The SY89423V device consists of two identical, low

jitter, digital Phase Locked Loops based on Micrel-Synergy's
differential PLL technology. Each PLL is capable of
operating in the 30MHz to 560MHz reference input
frequency range, and is independent of the other, and is
configurable separately. The PLLs can be configured to be
matched in all regards, or can be configured so that PLLB
is used as a frequency doubler, while PLLA is used to
regenerate the undoubled frequency. Each PLL is capable
of operating up to 2000MHz with the HFIN input and an
external VCO.

Two reference inputs (RINX and RINX), two feedback

inputs (FINX and FINX), two high frequency inputs (HFINX
and HFINX), two filter pins (F1X and F2X), two normal
outputs (FOUTX and FOUTX), and two high frequency
outputs (HFOUTX and HFOUTX) are provided for each of
the two PLLs. The reference, feedback, and high frequency
inputs can be used as either differential or single-ended
inputs. External reference voltage generators are required
for single-ended drive.

Feedback for the loops is realized by connecting FOUTX,

FOUTX to FINX, FINX by means of external circuitry. This
allows the user the flexibility of inserting additional circuitry
off-chip in the feedback paths, such as an additional
divider. Pulldown resistors are required for the FOUTX and
FOUTX pins, and for the HFOUTX and HFOUTX pins.

Use of a phase-frequency detector in each PLL results

in excellent locking and tracking characteristics. Error
correction voltages are generated by the detector if either
phase or frequency deviations occur. The VCO in each PLL
has a frequency range covering more than a 2:1 ratio from
480MHz to 1120MHz.

Select pins S1A, S2A, S1B, S2B, and S3B are used to

program the N dividers for optimum VCO operation, in
other words with the VCO operating in the center of its
range. When both S3B and S5B are low, PLLB is identical
to PLLA. When S5B is high, the 2X frequency multiplication
option is enabled. Select pins S3A and S4B enable the HF
inputs for PLLA and PLLB respectively, which allows the
use of an external VCO in either PLL. All the select pins are
TTL inputs.

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

Frequency doubler mode

Low jitter differential design

PECL differential outputs

External loop filter optimizes performance/cost

Available in 44-pin PLCC package

DESCRIPTION

ClockWorksTM

SY89423V

APPLICATIONS

Workstations

Advanced communications

High-performance computing

5V/3.3V DUAL
HIGH-PERFORMANCE
PHASE LOCKED LOOP

PIN CONFIGURATION

TOP VIEW

PLCC

J44-1

43 42 41

18 19 20 21 22

24 25 26

27 28

HFOUTA

S1A

S2A

F1A

F2A

S3A

S5B

HFINA

HFOUTB

S1B

S2B

F1B

F2B

S3B

S4B

HFINB

CCOA

FOUTA

FOUTB

CCOB

FINA

RINA

RINB

FINB

Rev.: G

Amendment: /0

Issue Date:

May 2000

ClockWorksTM

SY89423V

Micrel

Pin

Function

I/O

F1A

Filter Pin 1A

I/O

F2A

Filter Pin 2A

I/O

RINA

Inverted Reference Input A

RINA

Reference Input A

FINA

Feedback Input A

FINA

Inverted Feedback Input A

HFINA

High Frequency Input A

HFINA

Inverted High Frequency Input A

FOUTA

Frequency Output A

FOUTA

Inverted Frequency Output A

HFOUTA

High Frequency Output A

HFOUTA

Inverted High Frequency Output A

F1B

Filter Pin 1B

I/O

F2B

Filter Pin 2B

I/O

RINB

Reference Input B

RINB

Inverted Reference Input B

FINB

Feedback Input B

FINB

Inverted Feedback Input B

HFINB

High Frequency Input B

HFINB

Inverted High Frequency Input B

FOUTB

Frequency Output B

FOUTB

Inverted Frequency Output B

HFOUTB

High Frequency Output B

HFOUTB

Inverted Frequency Output B

CCOA

Output V

CCOB

Output V

(0V)

S1A

Select Input 1A (TTL)

S2A

Select Input 2A (TTL)

S3A

Select Input 3A (TTL)

S1B

Select Input 1B (TTL)

S2B

Select Input 2B (TTL)

S3B

Select Input 3B (TTL)

S4B

Select Input 4B (TTL)

S5B

Select Input 5B (TTL)

RINA, RINA, RINB, RINB

Reference frequency inputs for loop A and B. These are
differential signal pairs and may be driven differentially or
single-ended.

