ICS8440258AK-46LF IDT, Integrated Device Technology Inc, ICS8440258AK-46LF Datasheet - Page 8

• Manufacturer Part Number: ICS8440258AK-46LF
• Description: IC SYNTHESIZER 8OUTPUT 32-VFQFPN
• Manufacturer: IDT, Integrated Device Technology Inc
• Series: HiPerClockS™, FemtoClock®r
• Type: Frequency Synthesizerr

Specifications of ICS8440258AK-46LF

• Pll: Yes with Bypass
• Input: LVCMOS, LVTTL, Crystal
• Output: LVCMOS, LVDS, LVTTL
• Number Of Circuits: 1
• Ratio - Input:output: 2:8
• Differential - Input:output: No/Yes
• Frequency - Max: 125MHz
• Divider/multiplier: Yes/No
• Voltage - Supply: 2.375 V ~ 2.625 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 32-VFQFN
• Frequency-max: 125MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 8440258AK-46LF

As in any high speed analog circuitry, the power supply pins
are vulnerable to random noise. The ICS8440258-46 provides
separate power supplies to isolate any high switching noise
from the outputs to the internal PLL. V
should be individually connected to the power supply plane
through vias, and bypass capacitors should be used for each
pin. To achieve optimum jitter performance, power supply iso-
lation is required. Figure 1 illustrates how a 10Ω resistor along
with a 10µF and a 0.01μF bypass capacitor should be con-
nected to each V
C
The ICS8440258-46 has been characterized with 18pF parallel
resonant crystals. The capacitor values shown in Figure 2 below
IDT
P
RYSTAL
OWER
ICS8440258-46
FEMTOCLOCK™ CRYSTAL/LVCMOS-TO-LVDS/ LVCMOS FREQUENCY SYNTHESIZER
™
/ ICS
™
S
LVDS/LVCMOS FREQUENCY SYNTHESIZER
I
UPPLY
NPUT
DDA
I
F
NTERFACE
ILTERING
.
T
ECHNIQUES
18pF Parallel Cry stal
DD
, V
A
DDA
X1
PPLICATION
, V
F
IGURE
DDO1
and V
2. C
DDO2
RYSTAL
C1
22p
C2
22p
8
I
NFORMATION
were determined using a 25MHz, 18pF parallel resonant crystal
and were chosen to minimize the ppm error.
I
XTAL_IN
XTAL_OUT
NPU
t I
NTERFACE
F
IGURE
ICS84332
1. P
ICS8440258AK-46 REV B JANUARY 15, 2008
V
V
DDA
DD
OWER
.01μF
.01μF
S
UPPLY
2.5V
F
10Ω
10μF
ILTERING
PRELIMINARY