DATASHEET
LOW COST 8 TO 16 MHZ 3.3 VOLT VCXO
Description
The MK3711D is a drop-in replacement for the original
MK3711S device. Compared to these earlier devices, the
MK3711D offers a wider operating frequency range and
improved power supply noise rejection.
Used in conjunction with an external pullable quartz crystal,
this monolithic integrated circuit replaces more costly hybrid
(canned) VCXO devices. The MK3711 is designed primarily
for data and clock recovery applications within end products
such as ADSL modems, set-top box receivers, and telecom
systems.
The MK3711D exhibits a moderate VCXO gain of
120ppm/V typical, when used with a high quality external
pullable quartz crystal.
The frequency of the on-chip VCXO is adjusted by an
external control voltage input into pin VIN. Since VIN is a
high impedance input, it can be driven directly from an
PWM RC integrator circuit. Frequency output increases
with VIN voltage input. The usable range of VIN is 0 to 3V.
MK3711
Features
•
MK3711D is a drop-in replacement for the earlier
MK3711S device
•
MK3711D offers an 8-16 MHz output frequency range
and improved power supply noise rejection
•
Uses an inexpensive 8 to 16 MHz external crystal
•
On-chip VCXO with guaranteed pull range of ±115 ppm
minimum
•
•
•
•
VCXO tuning voltage 0 to 3.3 V
Packaged in 8 pin SOIC (150 mil wide)
Pb (lead) free package
Industrial temperature range available
MK3711B is Obsolete
Block Diagram
VDD
VIN
8-16 MHz
Pullable
Crystal
X1
X2
Voltage
Controlled
Crystal
Oscillator
8-16 MHz
GND
IDT™
LOW COST 8 TO 16 MHZ 3.3 VOLT VCXO
1
MK3711
REV K 051310
MK3711
LOW COST 8 TO 16 MHZ 3.3 VOLT VCXO
VCXO AND MULTIPLIER
Pin Assignment
X1
VDD
VI N
GND
1
2
3
4
MK 3 7 1 1 D
8 P i n ( 1 5 0 mi l ) S OI C
8
7
6
5
X2
DC
REF
DC
Pin Descriptions
Pin
Number
1
2
3
4
5
6
7
8
Pin
Name
XI
VDD
VIN
GND
DC
REF
DC
X2
Pin
Type
Input
Power
Input
Power
—
Output
—
Input
Pin Description
Crystal connection. Connect to the external pullable crystal.
Connect to +3.3 V (0.01uf decoupling capacitor recommended).
Voltage input to VCXO — 0 to 3.3 V analog input which controls the
oscillation frequency of the VCXO.
Connect to ground.
Do not connect anything to this pin.
VCXO CMOS level clock output matches the nominal frequency of the
crystal.
Do not connect anything to this pin.
Crystal connection. Connect to the external pullable crystal.
IDT™
LOW COST 8 TO 16 MHZ 3.3 VOLT VCXO
2
MK3711
REV K 051310
MK3711
LOW COST 8 TO 16 MHZ 3.3 VOLT VCXO
VCXO AND MULTIPLIER
External Component Selection
The MK3711 requires a minimum number of external
components for proper operation.
pF. Contact IDT applications regarding the use of a crystal
below 13.5 MHz.
The external crystal must be connected as close to the chip
as possible and should be on the same side of the PCB as
the MK3711. There should be no vias between the crystal
pins and the X1 and X2 device pins. There should be no
signal traces underneath or close to the crystal. See
application note MAN05.
Decoupling Capacitor
A decoupling capacitor of 0.01µF must be connected
between VDD (pin 2) and GND (pin 4), as close to these
pins as possible. For optimum device performance, the
decoupling capacitor should be mounted on the component
side of the PCB. Avoid the use of vias in the decoupling
circuit.
Crystal Tuning Load Capacitors
The crystal traces should include pads for small fixed
capacitors, one between X1 and ground, and another
between X2 and ground. The need for these capacitors is
determined at system prototype evaluation, and is
influenced by the particular crystal used (manufacture and
frequency) and by PCB layout. The typical required
capacitor value is 1 to 4 pF.
The procedure for determining the value of these capacitors
can be found in application note MAN05.
Series Termination Resistor
When the PCB trace between the clock output (CLK, pin 5)
and the load is over 1 inch, series termination should be
used. To series terminate a 50Ω trace (a commonly used
trace impedance) place a 33Ω resistor in series with the
clock line, as close to the clock output pin as possible. The
nominal impedance of the clock output is 20Ω
.
