IDT MK3722 Vcxo plus audio clock for stb packaged in 16-pin tssop Datasheet

DATASHEET
MK3722
VCXO PLUS AUDIO CLOCK FOR STB
Description
Features
The MK3722 is a low cost, low jitter, high performance
VCXO and PLL clock synthesizer designed to replace
expensive discrete VCXOs and multipliers. The patented
on-chip Voltage Controlled Crystal Oscillator accepts a 0 to
3.3 V input voltage to cause the output clocks to vary by
±115 ppm. Using IDT’s analog/digital Phase-Locked Loop
(PLL) techniques, the device uses an inexpensive 27 MHz
pullable crystal input to produce a reference output and a
selectable audio clock.
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IDT manufactures the largest variety of VCXO based timing
devices for all applications. Consult IDT to eliminate
VCXOs, crystals, and oscillators from your board.
• VCXO tuning voltage of 0 to 3.3 V
• Advanced, low power, sub-micron CMOS process
Packaged in 16-pin TSSOP
Pb (lead) free package
Replaces a VCXO and oscillator
Operating voltage of 3.3V
Provides output of 27 MHz plus audio clock
Uses an inexpensive 27 MHz pullable crystal
On-chip patented VCXO with pull range of 230 ppm
(minimum)
The frequency of the on-chip VCXO is adjusted by an
external control voltage connected to VIN. Because VIN is
a high impedance input, it can be driven directly from an
PWM RC integrator circuit.
Block Diagram
VDD
3
PLL/Clock
Synthesis
Circuitry
3
S2:S0
VIN
X1
27 MHz
Pullable
Crystal
X2
Voltage
Controlled
Crystal
Oscillator
ACLK
27MHz
3
GND
IDT™ VCXO PLUS AUDIO CLOCK FOR STB
1
PDTS
MK3722
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MK3722
VCXO PLUS AUDIO CLOCK FOR STB
VCXO AND SYNTHESIZER
Pin Assignment
Audio Clock Select Table
X2
1
16
S1
S2
S1
S0
ACLK (MHz)
X1
2
15
NC
0
0
0
8.192
VD D
3
14
VD D
0
0
1
11.2896
VD D
4
13
S0
0
1
0
12.288
VIN
5
12
27M
0
1
1
16.9344
GND
6
11
GND
GND
7
10
AC LK
1
0
0
18.432
PD TS
8
9
1
0
1
16.384
1
1
0
22.5792
1
1
1
24.576
S2
16 Pin 4.40m m body, 0.65m m pitch TSSO P
Pin Descriptions
Pin
Number
Pin
Name
Pin
Type
1
X2
Output
Crystal connection. Connect to a 27MHz fundamental mode
pullable crystal.
2
X1
Input
Crystal connection. Connect to a 27MHz fundamental mode
pullable crystal.
3
VDD
Power
Connect to +3.3 V.
4
VDD
Power
Connect to +3.3 V.
5
VIN
Input
Voltage input to VCXO. Zero to 3.3V signal which controls the
VCXO frequency.
6
GND
Power
Connect to ground.
7
GND
Power
Connect to ground.
8
PDTS
Power
Power Down Tri-state. This pin powers down entire chip and
tri-states the outputs when low. Internal pull-up.
9
S2
Input
Select input S2. Selects ACLK per table above. Internal pull-up.
10
ACLK
Output
Audio clock output per table above.
11
GND
Power
Connect to ground.
12
27M
Output
27MHz reference clock output.
13
S0
Input
Select input S0. Selects ACLK per table above. Internal pull-up.
14
VDD
Power
Connect to +3.3V.
15
NC
--
16
S1
Input
IDT™ VCXO PLUS AUDIO CLOCK FOR STB
Pin Description
No connect. Do not connect anything to this pin.
Select input S1. Selects ACLK per table above. Internal pull-up.
2
MK3722
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MK3722
VCXO PLUS AUDIO CLOCK FOR STB
VCXO AND SYNTHESIZER
External Component Selection
capacitors, one between X1 and ground, and another
between X2 and ground. Stuffing of these capacitors on the
PCB is optional. 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 MK3722 requires a minimum number of external
components for proper operation.
Decoupling Capacitors
Decoupling capacitors of 0.01µF should be connected
between VDD and GND on pins 3 and 4, pins 6 and 7, and
pins 11 and 14 as close to the MK3722 as possible. For
optimum device performance, the decoupling capacitors
should be mounted on the component side of the PCB.
Avoid the use of vias in the decoupling circuit.
The procedure for determining the value of these capacitors
can be found in application note MAN05.
Series Termination Resistor
When the PCB traces between the clock outputs and the
loads are 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 MK3722 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 meeting IDT’ recommended
parameters must be used, and the layout guidelines
discussed in the following section must be followed.
See Application Note MAN05 for a full list of crystal
parameters.
The frequency of oscillation of a quartz crystal is determined
by its “cut” and by the load capacitors connected to it. The
MK3722 incorporates on-chip variable load capacitors that
“pull” (change) the frequency of the crystal. The crystal
specified for use with the MK3722 is designed to have zero
frequency error when the total of on-chip + stray
capacitance is 14pF.
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 MK3722. There should be no via’s between the crystal
pins and the X1 and X2 device pins. There should be no
signal traces underneath or close to the crystal.
