sy89421v Micrel Semiconductor, sy89421v Datasheet - Page 3

• Manufacturer Part Number: sy89421v
• Description: Sy89421v High Performance Phase Locked Loop
• Manufacturer: Micrel Semiconductor

Micrel
PIN NAMES
Pin
F1
F2
RIN
RIN
FIN
FIN
HFIN
HFIN
HFOUT
HFOUT
FOUT
FOUT
V
V
V
S1
S2
S3
S4
S5
CC
CCO
EE
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
Output V
V
Select Input 1 (TTL)
Select Input 2 (TTL)
Select Input 3 (TTL)
Select Input 4 (TTL)
Select Input 5 (TTL)
CC
EE
(0V)
CC
Function
I/O
I/O
I/O
—
—
—
O
O
O
O
I
I
I
I
I
I
I
I
I
I
I
3
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
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
This is the positive supply for the output buffer. It is constrained
to be equal to or less than the value of V
decoupled and should present a very low impedance for low-
jitter.
V
This pin is the negative supply for the chip and is normally
connected to ground (0V).
CC
CCO
EE
PIN DESCRIPTION
CC
. It should be
ClockWorks™
SY89421V