Quartz Crystal
The MK3711 VCXO function consists of the external crystal
and the integrated VCXO oscillator circuit. To assure the
best system performance (frequency pull range) and
reliability, a crystal device with the recommended
parameters (shown below) must be used, and the layout
guidelines discussed in the following section shown must be
followed.
The frequency of oscillation of a quartz crystal is determined
by its “cut” and by the load capacitors connected to it. The
MK3711 incorporates on-chip variable load capacitors that
“pull” (change) the frequency of the crystal. The crystal
specified for use with the MK3711 is designed to have zero
frequency error when the total of on-chip + stray
capacitance is 14 pF.
Recommended Crystal Parameters:
Initial Accuracy at 25
°
C
Temperature Stability
Aging
Load Capacitance
Shunt Capacitance, C0
C0/C1 Ratio
Equivalent Series Resistance
±20 ppm
±30 ppm
±20 ppm
14 pf
7 pF Max
250 Max
35
Ω
Max
For crystal frequencies between 13.5 MHz and 16 MHz, the
nominal crystal load capacitance specification should be 14
IDT™
LOW COST 8 TO 16 MHZ 3.3 VOLT VCXO
3
MK3711
REV K 051310
MK3711
LOW COST 8 TO 16 MHZ 3.3 VOLT VCXO
VCXO AND MULTIPLIER
Absolute Maximum Ratings
Stresses above the ratings listed below can cause permanent damage to the MK3711. These ratings, which are
standard values for IDT commercially rated parts, are stress ratings only. Functional operation of the device at these
or any other conditions above those indicated in the operational sections of the specifications is not implied.
Exposure to absolute maximum rating conditions for extended periods can affect product reliability. Electrical
parameters are guaranteed only over the recommended operating temperature range.
Item
Supply Voltage, VDD
All Inputs and Outputs
Ambient Operating Temperature (commercial)
Ambient Operating Temperature (industrial)
Storage Temperature
Soldering Temperature
7V
Rating
-0.5 V to VDD+0.5 V
0 to +70° C
-40 to +85° C
-65 to +150° C
260° C
Recommended Operating Conditions
Parameter
Ambient Operating Temperature (commercial)
Ambient Operating Temperature (industrial)
Power Supply Voltage (measured in respect to GND)
Reference crystal parameters
Min.
0
-40
+3.15
Typ.
Max.
+70
+85
+3.45
Units
°
C
°
C
V
Refer to page 3
IDT™
LOW COST 8 TO 16 MHZ 3.3 VOLT VCXO
4
MK3711
REV K 051310
MK3711
LOW COST 8 TO 16 MHZ 3.3 VOLT VCXO
VCXO AND MULTIPLIER
DC Electrical Characteristics
VDD=3.3 V ±5%
, Ambient temperature -40 to +85° C, unless stated otherwise
Parameter
Operating Voltage
Output High Voltage
Output Low Voltage
Output High Voltage (CMOS
Level)
Operating Supply Current
Short Circuit Current
VIN, VCXO Control Voltage
Symbol
VDD
V
OH
V
OL
V
OH
IDD
I
OS
V
IA
Conditions
I
OH
= -12 mA
I
OL
= 12 mA
I
OH
= -4 mA
Output = 12 MHz,
no load
Min.
3.15
2.4
Typ.
Max.
3.45
0.4
Units
V
V
V
V
VDD-0.4
7
±50
0
3.3
mA
mA
V
AC Electrical Characteristics
VDD = 3.3 V ±5%,
Ambient Temperature -40 to +85° C, unless stated otherwise
Parameter
Output Frequency
Crystal Pullability, Note 2
VCXO Gain
MK3711D, Note 3
Output Rise Time
Output Fall Time
Output Clock Duty Cycle
Maximum Output Jitter,
short term
Symbol
F
O
F
P
Conditions
0V< VIN < 3.3 V, Note 1
VIN = VDD/2 ± 1 V, Note 1
Min.
8
±115
Typ.
Max. Units
16
MHz
ppm
120
1.5
1.5
40
50
100
60
ppm/V
ns
ns
%
ps
t
OR
t
OF
t
D
t
J
0.8 to 2.0 V, C
L
=15 pF
2.0 to 0.8 V, C
L
=15 pF
Measured at 1.4 V, C
L
=15 pF
C
L
=15 pF
Note 1: External crystal device must conform with Pullable Crystal Specifications listed on page 3.
Note 2: Original MK3711S and MK3711A provided ±100 ppm crystal pullability.
Note 3: Original MK3711S and MK3711A provided 100 and 170 ppm/V respectively.
IDT™
LOW COST 8 TO 16 MHZ 3.3 VOLT VCXO
5
MK3711
REV K 051310
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