LOW SKEW, 1:6 CRYSTAL-TO-
LVCMOS/LVTTL FANOUT BUFFER
ICS83905
GENERAL DESCRIPTION
The ICS83905 is a low skew, 1-to-6 LVCMOS / LVTTL
ICS Fanout Buffer and a member of the HiPerClockS™
HiPerClockS™ family of High Performance Clock Solutions from IDT.
The low impedance LVCMOS/LVTTL outputs are de-
signed to drive 50Ω series or parallel terminated
transmission lines. The effective fanout can be increased from 6
to 12 by utilizing the ability of the outputs to drive two series
terminated lines.
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The ICS83905 is characterized at full 3.3V, 2.5V, and 1.8V,
mixed 3.3V/2.5V, 3.3V/1.8V and 2.5V/1.8V output operating
supply mode. Guaranteed output and part-to-part skew char-
acteristics along with the 1.8V output capabilities makes the
ICS83905 ideal for high performance, single ended applica-
tions that also require a limited output voltage.
FEATURES
• Six LVCMOS / LVTTL outputs
• Outputs able to drive 12 series terminated lines
• Crystal oscillator interface
• Crystal input frequency range: 10MHz to 40MHz
• Output skew: 80ps (maximum)
• RMS phase jitter @ 25MHz, (100Hz - 1MHz):
0.26ps (typical) (VDD = VDDO = 2.5V)
Phase noise:
Offset
Noise Power
100Hz ............. -129.7 dBc/Hz
1kHz ............. -144.4 dBc/Hz
10kHz ............. -147.3 dBc/Hz
100kHz ............. -157.3 dBc/Hz
PIN ASSIGNMENTS
ICS83905
20-Lead VFQFN
4mm x 4mm x 0.9mm
body package
K Package
Top View
GND
GND
BCLK0
VDDO
BCLK1
20 19 18 17 16
1 15
2 14
3 13
4 12
5 11
6 7 8 9 10
BCLK5
VDDO
BCLK4
GND
GND
• 5V tolerant enable inputs
• Synchronous output enables
• Operating power supply modes:
Full 3.3V, 2.5V and 1.8V,
mixed 3.3V core/2.5V output operating supply,
mixed 3.3V core/1.8V output operating supply,
mixed 2.5V core/1.8V output operating supply
• 0°C to 70°C ambient operating temperature
• Available in both standard (RoHS 5) and lead-free (RoHS 6)
packages
BLOCK DIAGRAM
XTAL_OUT
ENABLE 2
GND
BCLK0
VDDo
BCLK1
GND
BCLK2
1
2
3
4
5
6
7
8
16 XTAL_IN
15 ENABLE 1
14 BCLK5
13 VDDO
12 BCLK4
11 GND
10 BCLK3
9 VDD
ICS83905
16-Lead SOIC
3.9mm x 9.9mm x 1.38mm body
package
M Pacakge
Top View
16-Lead TSSOP
4.4mm x 5.0mm x 0.92mm body
package
G Pacakge
Top View
XTAL_IN
XTAL_OUT
ENABLE 1
ENABLE 2
SYNCHRONIZE
SYNCHRONIZE
BCLK0
BCLK1
BCLK2
BCLK3
BCLK4
BCLK5
IDT™ / ICS™ LVCMOS/LVTTL FANOUT BUFFER
1
ICS83905AM REV. B JULY 9, 2007
