5V/3.3V
HIGH-PERFORMANCE
PHASE LOCKED LOOP
FEATURES
s
3.3V and 5V power supply options
s
1.12GHz maximum VCO frequency
s
30MHz to 560MHz reference input operating
frequency
s
External 2.0GHz VCO capability
s
Low jitter differential design
s
Frequency doubler mode
s
PECL Differential output
s
External loop filter optimizes performance/cost
s
Available in 20-pin SOIC package
ClockWorks™
SY89421V
FINAL
DESCRIPTION
The SY89421V is a digital Phase Locked Loop based on
Micrel-Synergy's differential PLL technology. It is capable
of operating in the 30MHz to 560MHz reference input
frequency range, and up to 2000MHz with the HFIN input
and an external VCO. Use of a phase-frequency detector
results in excellent PLL locking and tracking characteristics.
Error correction voltages are generated by the detector if
either phase or frequency deviations occur. The VCO has
a frequency range covering more than a 2:1 ratio from
480MHz to 1120MHz.
Feedback for the loop is realized by connecting FOUT,
FOUT to FIN, FIN by means of external circuitry. This
allows the flexibility of inserting additional circuitry off-chip
in the feedback paths, such as an additional divider and/or
buffer. Pulldown resistors are required for the FOUT and
FOUT pins. High frequency inputs HFIN, HFIN and
corresponding outputs HFOUT, HFOUT are featured for
use with external components such as an active loop filter
and a high frequency VCO.
Select pins S1 and S2 are used to program the N divider
for optimum VCO operation, in other words with the VCO in
the center of its range. Select pin S3 allows bypassing the
N divider enabling the PLL to output the VCO directly.
Select pin S4 is used to select off-chip or on-chip VCO.
Select pin S5 enables the divide-by-two prescaler, which is
useful in frequency doubling applications. All Select pins
are TTL compatible.
APPLICATIONS
s
Workstations
s
Advanced communications
s
High-performance computing
PIN CONFIGURATION
S1
FIN
FIN
V
EE
F1
F2
S5
HFIN
HFIN
1
2
3
4
5
6
7
8
9
20
19
18
17
S2
RIN
RIN
S3
V
CC
FOUT
FOUT
V
CCO
HFOUT
HFOUT
TOP VIEW
SOIC
Z20-1
16
15
14
13
12
11
S4 10
Rev.: F
Amendment: /0
1
Issue Date: May 2000
Micrel
ClockWorks™
SY89421V
BLOCK DIAGRAM
F1
F2
HFIN
HFIN
÷2
RIN
D
LOOP
FILTER
RIN
PHASE-FREQUENCY
DETECTOR
VCO
FIN
FIN
÷P
(1, 2)
S4
0
MUX
1
S5
HFOUT
HFOUT
÷N
(1,2,4,8,10,12,16,20)
S1
S2
S3
FOUT
FOUT
LOOP FILTER COMPONENT SELECTION
R
C
F1
F2
C
R
= 1.0µF
±10%
(X7R dielectric)
= 560Ω
±10%
2
Micrel
ClockWorks™
SY89421V
PIN NAMES
Pin
F1
F2
RIN
RIN
FIN
FIN
HFIN
HFIN
HFOUT
HFOUT
FOUT
FOUT
V
CC
V
CCO
V
EE
S1
S2
S3
S4
S5
Filter Pin 1
Filter Pin 2
Reference Input
Inverted Reference Input
Feedback Input
Inverted Feeback Input
High Frequency Input
Inverted High Frequency Input
High Frequency Output
Inverted High Frequency Output
Frequency Output
Inverted Frequency Output
V
CC
Output V
CC
V
EE
(0V)
Select Input 1 (TTL)
Select Input 2 (TTL)
Select Input 3 (TTL)
Select Input 4 (TTL)
Select Input 5 (TTL)
Function
I/O
I/O
I/O
I
I
I
I
I
I
O
O
O
O
—
—
—
I
I
I
I
I
PIN DESCRIPTION
RIN, RIN
Reference frequency inputs. These are differential signal
pairs and may be driven differentially or single-ended.
FIN, FIN
Feedback frequency inputs. These are a differential signal
pair and may be driven differentially or single-ended.
HFIN, HFIN
High frequency feedback inputs. These are a differential
signal pair. Differential drive is recommended.
F1, F2
These pins are connection points for the loop filter, which is to
be provided off-chip. F1 is the high impedance side, F2 is the
reference side. The loop filter should be a first order, low pass
with a DC block. The difference voltage on these pins will be
a dc level, which is controlled by the loop feedback and
determined by the required VCO frequency.
FOUT, FOUT
Frequency outputs for the loops. These are differential, positive
referenced, emitter-follower signals and must be terminated
off chip. Termination in 50 ohms is recommended.
HFOUT, HFOUT
High frequency output. These are a differential signal pair.
Termination in 50 ohms is recommended.
