T73227-M08 [ETC]
27 MHz VCXO Clock Generator IC; 27 MHz的VCXO时钟发生器IC
| 型号： | T73227-M08 |
| 厂家： | 
ETC |
| 描述： | 27 MHz VCXO Clock Generator IC |
| 文件： | 总5页 (文件大小：79K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
T73227
27 MHz VCXO Clock Generator IC
October 2002
1.0 Features
3.0 Description
•
One-chip tunable voltage controlled crystal oscillator
(VCXO) allows precise system frequency tuning
The T73227 is a single-chip, low-jitter Voltage-Controlled-
Crystal-Oscillator. The device accepts a 27 MHz, 20 pF
crystal, and produces a low jitter output at the same fre-
quency. A 0 to 3.0V control signal is used to fine tune the
output clock frequency in the ±100ppm range. This finds
use in systems that have frequency matching require-
ments, such as digital satellite receivers.
•
•
•
3.3V operation
8 pin SOIC and MSOP packages
Uses inexpensive 20pF pullable crystals with no
external capacitors required.
•
12mA drive capability at TTL levels
2.0 Applications
•
•
•
Set-top boxes
MPEG Video clock source
Oscillator replacement
Figure 1: Block Diagram
VDD1
VDD2
Load Cap Control
VIN
X2
CLK
Output
Buffer
27 MHz
Pullable
Crystal
Load
Caps
Oscillator
X1
GND2
GND1
This document contains information on a preproduction product. Specifications and information herein are subject to change without notice.
10.29.02
ISO9001
T73227
27 MHz VCXO Clock Generator IC
October 2002
8-pin SOIC/MSOP
X1
X2
1
2
3
4
8
7
6
5
VDD1
GND1
VDD2
CLK
VIN
GND2
Table 1: Pin Descriptions
PIN
TYPE
NAME
DESCRIPTION
1
2
Xi
P
I
X1
VDD1
VIN
Crystal Connection. Connect to a 27 MHz Pullable Crystal
Core VDD. Connect to 3.3V
Voltage input to VCXO. Zero to 3.3V Signal Controls the Frequency of the
VCXO.
3
4
5
6
7
8
P
O
P
GND2
CLK
Connect to Ground.
Clock Output
VDD2
GND1
X2
Pad Driver VDD . Connect to 3.3V
Connect to Ground.
P
Xi
Crystal Connection. Connect to a 27 MHz pullable crystal.
Legend: I = Input
O = Output
P = Power supply connection
Xi = Crystal connections.
2
10.29.02
ISO9001
T73227
27 MHz VCXO Clock Generator IC
October 2002
4.0 Functional Block Description
The VCXO provides a tunable, low-jitter frequency reference. Loading capacitance for the crystal is internal to the
T73227. No external components (other than the crystal resonator itself) are required for operation of the VCXO.
Tuning of the VCXO frequency is accomplished by varying the voltage on Vin (Pin 3).
The oscillator operates the crystal resonator in the parallel-resonant mode. Crystal warping, or the “pulling” of the crys-
tal oscillation frequency, is accomplished by altering the effective load capacitance presented to the crystal by the os-
cillator circuit. The actual amount that changing the load capacitance alters the oscillator frequency will be dependent
on the characteristics of the crystal as well as the oscillator circuit itself.
Specifically, the motional capacitance of the crystal (usually referred to by crystal manufacturers as C1), the static ca-
pacitance of the crystal (C0), and the load capacitance (CL) of the oscillator determine the “warping” or “pulling”
capability of the crystal in the oscillator circuit. A simple
formula to obtain the warping capability of a crystal oscil-
T73227 Typical VCXO Deviation vs. Vin
lator is:
6
150
×
(
+
−
)
×
C1 CL2 CL1 10
2×
∆f ( ppm) =
(
)
×
(
+
)
C0 CL2 C0 CL1
where CL1 and CL2 are the two extremes of the applied
load capacitance.
100
50
0
EXAMPLE: A crystal with the following parameters is
used. With C1 = 0.025pF, C0 = 6pF, CL1 = 10pF, and CL2
= 20pF, the tuning range is
-50
-100
-150
6
0.025×
(
20 −10
)
×
10
.
= 300ppm
∆f =
2×
(
6 + 20 6 +10
)
×
(
)
0.1
0.4
0.7
0.9
1.2
1.5
Vin
1.8
2.0
2.3
2.5
2.7
5.0 Electrical Specifications
Table 2: Absolute Maximum Ratings
Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. These conditions represent a stress rating only, and functional operation of the device at
these or any other conditions above the operational limits noted in this specification is not implied. Exposure to maximum rating conditions for extended conditions may affect device performance,
functionality, and reliability.
PARAMETER
SYMBOL
MIN.
MAX.
