Datasheet
LTC6945
2
6945f
PIN CONFIGURATION ABSOLUTE MAXIMUM RATINGS
Supply Voltages
V
+
(V
REF
+
, V
REFO
+
, V
RF
+
, V
VCO
+
, V
D
+
) to GND ......3.6V
V
CP
+
to GND .........................................................5.5V
Voltage on CP Pin .................GND – 0.3V to V
CP
+
+ 0.3V
Voltage on All Other Pins ..........GND – 0.3V to V
+
+ 0.3V
Operating Case Temperature Range (T
C
)
(Note 2) .................................................. –40°C to 105°C
Operating Junction Temperature ........................... 125°C
Storage Temperature Range .................. –65°C to 150°C
(Note 1)
9 10
TOP VIEW
29
GND
UFD PACKAGE
28-LEAD (4mm w 5mm) PLASTIC QFN
11 12 13
28 27 26 25 24
14
23
6
5
4
3
2
1
V
REFO
+
REFO
STAT
CS
SCLK
SDI
SDO
V
D
+
V
VCO
+
GND
GND
GND
GND
GND
VCO
+
VCO
–
REF
–
REF
+
V
REF
+
CP
V
CP
+
GND
MUTE
GND
RF
–
RF
+
V
RF
+
BB
7
17
18
19
20
21
22
16
8
15
T
JMAX
= 125°C, θ
JC
= 7°C/W
EXPOSED PAD (PIN 29) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION CASE TEMPERATURE RANGE
LTC6945IUFD#PBF LTC6945IUFD#TRPBF 6945
28-Lead (4mm × 5mm) Plastic QFN
–40°C to 105°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/
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 kΩ
Input Capacitance Differential 3 pF
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
+
= V
VCO
+
= 3.3V, V
CP
+
= 5V unless otherwise
specified. All voltages are with respect to GND.