VAISH VT73127/DW

Preliminary
VT73127
27 MHz 3.3V VCXO with Output Enable
Applications
•=
Crystal-driven clock source
General Description
The Vaishali VT73127 is a single-chip, low-jitter Voltage-Controlled-Crystal-Oscillator. The device accepts
a 27 MHz, 20 pF crystal input, and produces a low jitter output at the same frequency. The output is
enabled when OE is logic HIGH and goes into high impedance state when OE is logic LOW. A 0 to 3.0V
control signal is used to fine tune the output clock frequency in the ±100ppm range.
Features
•=
3.3V operating voltage
•=
On-chip oscillator with 200 ppm pull range (±100 ppm)
•=
Uses inexpensive pullable crystals
•=
Active High output enable
•=
12mA drive capability at TTL levels
•=
Die only
Figure 1. Functional Block Diagram
VDD1
VDD2
Load Cap Control
VIN
X2
Output
Buffer
27 MHz
Pullable
Crystal
Load
Caps
CLK
Oscillator
OE
X1
GND
GND
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MDST-0012-02
www.vaishali.com
Vaishali Semiconductor 747 Camden Avenue, Suite C Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063
2001-08-06
VT73127
Preliminary
Figure 2. Pad Configuration
VT73127/D
X1
X2
1
9
VDD1
2
8
GND
VIN
3
7
VDD2
GND
4
6
OE
5
CLK
Table 1. Pad Description
Pad
Type
X1
Name
1
Xi
Crystal connection. Connect to a 27 MHz pullable crystal
Description
VDD1
2
P
Core VDD. Connect to 3.3V
VIN
3
I
Tuning control input. Zero to 3.3V signal controls the frequency of the VCXO.
GND
4
P
Connect to ground.
CLK
5
O
Clock output
OE
6
I
Active HIGH output enable. When LOW, the output is held in a tri-state condition
VDD2
7
P
Output buffer VDD . Connect to 3.3V
GND
8
P
Connect to ground.
X2
9
Xi
Crystal connection. Connect to a 27 MHz pullable crystal.
Legend: I = Input
O = Output
P = Power supply connection
Xi = Crystal connections.
Table 2. Absolute Maximum Ratings
Parameter
Conditions
Supply voltage, VDD
Referenced to GND
Inputs and Clock Outputs
Referenced to GND
Soldering Temperature
Max of 10 seconds
Storage temperature
Min
Typ
-0.5
-65
Max
Units
7
V
VDD+0.5
V
260
°C
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 3. Operating Conditions
Parameter
Conditions
Min
Operating Voltage, VDD
3.0
Input High Voltage, VIH, X1 pin only
2.5
Input Low Voltage, VIL, X1 pin only
Operating Temperature
Input crystal accuracy
0
Typ
3.3
Max
3.6
Units
V
V
0.4
V
70
°C
±30
ppm
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MDST-0012-02
www.vaishali.com
Vaishali Semiconductor 747 Camden Avenue, Suite C Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063
2001-08-06
VT73127
VCXO control voltage, VIN
Preliminary
0
3.3
V
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MDST-0012-02
www.vaishali.com
Vaishali Semiconductor 747 Camden Avenue, Suite C Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063
2001-08-06
VT73127
Preliminary
Table 4. DC Electrical Characteristics
TA = 0°C to +70°C, VDD = 3.0 V to 3.6 V
Parameter
Condition
(1)
Min
Typ
Max
2.4
Units
Output High Voltage, VOH
IOH=-12mA
V
Output Low Voltage, VOL
IOL=12mA
Operating Supply Current, IDD
No Load
25
mA
Short Circuit Current
Each output
±85
mA
7
pF
0.4
Input Capacitance
V
Note:
1. Typical values are at VDD = 3.3V and 25°C
Table 5. AC Electrical Characteristics
TA = 0°C to +70°C, VDD = 3.0 V to 3.6 V
Symbol
Parameter
Condition
Min
Typ
Max
27
Units
fosc
Input Crystal Frequency
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
tPZL
Output Enable Time
6.5
ns
tPZH
(OE to CLK)
tPLZ
Output Disable Time
6.5
ns
tPHZ
(OE to CLK)
tod
Output Clock Duty Cycle
60
%
tjit (pk – pk)
Maximum Absolute Jitter
150
ps
At VDD/2
40
MHz
(Peak to Peak)
0V ≤VIN ≤ 3.3V
Output pullability
±100
ppm
Note:
1. Typical values are at VDD = 3.3V and 25°C
Table 6 Pullable Crystal Specifications
Parameter
Correlation (Load) Capacitance
Capacitance Ratio
Symbol
CL
CO/C1
Value
20pF
240 max
ESR
50 Ω max
Initial Accuracy
±30ppm
Temperature and Aging Stability
±50ppm
Ordering Information
VT73127
Part Number
VT73127/D
VT73127/DW
Marking
Shipping/Packaging
Dice in waffle-pack
Dice in wafer form
No. of Pads
Package
Temperature
o
o
0 C to +70 C
o
o
0 C to +70 C
Page 4
MDST-0012-02
www.vaishali.com
Vaishali Semiconductor 747 Camden Avenue, Suite C Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063
2001-08-06