UNITS
Supply Voltage (VSS = ground)
Input Voltage, dc
VDD
VI
VSS-0.5
VSS-0.5
VSS-0.5
-25
5
VDD+0.5
VDD+0.5
25
V
V
Output Voltage, dc
VO
IIK
V
Input Clamp Current, dc (VI < 0 or VI > VDD
)
mA
mA
°C
°C
°C
°C
KV
Output Clamp Current, dc (VI < 0 or VI > VDD
)
IOK
TS
TA
TJ
-50
50
Storage Temperature Range (non-condensing)
Ambient Temperature Range, Under Bias
Junction Temperature
-65
150
-55
125
125
Lead Temperature (soldering, 10s)
Input Static Discharge Voltage Protection
260
2
3
10.29.02
ISO9001
T73227
27 MHz VCXO Clock Generator IC
October 2002
Table 3: Operating Conditions
PARAMETER
SYMBOL
CONDITIONS/DESCRIPTION
MIN.
TYP.
MAX.
UNITS
Core Supply Voltage (VDD
)
VDD
VIN
3.15
0
3.3
3.45
VDD
70
V
V
VCXO Control Voltage, VIN
Ambient Operating Temperature Range
Crystal Resonator Frequency
Crystal Load Capacitance
TA
0
°C
fXTAL
CL(xtal)
Fundamental Mode
AT cut
20
27
20
30
MHz
pF
Table 4: DC Electrical Specifications
Unless otherwise stated, VDD = 3.15V to 3.45V , no load on any output, and ambient temperature range TA = 0°C to 70°C.
PARAMETER
SYMBOL
CONDITIONS/DESCRIPTION
MIN.
TYP.
MAX.
UNITS
Overall
Supply Current, Dynamic, with no load
Output High Voltage
IDD
VOH
VOL
fXTAL = 27MHz
25
mA
V
IOH = -12mA
IOL = 12mA
2.4
Output Low Voltage
0.4
V
Voltage Controlled Crystal Oscillator - VDD=3.3V
As seen by a crystal connected to XIN and
XOUT (@ VXTUNE = 1.65V)
Crystal Loading Capacitance
CL(xtal)
CO/C1
20
pF
Crystal Gamma
240
50
fXTAL = 27MHz; CL(xtal) = 20pF; gamma = 240
VCXO Tuning Range
VCXO Tuning Characteristic
Crystal ESR
250
75
ppm
ppm/V
Ω
Note: positive ∆F for positive ∆V
Table 5: AC Timing Specifications
Unless otherwise stated, VDD = 3.15V to 3.45V, no load on any output, and ambient temperature range TA = 0°C to 70°C. Parameters denoted with an asterisk ( * ) represent nominal characterization
data and are not production tested to any specific limits.
PARAMETER
Clock Output (CLK)
SYMBOL
CONDITIONS/DESCRIPTION
MIN.
TYP.
MAX.
UNITS
Ratio of high pulse width (as measured from rising
edge to next falling edge at VDD/2) to one clock period
Duty Cycle *
40
60
%
From rising edge to next rising edge at VDD/2, CL =
10pF
Jitter, Period (peak-peak) *
150
ps
tj(∆P)
Rise Time *
Fall Time *
tr
tf
Measured 0.8V to 2.0V, CL = 10pF
Measured 2.0V to 0.8V; CL = 10pF
1.5
1.5
ns
ns
4
10.29.02
ISO9001
T73227
27 MHz VCXO Clock Generator IC
October 2002
Phase Noise vs. Frequency Offset
- 50
- 70
- 90
- 110
- 130
- 150
100
1K
10K
100K
1M
Frequency Offset from 27MHz
6.0 Ordering Information
ORDERING PART
PACKAGE TYPE
NUMBER
SHIPPING
CONFIGURATION
T73227-S08
T73227-S08-TNR
T73227-M08
Tubes
8-pin SOIC
8-pin SOIC
8-pin MSOP
8-pin MSOP
DIE
Tape and Reel
Tubes
T73227-M08-TNR
T73227-DIE
Tape and Reel
Waffle-Pack
TLSI reserves the right to make changes to its products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify,
before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgment, includ-
ing those pertaining to warranty, patent infringement, and limitation of liability.
TLSI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TLSI’s standard warranty. Testing and other quality control techniques
are utilized to the extent TLSI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government
requirements.
Customers are responsible for their applications using TLSI devices.
Information furnished by TLSI is believed to be accurate and reliable. However, no responsibility is assumed by TLSI for its use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or otherwise under any patent rights of TLSI.
TLSI and Silicon Driven are trademarks of TLSI, Inc. All other trademarks are the property of their respective owners.
TLSI Incorporated, 770 Park Avenue, Huntington NY 11743 • (631) 755-7005 • Fax 631-755-7626 • www.tlsi.com
5
10.29.02
ISO9001
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