2001-03-08 Page
1
MDST-0001-01
www.vaishali.com
Vaishali Semiconductor 1300 White Oaks Road, Ste. 200 Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063
Applications
= Telecom switching
= Set-top boxes
= HDTV
= MPEG Video clock source
General Description
The Vaishali VT83205 is a single-chip, integrated VCXO and Phase Locked Loop (PLL) clock synthesizer.
The device uses the VCXO and an analog Phase-Locked Loop (PLL) to accept a 10 MHz to 14.318 MHz,
30pF (pull range of 200 ppm) crystal input, in order to produce either one or two output clocks. A 0 to 3V
control signal is used to fine tune the output clock frequency in the 100ppm range. Select inputs SO:S2
are used for frequency and output selection.
Features
= 3.3V supply operation
= Packaged in 16-pin SOIC & QSOP packages.
= Replaces separate VCXO and multiplier
= Uses inexpensive pullable crystal
= On-chip VCXO with 200 ppm pull range (100
ppm)
= 5V-tolerant control inputs
= Zero ppm synthesis error in both clocks
VT83205
3.3V Low Phase Noise VCXO
(Voltage-Controlled Crystal Oscillator)
and PLL Clock Synthesizer
Figure 1. Functional Block Diagram
CLK1
CLK2
VDD1
VDD2
X2
Load Cap Control
Low
Phase
Noise
PLL
Output
Buffer
Output
Buffer
osc
Load
Caps
OE
10-14 MHz
Pullable
Crystal
S2:S0
VIN
X1
VT83205
2001-03-08 Page
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MDST-0001-01
www.vaishali.com
Vaishali Semiconductor 1300 White Oaks Road, Ste 200 Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063
Figure 2. Pin Configuration
Table 1. Pin Description
Name Pin
# Type
Description
X1
1
XI
Crystal connection. Connect to a pullable crystal of 1014.318 MHz
V
DD
1 2,3 P Core
V
DD
. Connect to 3.3V
VIN
4
I
Voltage input to VCXO. Zero to 3V signal controls the frequency of the VCXO.
GND
5,6,13
P
Connect to ground.
S2
7
I
Select input #2. Selects outputs per Table 2
OE
8
I
Active HIGH Output enable . Outputs in Hi-Z state when LOW
CLK1
9
O
Clock output #1 per Table 2.
SO
10
I
Select input #0. Selects output per Table 2
V
DD
2 11 P Output
V
DD
. Connect to 3.3V
CLK2
12
O
Clock output #2 per Table 2
S1
14
I
Select input #1. Selects outputs per Table 2
NC
15
-
There is no internal connection to this pin.
X2
16
XO
Crystal connection. Connect to a pullable crystal of 10 MHz 14.318 MHz.
Legend: I = Input
O = Output
P = Power supply connection
XI, XO = Crystal connections.
Table 2. Pullable Crystal Specifications
Parameter Value
Correlation (load) capacitance
30 pF
C0/C1 240
max
ESR
35
max
Operating Temperature
0
C to +70
C
Initial Accuracy
20 ppm
Temperature + Aging Stability
50 ppm
VT83205 Pinout
V
DD
2
V
DD
1
GND
GND
CLK2
CLK1
X1
V
DD
1
VIN
GND
S2
NC
S1
S0
OE
X2
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
VT83205
2001-03-08 Page
3
MDST-0001-01
www.vaishali.com
Vaishali Semiconductor 1300 White Oaks Road, Ste 200 Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063
Table 3 Clock Selection Table (OE = High)
S2 S1 S0
CLK1
CLK2
0 0 0 REF/4
REF/2
0 0 M
(1)
OFF
X
0.666
0 0 1
OFF
X
2.6666
0 1 0
OFF
X
4
0 1 M
(1)
OFF
X
1.5
0 1 1
OFF
X
1.3333
1 0 0
Test
Test
1 0 M
(1)
OFF
X
4
1 0 1
OFF
X
2
1 1 0
OFF
X
3
1 1 M
(1)
OFF
X
5
1 1 1
OFF
X
6
Note:
1.