S1, S2, S3, S4, S5
These are the frequency select inputs, and are used to
configure the PLL. They are compatible with standard TTL
signal levels. See the Frequency Selection Table for details
of the logic.
V
CC
This is the positive supply for the chip. It should be decoupled
and should present a very low impedance in order to assure
low-jitter operation.
V
CCO
This is the positive supply for the output buffer. It is constrained
to be equal to or less than the value of V
CC
. It should be
decoupled and should present a very low impedance for low-
jitter.
V
EE
This pin is the negative supply for the chip and is normally
connected to ground (0V).
3
Micrel
ClockWorks™
SY89421V
FREQUENCY SELECTION TABLE
FOUT
Freq. Range MHz
240 – 560
120 – 280
60 – 140
30 – 70
480 – 1120
48 – 112
40 – 93.3
20 – 56
HFIN divide by 4
HFIN divide by 8
HFIN divide by 16
HFIN divide by 32
HFIN divide by 2
HFIN divide by 20
HFIN divide by 24
HFIN divide by 40
HFOUT
Freq. Range MHz
480 – 1120
480 – 1120
480 – 1120
480 – 1120
480 – 1120
480 – 1120
480 – 1120
480 – 1120
HFIN divide by 2
HFIN divide by 2
HFIN divide by 2
HFIN divide by 2
HFIN divide by 2
HFIN divide by 2
HFIN divide by 2
HFIN divide by 2
S4
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
S3
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
S2
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
S1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
N
2
4
8
16
1
10
12
20
2
4
8
16
1
10
12
20
S5
0
1
Divide-by-P
P= 1
P= 2
Maximum Feedback
Frequency (MHz)
560
1120
ABSOLUTE MAXIMUM RATINGS
(1)
Symbol
V
CC
V
I
I
I
I
OUT
Parameter
Power Supply Voltage
TTL Input Voltage
(2)
TTL Input Current
(2)
ECL Output Current
— Continuous
— Surge
Storage Temperature
Operating Temperature Range
(3)
Value
–0.5 to +7.0
–0.5 to 6.0
–30 to +5.0
50
100
–65 to +150
0 to +85
°C
°C
Unit
V
V
mA
mA
T
store
T
A
NOTES:
1. Permanent device damage may occur if ABSOLUTE MAXIMUM RATINGS are exceeded. This is a stress rating only and functional operation is not
implied at conditions other than those detailed in the operational sections of this data sheet. Exposure to ABSOLUTE MAXIMUM RATING conditions
for extended periods may affect device reliability.
2. Either voltage limit or current limit is sufficient to protect input.
3. All DC and AC electrical characteristics are specified over the operating termperature range.
4
Micrel
ClockWorks™
SY89421V
5V DC ELECTRICAL CHARACTERISTICS
V
CC
= V
CCO
= 5.0V
±5%
Symbol
V
CC
I
CC
I
CCO
Parameter
Power Supply Voltage
Power Supply Current (V
CC
)
Power Supply Current (V
CCO
)
Min.
4.75
—
—
Typ.
—
—
—
Max.
5.25
100
28
Unit
V
mA
mA
PECL outputs are open
Condition
V
CC
= V
CCO
3.3V DC ELECTRICAL CHARACTERISTICS
V
CC
= V
CCO
= 3.3V
±5%
Symbol
V
CC
I
CC
I
CCO
Parameter
Power Supply Voltage
Power Supply Current (V
CC
)
Power Supply Current (V
CCO
)
Min.
3.135
—
—
Typ.
—
—
—
Max.
3.465
100
28
Unit
V
mA
mA
PECL outputs are open
Condition
V
CC
= V
CCO
PECL DC ELECTRICAL CHARACTERISTICS
V
CC
= V
CCO
= 3.3V or 5.0V
±5%
Symbol
V
OH
V
OL
V
IH
V
IL
Parameter
Output HIGH Voltage
Output LOW Voltage
Input HIGH Voltage
Input LOW Voltage
Min.
V
CC
– 1.025
V
CC
– 1.810
V
CC
– 1.165
V
CC
– 1.810
Typ.
—
—
—
—
Max.
V
CC
– 0.780
V
CC
– 1.520
V
CC
– 0.780
V
CC
– 1.475
Unit
V
V
V
V
Condition
TTL DC ELECTRICAL CHARACTERISTICS
V
CC
= V
CCO
= 3.3V or 5.0V
±5%
Symbol
V
IH
V
IL
I
IH
I
IL
V
IK
Parameter
Input HIGH Voltage
Input LOW Voltage
Input HIGH Current
Input LOW Current
Input Clamp Voltage
Min.
2.0
—
—
—
—
Typ.
—
—
—
—
—
Max.
—
0.8
20
100
–0.3
– 1.2
Unit
V
V
µA
mA
V
V
IN
= 2.7V
V
IN
= V
CC
V
IN
= 0.5V
I
IN
= –12mA
Condition
5
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