Datasheet

LTC6946
3
6946fa
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
C
= 25°C. V
REF
+
= V
REF0
+
= V
D
+
= V
RF
+
= 3.3V, V
CP
+
= V
VCO
+
= 5V unless otherwise
specified (Note 2). All voltages are with respect to GND.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Reference Inputs (REF
+
, REF
)
f
REF
Input Frequency
l
10 250 MHz
V
REF
Input Signal Level Single Ended
l
0.5 2 3.3 V
P-P
Input Slew Rate
l
20 V/μs
Input Duty Cycle 50 %
Self-Bias Voltage
l
1.65 1.85 2.25 V
Input Resistance Differential
l
6.2 8.4 11.6
Input Capacitance Differential 3 pF
Reference Output (REFO)
f
REFO
Output Frequency
l
10 250 MHz
P
REFO
Output Power f
REFO
= 10MHz, R
LOAD
= 50Ω
l
–0.2 3.2 dBm
Output Impedance, Disabled 800 Ω
VCO
f
VCO
Frequency Range LTC6946-1 (Note 3)
LTC6946-2 (Note 3)
LTC6946-3 (Note 3)
l
l
l
2.240
3.080
3.840
3.740
4.910
5.790
GHz
GHz
GHz
K
VCO
Tuning Sensitivity LTC6946-1 (Notes 3, 4)
LTC6946-2 (Notes 3, 4)
LTC6946-3 (Notes 3, 4)
4.7 to 7.2
4.7 to 7.0
4.0 to 6.0
%Hz/V
%Hz/V
%Hz/V
RF Output (RF
+
, RF
)
f
RF
Output Frequency
l
0.373 5.790 GHz
O Output Divider Range All Integers Included
l
16
Output Duty Cycle 50 %
Output Resistance Single Ended, Each Output to V
RF
+
l
111 136 159 Ω
Output Common Mode Voltage
l
2.4 V
RF
+
V
P
RF(SE)
Output Power, Single Ended,
f
RF
= 900MHz
RFO[1:0] = 0, R
Z
= 50Ω, LC Match
RFO[1:0] = 1, R
Z
= 50Ω, LC Match
RFO[1:0] = 2, R
Z
= 50Ω, LC Match
RFO[1:0] = 3, R
Z
= 50Ω, LC Match
l
l
l
l
–9.7
–6.8
–3.9
–1.2
–6.0
–3.6
–0.4
2.3
dBm
dBm
dBm
dBm
Output Power, Muted R
Z
= 50Ω, Single Ended, f
RF
= 900MHz, O = 2 to 6
l
–60 dBm
Mute Enable Time
l
110 ns
Mute Disable Time
l
170 ns
Phase/Frequency Detector
f
PFD
Input Frequency
l
100 MHz
Lock Indicator, Available on the STAT Pin and via the SPI-Accessible Status Register
t
LWW
Lock Window Width LKWIN[1:0] = 0
LKWIN[1:0] = 1
LKWIN[1:0] = 2
LKWIN[1:0] = 3
3.0
10.0
30.0
90.0
ns
ns
ns
ns
t
LWHYS
Lock Window Hysteresis Increase in t
LWW
Moving from Locked State to
Unlocked State
22 %
Charge Pump
I
CP
Output Current Range 12 Settings (See Table 5) 0.25 11.2 mA
Output Current Source/Sink Accuracy All Settings V
CP
= V
CP
+
/2 ±6 %
Output Current Source/Sink Matching I
CP
= 250μA to 1.4mA, V
CP
= V
CP
+
/2
I
CP
= 2.0mA to 11.2mA, V
CP
= V
CP
+
/2
±3.5
±2
%
%