SO has three valid states: 0 = V
IN
0.5V
1 = V
IN
V
DD
0.5
M = 0.5V
<
V
IN
<
V
DD
0.5V
Table 4 Absolute Maximum Ratings
Parameter Conditions
Min
Typ
Max
Units
Supply voltage, V
DD
Referenced to GND
5
V
Inputs and Clock Outputs
Referenced to GND
-0.5
VDD+0.5
V
Soldering Temperature
Max of 10 seconds
260
C
Storage temperature
-65
150
C
Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device.
These ratings are stress specifications only and correct functional operation of the device at these or any
other conditions above those listed in the operational sections of the specifications is not implied. Exposure
to absolute maximum rating conditions for extended periods may affect product reliability.
Table 5 Operating Conditions
Parameter Conditions
Min
Typ
Max
Units
Operating Voltage, V
DD
3.15
3.3
3.45
V
Input High Voltage, V
IH
, X1 pin only
2.5
V
Input Low Voltage, V
IL
, X1 pin only
0.4
V
Input High Voltage, V
IH
, binary inputs
S2, S1, OE
2
V
Input Low Voltage, V
IL
, binary inputs
S2, S1, OE
0.8
V
Input High Voltage, V
IH
, trinary input
S0
V
DD
-0.5
V
Input Low Voltage, V
IL
, trinary input
S0
0.5
V
Operating Temperature
0
70
C
VCXO control voltage, V
IN
0
3
V
VT83205
2001-03-08 Page
4
MDST-0001-01
www.vaishali.com
Vaishali Semiconductor 1300 White Oaks Road, Ste 200 Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063
Table 6. DC Electrical Characteristics
T
A
= 0
C to +70
C, V
DD
= 3.15 V to 3.45 V
Parameter Condition
Min
Typ
(1)
Max Units
Output High Voltage, V
OH
I
OH
=-25mA 2.4 V
Output Low Voltage, V
OL
I
OL
=25mA
0.4
V
Operating Supply Current, I
DD
No
Load
38
mA
Short Circuit Current
Each output
85
mA
Input Capacitance
S2:0, OE
7
pF
Note
:
1. Typical values are at V
DD
= 3.3V and 25C
Table 7. AC Electrical Characteristics
T
A
= 0
C to +70
C, V
DD
= 3.15 V to 3.45 V
Symbol Parameter Condition
Min
Typ
Max
Units
Fosc
Input Crystal Frequency
10
14.318
MHz
Tr
Output Clock Rise Time
0.8 to 2.0V
1.5
ns
tf
Output Clock Fall Time
2.0 to 0.8V
1.5
ns
t
od
Output Clock Duty Cycle
At V
DD
/2 40 60 %
tpZL, tpZH Enable Time. OE to CLK
C
L
= 50pf
5
6.5
ns
tpLZ, tpHZ Disable Time. OE to CLK
C
L
= 50pf
4
5.5
ns
t
jit
(pk-pk)
Maximum Absolute Jitter
(Peak to Peak)
100
ps
Phase Noise, relative to carrier
10 KHz offset
-115
dBc/Hz
Output pullability
0V <V
IN
<3V 100
ppm
Note:
1. Typical values are at V
DD
= 3.3V and 25C
Figure 3. External Crystal Connection Block Diagram
Ordering Information
Part Number
Marking
Shipping/Packaging
No. of Pins
Package
Temperature
VT83205Q VT83205Q Tubes
16
QSOP
0
C to +70
C
VT83205QX
VT83205Q
Tape & Reel
16
QSOP
0
C to +70
C
VT83205S1 VT83205S1 Tubes
16
SOIC
0
C to +70
C
VT83205S1X
VT83205S1
Tape & Reel
16
SOIC
0
C to +70
C
VT83205/D
Die
0
C to +70
C
X2
X1
33pF
C
X2
33pF
C
X1
XTAL OSC
PLL
CLOCK
GEN
OE
External
Crystal
X2
X1
20pF
(C
X2
)
20pF
C
X1
XTAL OSC
PLL
CLOCK
GEN
OE
External Crystal
Load Capacitors
10-14MHz
Pullable Crystal
Clk 1
Clk
2
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