DA9283.006
13 July 2006
MAS9283
IC FOR 10.00 – 56.00 MHz VCXO
This is preliminary information on a new
product under development. Micro Analog
Systems Oy reserves the right to make any
changes without notice.
•
•
•
•
•
•
Low Power
Wide Supply Range
CMOS (Square Wave) Output
Very Low Phase Noise
Low Cost
Divider Function
DESCRIPTION
MAS9283 is an integrated circuit well suited to
build a VCXO for telecommunication and other
applications. To build a VCXO only one additional
component, a crystal, is needed.
FEATURES
•
•
•
•
•
Very small size
Minimal current consumption
Wide operating temperature range
Phase noise < -130 dBc/Hz at 1 kHz offset
CMOS (Square wave) output
APPLICATIONS
•
•
•
VCXO for telecommunications systems
VCXO for set-top boxes
VCXO for MPEG
BLOCK DIAGRAM
Figure 1. Block diagram of MAS9283.
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DA9283.006
13 July 2006
PIN DESCRIPTION
Pin Description
Crystal Oscillator Output
Voltage Control Input
Power Supply Ground
Crystal/Varactor Oscillator Input
Output Buffer Power Down Control
Power Supply Voltage
Buffer Output
Symbol
X2
VC
V
SS
X1
PD
V
DD
OUT
x-coordinate
186
372
543
149
330
500
919
y-coordinate
142
142
142
920
920
920
920
Note:
Because the substrate of the die is internally connected to GND, the die has to be connected to GND or
left floating. Please make sure that GND is the first pad to be bonded. Pick-and-place and all component
assembly are recommended to be performed in ESD protected area.
Note:
Pad coordinates are measured from the left bottom corner of the chip to the center of the pads. The
coordinates may vary depending on sawing width and location. However, the distances between pads are
accurate.
ABSOLUTE MAXIMUM RATINGS
Parameter
Supply Voltage
Input Pin Voltage
Power Dissipation (max)
Storage Temperature
ESD Rating
Symbol
V
DD
- V
SS
P
MAX
T
ST
HBM
Conditions
Min
-0.3
V
SS
-0.3
-55
Max
5.5
V
DD
+ 0.3
100
150
2
Unit
V
V
mW
o
C
kV
Note
RECOMMENDED OPERATION CONDITIONS
Parameter
Supply Voltage
Symbol
V
DD
I
DD
T
OP
Z
VC,LINE
S
C
L
Conditions
For 3.3 V / 5.0 V
versions
For 3.3 V versions
V
DD
= 2.8 V
Min
2.5
2.5
-40
1
30
10
Typ
3.3
3.3
3.2
Max
5.3
4.0
+85
mA
o
C
M
ppm/pF
pF
Unit
V
Note
1)
1, 2)
3)
Supply Current
Operating Temperature
Voltage Control Line
Impedance
Crystal Pulling Sensitivity
Crystal Load Capacitance
V
C
= 1.65 V
4)
Note 1:
It is recommended to connect a 1 nF capacitor between the V
DD
and V
SS
pins.
Note 2:
For 3.3 V versions MAS9283AA-AE, MAS9283AN-AR.
Note 3:
Value at 15MHz. At 40MHz I
DD
is typically 5.8 mA.
Note 4:
MAS9283AG – AL has a typical crystal load capacitance of 8.5 pF when V
C
= 2.5 V. MAS9283AT – AX
has a typical crystal load capacitance of 9 pF when V
C
= 2.5 V.
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DA9283.006
13 July 2006
ELECTRICAL CHARACTERISTICS
Parameter
Crystal Frequency Range
Voltage Control Range
Voltage Control Sensitivity
MAS9283AN – AR
Voltage Control impedance
Output Current (V
DD
= 3 V)
MAS9283 (R
L
=10kΩ)
MAS9283 (R
L
=1 kΩ)
MAS9283 (R
L
=250Ω)
MAS9283 (R
L
=50Ω)
Output Current (V
DD
= 5 V)
MAS9283 (R
L
=10kΩ)
MAS9283 (R
L
=1 kΩ)
MAS9283 (R
L
=250Ω)
MAS9283 (R
L
=50Ω)
Rise and Fall Time (10 - 50 pF)
Output Symmetry
Startup Time
Output Buffer
Enabled
Disabled
T
START
1.6
0
Symbol
f
o
V
C
V
CSENS
Z
VC
I
OUT
0.3
3.2
12.1
42.6
I
OUT
0.5
4.9
18.7
42.6
10
45
48-52
2
V
DD
0.55
55
ns
%
ms
V
3)
mA
Min
10.00
0
90
1.3
Typ
Max
56
V
DD
Unit
MHz
V
ppm/V
M
mA
2)
Note
1)
Note 1:
An R
S
< 15 crystal provides 56 MHz maximum frequency (i.e. negative resistance typically 30 ). With
an R
S
= 70 crystal the maximum frequency is typically 40 MHz (i.e. negative resistance typically 110 ).
