2 = 700MHz
–3.5
–4.0
–4.5
–5.0
MUTE1
3
MUTE2
2
1
0
–0.6 –0.4 –0.2 0 0.2
TIME (μs)
0.4 0.6
6945 TA02c
Frequency Hopping
LOOUT Spectrum,
LO1 = 450MHz Muted,
LO2 = 700MHz
0
–10
fPFD = 1MHz
OD = 2
–20
–30
–40
–50
–60
–70
–80
–90
–100
–95dBc
–110
400 450 500 550 600 650 700 750
FREQUENCY (MHz)
6945 TA02d
6945f
26
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