Crystal Tuning Load Capacitors
The crystal traces should include pads for small fixed
IDT™ VCXO PLUS AUDIO CLOCK FOR STB
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MK3722
REV G 051310
MK3722
VCXO PLUS AUDIO CLOCK FOR STB
VCXO AND SYNTHESIZER
Absolute Maximum Ratings
Stresses above the ratings listed below can cause permanent damage to the MK3722. 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
Rating
Supply Voltage, VDD
7V
All Inputs and Outputs
-0.5 V to VDD+0.5 V
Ambient Operating Temperature
0 to +70° C
Storage Temperature
-65 to +150° C
Soldering Temperature
260° C
Recommended Operation Conditions
Parameter
Min.
Max.
Units
0
+70
°C
+3.15
+3.45
V
Ambient Operating Temperature
Power Supply Voltage (measured in respect to GND)
Reference crystal parameters
Typ.
Refer to page 3
DC Electrical Characteristics
VDD=3.3 V ±5% , Ambient temperature 0 to +70° C, unless stated otherwise
Parameter
Symbol
Conditions
Operating Voltage
VDD
Output High Voltage
VOH
IOH = -12 mA
Output Low Voltage
VOL
IOL = 12 mA
Output High Voltage (CMOS Level)
VOH
IOH = -4 mA
Input High Voltage (S1:S0)
Min.
Typ.
3.15
Max.
Units
3.45
V
2.4
V
0.4
V
VDD-0.4
V
VIH
2.0
V
Input High Voltage (S2)
VIH
2.5
V
Input Low Voltage (S1:S0)
VIL
0.8
V
Input Low Voltage (S2)
VIL
0.5
V
Operating Supply Current
IDD
Short Circuit Current
IOS
VIN, VCXO Control Voltage
VIA
On Chip Pull-up Resistor, inputs
RPU
S0, S1, S2
150
kΩ
Input Capacitance
CIN
S0, S1, S2
5
pF
20
Ω
Nominal Output Impedance
IDT™ VCXO PLUS AUDIO CLOCK FOR STB
No load, 2
outputs
11
mA
±50
mA
0
ZOUT
4
3.3
MK3722
V
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MK3722
VCXO PLUS AUDIO CLOCK FOR STB
VCXO AND SYNTHESIZER
AC Electrical Characteristics
VDD = 3.3 V ±5%, Ambient Temperature 0 to +70° C, unless stated otherwise
Parameter
Symbol
Crystal Pullability
fP
VCXO Gain
Conditions
Min.
0V< VIN < 3.3 V, Note 1
+ 100
Typ.
Max. Units
ppm
VIN = VDD/2 + 1 V, Note 1
80
ppm/V
Output Rise Time
tOR
0.8 to 2.0 V, CL=15 pF
0.75
1.5
ns
Output Fall Time
tOF
2.0 to 0.8 V, CL=15 pF
0.75
1.5
ns
Output Clock Duty Cycle
tD
Measured at 1.65 V, CL=15 pF
50
60
%
Maximum Output Jitter,
short term
tJ
CL=15 pF
40
+150
ps
Note 1: External crystal device must conform with Pullable Crystal Specifications listed on page 3.
Thermal Characteristics
Parameter
Thermal Resistance Junction to
Ambient
Thermal Resistance Junction to Case
IDT™ VCXO PLUS AUDIO CLOCK FOR STB
Symbol
Conditions
Min.
Typ.
Max. Units
θJA
Still air
78
° C/W
θJA
1 m/s air flow
70
° C/W
θJA
3 m/s air flow
68
° C/W
37
° C/W
θJC
5
MK3722
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MK3722
VCXO PLUS AUDIO CLOCK FOR STB
VCXO AND SYNTHESIZER
Package Outline and Package Dimensions (16-pin TSSOP, 4.40 mm Body, 0.65 mm Pitch)
Package dimensions are kept current with JEDEC Publication No. 95
Millimeters
16
Symbol
E1
A
A1
A2
b
C
D
E
E1
e
L
α
E
INDEX
AREA
1 2
D
A
2
Min
Inches
Max
-1.20
0.05
0.15
0.80
1.05
0.19
0.30
0.09
0.20
4.90
5.1
6.40 BASIC
4.30
4.50
0.65 Basic
0.45
0.75
0°
8°
Min
Max
-0.047
0.002
0.006
0.032
0.041
0.007
0.012
0.0035 0.008
0.193
0.201
0.252 BASIC
0.169
0.177
0.0256 Basic
0.018
0.030
0°
8°
A
A
1
c
-Ce
b
SEATING
PLANE
L
.10 (.004)
C
Ordering Information
Part / Order Number
Marking
Shipping Packaging
Package
Temperature
MK3722GLF
MK3722GLFTR
MK3722GL
MK3722GL
Tubes
Tape and Reel
16-pin TSSOP
16-pin TSSOP
0 to +70° C
0 to +70° C
"LF" suffix to the part number are the Pb-Free configuration and are RoHS compliant.
While the information presented herein has been checked for both accuracy and reliability, Integrated Device Technology (IDT) assumes
no responsibility for either its use or for the infringement of any patents or other rights of third parties, which would result from its use. No
other circuits, patents, or licenses are implied. This product is intended for use in normal commercial applications. Any other applications
such as those requiring extended temperature range, high reliability, or other extraordinary environmental requirements are not
recommended without additional processing by IDT. IDT reserves the right to change any circuitry or specifications without notice. IDT
does not authorize or warrant any IDT product for use in life support devices or critical medical instruments.
IDT™ VCXO PLUS AUDIO CLOCK FOR STB
6
MK3722
REV G 051310
MK3722
VCXO PLUS AUDIO CLOCK FOR STB
VCXO AND SYNTHESIZER
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© 2006 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice. IDT and the IDT logo are trademarks of Integrated Device
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