Note 2:
VC sensitivity value depends on the crystal used. With a 30 ppm/pF crystal typical values are
MAS9283AN – AR > 90 ppm/V, MAS9283AA – AE > 75 ppm/V, MAS9283AG – AL > 60 ppm/V,
MAS9283AT – AX > 50 ppm/V.
Note 3:
If the PD pin is floating the output buffer is active. Oscillator is always running.
IC OUTLINES
Figure 2. IC outline of MAS9283.
Note 1:
MAS9283 pads are round with 80 µm diameter at opening.
Note 2:
Die map reference is the actual left bottom corner of the sawn chip.
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DA9283.006
13 July 2006
EXTERNAL COMPONENT SELECTION
MAS9283 requires a minimum number of external components for proper operation.
Quartz Crystal
The MAS9283 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 in
the following section must be followed. The
frequency of the oscillation of a quartz crystal is
determined by its “cut” and by the load capacitors
connected to it. MAS9283 incorporates on-chip
variable load capacitors that “pull” (change) the
frequency of the crystal. The crystal specified for
use with the MAS9283 is designed to have zero
frequency error when the total of on-chip + stray
capacitance is 10 pF. See Note 3 on page 2 for
other capacitance options.
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 MAS9283. 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.
Recommended Crystal Parameters:
Parameter
Initial Accuracy at 25°
C
Temperature Stability
Crystal Load Capacitance
Crystal Shunt Capacitance (Typical)
C0/C1 Ratio (Typical)
C
L
C0
Symbol
Typ
±20
±30
10
2
≤
300
Unit
ppm
ppm
pF
pF
1)
Note
Note 1.
If the crystal with a load other than 10 pF is used with MAS9283, the crystal has to have frequency offset
in order to have the nominal frequency at VC = 1.65 V. Please see table below for offset frequencies vs. crystal
load. (Values are for a typical crystal with S = 30 ppm/pF.)
Parameter
Crystal frequency
Crystal load
Offset / ppm (MAS9283AA – AE, AN – AR, VC=1.65 V)
Offset / ppm (MAS9283AG – AR, VC= 2.5V)
27
8
+30
0
27
9
0
-30
27
12.5
-105
-135
27
15
-180
-210
Unit
MHz
pF
For example:
When the desired nominal frequency of the application and the crystal load are 27.00 MHz and 12.5 pF, the
crystal nominal frequency has to be,
27.00
MHz
×
(
−
105
)
=
26.997165
MHz
.
27.00
MHz
+
10
6
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DA9283.006
13 July 2006
VOLTAGE CONTROL SENSITIVITY
MAS9283AA, MAS9283AG and MAS9283AN Voltage control sensitivity graphs have been measured by using
26.996220MHz crystal (CL 14.6pF, C1 17.0fF, C0 3.9pF). For offset see note 1 page 4.
MAS9283AA, AG, AN VC-sensitivity with 27MHz output.
270
250
230
210
190
170
150
130
110
90
70
50
30
10
-10
-30
-50
-70
-90
-110
-130
-150
-170
-190
-210
0
0.2 0.4 0.6 0.8
1
1.2 1.4 1.6 1.8
2
2.2 2.4 2.6 2.8
VC-voltage (V)
3
3.2 3.4 3.6 3.8
4
4.2 4.4 4.6 4.8
5
Frequency change (ppm)
MAS9283AA
MAS9283AG
MAS9283AN
Figure 3. Control voltage sensitivity of MAS9283.
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Microchip MCU
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