FINA, FINA, FINB, FINB

Feedback frequency inputs for loop A and B. These are
differential signal pairs and may be driven differentially or
single-ended.

HFINA, HFINA, HFINB, HFINB

High frequency feedback inputs. Differential drive is
recommended.

F1A, F2A, F1B, F2B

These pins are connection points for the loop filters, which are
to be provided off-chip. F1X is the high impedance side, F2X
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.

FOUTA, FOUTA, FOUTB, FOUTB

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.

HFOUTA, HFOUTA, HFOUTB, HFOUTB

High frequency outputs. These are differential, positive
referenced, emitter-follower signals and must be terminated
off-chip. Termination in 50 ohms is recommended.

S1A, S2A, S3A, S1B, S2B, S3B, S4B, S5B

These inputs are used to select the configuration for PLLA and
PLLB. See the Frequency Selection Table for details of the
logic.

This is the positive supply for the chip. It should be decoupled
and present a low impedance in order to assure low-jitter
operation.

CCOA

, V

CCOB

These are the positive supplies for the output buffers. They are
constrained to be equal to or less than the value of V

This pin is the negative supply for the chip and is normally
connected to ground (0V).

PIN NAMES

PIN DESCRIPTION

ClockWorksTM

SY89423V

Micrel

FREQUENCY SELECTION TABLE

S3A

S2A

S1A

FOUTA (MHz)

HFOUTA (MHz)

240 � 560

480 � 1120

120 � 280

480 � 1120

60 � 140

480 � 1120

30 � 70

480 � 1120

HFINA divide by 4

HFINA divide by 2

HFINA divide by 8

HFINA divide by 2

HFINA divide by 16

HFINA divide by 2

HFINA divide by 32

HFINA divide by 2

PLLA

PLLB

S4B

S3B

S2B

S1B

FOUTB (MHz)

HFOUTB (MHz)

240 � 560

480 � 1120

120 � 280

480 � 1120

60 � 140

480 � 1120

30 � 70

480 � 1120

48 � 112

480 � 1120

40 � 93.3

480 � 1120

24 � 56

480 � 1120

HFINB divide by 4

HFINB divide by 2

HFINB divide by 8

HFINB divide by 2

HFINB divide by 16

HFINB divide by 2

HFINB divide by 32

HFINB divide by 2

HFINB divide by 20

HFINB divide by 2

HFINB divide by 24

HFINB divide by 2

HFINB divide by 40

HFINB divide by 2

Maximum Feedback

S5B

Divide-by-P

Frequency (MHz)

P = 1

560

P = 2

1120

ClockWorksTM

SY89423V

Micrel

ABSOLUTE MAXIMUM RATINGS

(1)

Symbol

Parameter

Value

Unit

Power Supply Voltage

�0.5 to +7.0

TTL Input Voltage

(2)

�0.5 to 6.0

TTL Input Current

(2)

�30 to +5.0

OUT

ECL Output Current

�Continuous

�Surge

100

store

Storage Temperature

�65 to +150

�

Operating Temperature

(3)

0 to +85

�

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 temperature range.

Symbol

Parameter

Min.

Typ.

Max.

Unit

Condition

Output HIGH Voltage

� 1.025

� 0.780

Output LOW Voltage

� 1.810

� 1.520

Input HIGH Voltage

� 1.165

� 0.780

Input LOW Voltage

� 1.810

� 1.475

PECL DC ELECTRICAL CHARACTERISTICS

= V

CCOA

= V

CCOB

= 3.3V or 5.0V

�

Symbol

Parameter

Min.

Typ.

Max.

Unit

Condition

Power Supply Voltage

4.75

5.25

CCO

Power Supply Current (V

)

200

CCO

Power Supply Current (V

CCO

)

PECL outputs are open

5V DC ELECTRICAL CHARACTERISTICS

= V

CCOA

= V

CCOB

= 5.0V

�

Symbol

Parameter

Min.

Typ.

Max.

Unit

Condition

Power Supply Voltage

3.135

3.465

CCO

Power Supply Current (V

)

200

CCO

Power Supply Current (V

CCO

)

PECL outputs are open

3.3V DC ELECTRICAL CHARACTERISTICS

= V

CCOA

= V

CCOB

= 3.3V

�

Электронный компонент: SY89423VJC