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5V/3.3V
HIGH-PERFORMANCE
PHASE LOCKED LOOP
ClockWorks™
SY89421V
FEATURES
■ 3.3V and 5V power supply options
■ 1.12GHz maximum VCO frequency
■ 30MHz to 560MHz reference input operating
frequency
■ External 2.0GHz VCO capability
■ Low jitter differential design
■ Frequency doubler mode
■ PECL Differential output
■ External loop filter optimizes performance/cost
■ Available in 20-pin SOIC package
APPLICATIONS
■ Workstations
■ Advanced communications
■ High-performance computing
PIN CONFIGURATION
S1
1
20
S2
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.
FIN
FIN
V
F1
F2
S5
HFIN
HFIN
S4
2
3
EE
4
5
6
7
8
9
10
TOP VIEW
SOIC
Z20-1
19
18
17
16
15
14
13
12
11
RIN
RIN
S3
V
CC
FOUT
FOUT
V
CCO
HFOUT
HFOUT
Rev.: F Amendment: /0
1
Issue Date: May 2000
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Micrel
BLOCK DIAGRAM
ClockWorks™
SY89421V
F1 F2
RIN
RIN
FIN
FIN
D
PHASE-FREQUENCY
DETECTOR
÷ P
(1, 2)
S5
LOOP
FILTER
VCO
S4
(1,2,4,8,10,12,16,20)
÷ 2
01
MUX
÷ N
HFIN
HFIN
HFOUT
HFOUT
S1
S2
S3
FOUT
FOUT
LOOP FILTER COMPONENT SELECTION
F1 F2
C = 1.0µF ±10% (X7R dielectric)
R = 560Ω ±10%
R
2
C
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Micrel
PIN NAMES PIN DESCRIPTION
ClockWorks™
SY89421V
Pin Function I/O
F1 Filter Pin 1 I/O
F2 Filter Pin 2 I/O
RIN Reference Input I
RIN Inverted Reference Input I
FIN Feedback Input I
FIN Inverted Feeback Input I
HFIN High Frequency Input I
HFIN Inverted High Frequency Input I
HFOUT High Frequency Output O
HFOUT Inverted High Frequency Output O
FOUT Frequency Output O
FOUT Inverted Frequency Output O
VCC VCC —
VCCO Output VCC —
VEE VEE (0V) —
S1 Select Input 1 (TTL) I
S2 Select Input 2 (TTL) I
S3 Select Input 3 (TTL) I
S4 Select Input 4 (TTL) I
S5 Select Input 5 (TTL) I
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.
VCC
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.
VCCO
This is the positive supply for the output buffer. It is constrained
to be equal to or less than the value of VCC. It should be
decoupled and should present a very low impedance for lowjitter.
VEE
This pin is the negative supply for the chip and is normally
connected to ground (0V).
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Micrel
FREQUENCY SELECTION TABLE
FOUT HFOUT
S4 S3 S2 S1 N Freq. Range MHz Freq. Range MHz
00002240 – 560 480 – 1120
00014120 – 280 480 – 1120
00108 60 – 140 480 – 1120
001116 30 – 70 480 – 1120
01001480 – 1120 480 – 1120
01011048 – 112 480 – 1120
01101240 – 93.3 480 – 1120
011120 20 – 56 480 – 1120
10002HFIN divide by 4 HFIN divide by 2
10014HFIN divide by 8 HFIN divide by 2
10108HFIN divide by 16 HFIN divide by 2
101116HFIN divide by 32 HFIN divide by 2
11001HFIN divide by 2 HFIN divide by 2
110110HFIN divide by 20 HFIN divide by 2
111012HFIN divide by 24 HFIN divide by 2
111120HFIN divide by 40 HFIN divide by 2
ClockWorks™
SY89421V
Maximum Feedback
S5 Divide-by-P Frequency (MHz)
0 P = 1 560
1 P = 2 1120
ABSOLUTE MAXIMUM RATINGS
(1)
Symbol Parameter Value Unit
VCC Power Supply Voltage –0.5 to +7.0 V
VI TTL Input Voltage
II TTL Input Current
OUT ECL Output Current mA
I
(2)
(2)
–0.5 to 6.0 V
–30 to +5.0 mA
— Continuous 50
— Surge 100
Tstore Storage Temperature –65 to +150 °C
A Operating Temperature Range
T
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.
(3)
0 to +85 °C
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Micrel
5V DC ELECTRICAL CHARACTERISTICS
VCC = VCCO = 5.0V ±5%
Symbol Parameter Min. Typ. Max. Unit Condition
VCC Power Supply Voltage 4.75 — 5.25 V VCC = VCCO
ICC Power Supply Current (VCC)——100mA
CCO Power Supply Current (VCCO) — — 28 mA PECL outputs are open
I
3.3V DC ELECTRICAL CHARACTERISTICS
VCC = VCCO = 3.3V ±5%
Symbol Parameter Min. Typ. Max. Unit Condition
VCC Power Supply Voltage 3.135 — 3.465 V VCC = VCCO
ICC Power Supply Current (VCC)——100mA
I
CCO Power Supply Current (VCCO) — — 28 mA PECL outputs are open
ClockWorks™
SY89421V
PECL DC ELECTRICAL CHARACTERISTICS
VCC = VCCO = 3.3V or 5.0V ±5%
Symbol Parameter Min. Typ. Max. Unit Condition
VOH Output HIGH Voltage VCC – 1.025 — VCC – 0.780 V
VOL Output LOW Voltage VCC – 1.810 — VCC – 1.520 V
VIH Input HIGH Voltage VCC – 1.165 — VCC – 0.780 V
IL Input LOW Voltage VCC – 1.810 — VCC – 1.475 V
V
TTL DC ELECTRICAL CHARACTERISTICS
VCC = VCCO = 3.3V or 5.0V ±5%
Symbol Parameter Min. Typ. Max. Unit Condition
VIH Input HIGH Voltage 2.0 — — V
VIL Input LOW Voltage — — 0.8 V
IH Input HIGH Current — — 20 µAVIN = 2.7V
I
100 VIN = VCC
IIL Input LOW Current — — –0.3 mA VIN = 0.5V
V
IK Input Clamp Voltage — — – 1.2 V IIN = –12mA
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Micrel
AC ELECTRICAL CHARACTERISTICS
VCC = VCCO = 3.3V or 5.0V ±5%
Symbol Parameter Min. Typ. Max. Unit Condition
∆Τ Output Period Jitter — 10 15 ps rms
PPW Output Duty Cycle 45 50 55 %
tr Output Rise/Fall Time — 300 550 ps —
tf (20% to 80%) — 300 550
RIN Reference Frequency Input — — 560 MHz
FIN Feedback Frequency Input — — 560 MHz S5 = 0
— — 1120 MHz S5 = 1
HFIN High Frequency Input — — 2000 MHz
HFOUT High Frequency Output — — 1120 MHz
FOUT Frequency Output — — 1120 MHz
ClockWorks™
SY89421V
PRODUCT ORDERING CODE
Odering Package Operating
Code Type Range
SY89421VZC Z20-1 Commercial
SY89421VZCTR Z20-1 Commercial
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Micrel
20 LEAD SOIC .300" WIDE (Z20-1)
ClockWorks™
SY89421V
Rev. 03
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Micrel
ClockWorks™
SY89421V
MICREL-SYNERGY 3250 SCOTT BOULEVARD SANTA CLARA CA 95054 USA
TEL + 1 (408) 980-9191 FAX + 1 (408) 914-7878 WEB http://www.micrel.com
This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or
other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc.
© 2000 Micrel Incorporated
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