sy89420v Micrel Semiconductor, sy89420v Datasheet - Page 3

• Manufacturer Part Number: sy89420v
• Description: 5v/3.3v Dual Phase Locked Loop
• Manufacturer: Micrel Semiconductor

Micrel
LOOP FILTER COMPONENT SELECTION
PIN NAMES
C
R
Pin
F1A
F2A
RINA
RINA
FINA
FINA
FOUTA
FOUTA
F1B
F2B
RINB
RINB
FINB
FINB
FOUTB
FOUTB
V
V
V
V
V
V
S1A
S2A
S1B
S2B
S3B
S4B
CC
CCOA
CCOB
EE
BB
TH
=
=
F1X
Filter Pin 1A
Filter Pin 2A
Reference Input A
Inverted Reference Input A
Feedback Input A
Inverted Feedback Input A
Frequency Output A
Inverted Frequency Output A
Filter Pin 1B
Filter Pin 2B
Reference Input B
Inverted Reference Input B
Feedback Input B
Inverted Feedback Input B
Frequency Output B
Inverted Frequency Output B
V
Output A V
Output B V
V
PECL Threshold Voltage
TTL Threshold Voltage
Select Input 1A (TTL)
Select Input 2A (TTL)
Select Input 1B (TTL)
Select Input 2B (TTL)
Select Input 3B (TTL)
Select Input 4B (TTL)
1.0 F 10% (X7R dielectric)
560
CC
EE
(0V)
R
10%
CC
CC
Function
C
F2X
I/O
I/O
I/O
I/O
I/O
—
—
—
—
O
O
O
O
O
O
I
I
I
I
I
I
I
I
I
I
I
I
I
I
3
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.
V
These are the reference voltages for use as bias for the
frequency inputs. The references are generated on-chip. V
is PECL compatible, while V
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.
S1A, S2A, S1B, S2B, S3B, S4B
These inputs are used to select the configuration for PLLA and
PLLB. They are compatible with standard TTL signal levels.
See the Frequency Selection Table for details of the logic.
V
This is the positive supply for the entire chip excluding output
buffers. It should be decoupled and present a very low
impedance in order to assure low-jitter operation.
V
These are the positive supplies for the output buffers. They
are constrained to be equal to the value of V
be decoupled and present a very low impedance in order to
assure low-jitter operation.
V
This pin is the negative supply for the chip and is normally
connected to ground (0V).
BB
CC
CCOA
EE
PIN DESCRIPTION
, V
TH
, V
CCOB
TH
is TTL compatible.
CC
. They should
ClockWorks™
SY89420V
BB