ICS844202AKI-245LFT IDT, Integrated Device Technology Inc, ICS844202AKI-245LFT Datasheet - Page 6

• Manufacturer Part Number: ICS844202AKI-245LFT
• Description: IC CLOCK GEN SRL SCSI 32-VFQFPN
• Manufacturer: IDT, Integrated Device Technology Inc
• Series: HiPerClockS™r
• Type: Clock/Frequency Synthesizerr

Specifications of ICS844202AKI-245LFT

• Input: LVCMOS, LVTTL
• Output: LVDS
• Frequency - Max: 250MHz
• Voltage - Supply: 3.135 V ~ 3.465 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 32-VFQFN
• Frequency-max: 250MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 844202AKI-245LFT

R
I
LVCMOS C
All control pins have internal pull-ups or pull-downs; additional
resistance is not required but can be added for additional
protection. A 1k
IDT
C
The ICS844204-245 has been characterized with 18pF parallel
resonant crystals. The capacitor values shown in Figure 2 below
As in any high speed analog circuitry, the power supply pins
are vulnerable to random noise. The ICS844204-245 provides
separate power supplies to isolate any high switching
noise from the outputs to the internal PLL. V
V
plane through vias, and bypass capacitors should be
used for each pin. To achieve optimum jitter performance, power
supply isolation is required. Figure 1 illustrates how
a 10
capacitor should be connected to each V
P
NPUTS
DDO
ECOMMENDATIONS FOR
RYSTAL
ICS844202-245
CRYSTAL-TO-LVDS PCI EXPRESS™ CLOCK SYNTHESIZER W/SPREAD SPECTRUM
OWER
™
/ ICS
should be individually connected to the power supply
:
resistor along with a 10µF and a .01 F bypass
™
S
LVDS PCI EXPRESS™ CLOCK SYNTHESIZER
I
UPPLY
NPUT
ONTROL
I
resistor can be used.
F
NTERFACE
P
INS
ILTERING
U
NUSED
T
ECHNIQUES
18pF Parallel Crystal
I
NPUT AND
DDA
A
X1
.
PPLICATION
F
IGURE
O
DD,
UTPUT
V
2. C
DDA
P
and
RYSTAL
INS
C1
27p
C2
27p
6
I
I
NFORMATION
O
LVDS O
All unused LVDS output pairs can be either left floating or
terminated with 100 across. If they are left floating, there should
be no trace attached.
were determined using a 25MHz, 18pF parallel resonant crystal
and were chosen to minimize the ppm error.
NPU
XTAL_OUT
XTAL_IN
UTPUTS
t I
NTERFACE
UTPUTS
:
F
IGURE
1. P
V
V
DDA
DD
ICS844202BK-245 REV. A JULY 9, 2007
OWER
.01 F
.01 F
S
UPPLY
3.3V
10
10 F
F
ILTERING
PRELIMINARY