LOW SKEW, 1-TO-16
LVCMOS/LVTTL CLOCK GENERATOR
87016 DATA SHEET
10 REVISION C 06/26/15
APPLICATION INFORMATION
FIGURE 1. SINGLE ENDED SIGNAL DRIVING DIFFERENTIAL INPUT
Figure 1 shows how the differential input can be wired to accept
single ended levels. The reference voltage V_REF = V
DD
/2 is
generated by the bias resistors R1, R2 and C1. This bias circuit
should be located as close as possible to the input pin. The ratio
WIRING THE DIFFERENTIAL INPUT TO ACCEPT SINGLE ENDED LEVELS
of R1 and R2 might need to be adjusted to position the V_REF
in the center of the input voltage swing. For example, if the input
clock swing is only 2.5V and V
DD
= 3.3V, V_REF should be 1.25V
and R2/R1 = 0.609.
INPUTS:
CLK INPUT:
For applications not requiring the use of a clock input, it can be
left fl oating. Though not required, but for additional protection, a
1kΩ resistor can be tied from the CLK input to ground.
CLK/nCLK I
NPUT:
For applications not requiring the use of the differential input,
both CLK and nCLK can be left fl oating. Though not required,
but for additional protection, a 1kΩ resistor can be tied from
CLK to ground.
LVCMOS C
ONTROL PINS:
All control pins have internal pull-ups or pull-downs; additional
resistance is not required but can be added for additional
protection. A 1kΩ resistor can be used.
RECOMMENDATIONS FOR UNUSED INPUT AND OUTPUT PINS
OUTPUTS:
LVCMOS OUTPUT:
All unused LVCMOS output can be left fl oating. We recommend
that there is no trace attached.
REVISION C 06/26/15
87016 DATA SHEET
11 LOW SKEW, 1-TO-16
LVCMOS/LVTTL CLOCK GENERATOR
FIGURE 2C. CLK/NCLK INPUT DRIVEN BY
3.3V LVPECL DRIVER
FIGURE 2B. CLK/NCLK INPUT DRIVEN BY
3.3V LVPECL DRIVER
FIGURE 2D. CLK/NCLK INPUT DRIVEN BY
3.3V LVDS DRIVER
3.3V
R1
50
R3
50
Zo = 50 Ohm
LVPECL
Zo = 50 Ohm
HiPerClockS
CLK
nCLK
3.3V
Input
R2
50
Zo = 50 Ohm
Input
HiPerClockS
CLK
nCLK
3.3V
R3
125
R2
84
Zo = 50 Ohm
3.3V
R4
125
LVPECL
R1
84
3.3V
DIFFERENTIAL CLOCK INPUT INTERFACE
The CLK /nCLK accepts LVDS, LVPECL, LVHSTL, SSTL, HCSL
and other differential signals. Both V
SWING
and V
OH
must meet
the V
PP
and V
CMR
input requirements. Figures 4A to 4E show
interface examples for the CLK/nCLK input driven by the most
common driver types. The input interfaces suggested here are
examples only. Please consult with the vendor of the driver
FIGURE 2A. CLK/NCLK INPUT DRIVEN BY
LVHSTL DRIVER
component to confi rm the driver termination requirements. For
example in Figure 2A, the input termination applies for LVHSTL
drivers. If you are using an LVHSTL driver from another
vendor, use their termination recommendation.
1.8V
R2
50
Input
LVHSTL Driver
ICS
HiPerClockS
R1
50
LVHSTL
3.3V
Zo = 50 Ohm
Zo = 50 Ohm
HiPerClockS
CLK
nCLK
FIGURE 2E. CLK/NCLK INPUT DRIVEN BY
3.3V LVPECL DRIVER WITH AC COUPLE
Zo = 50 Ohm
R3
125
HiPerClockS
CLK
nCLK
3.3V
R5
100 - 200
3.3V
R2
84
3.3V
R6
100 - 200
Input
R5,R6 locate near the driver pin.
Zo = 50 Ohm
R1
84
R4
125
C2
LVPECL
C1
Zo = 50 Ohm
R1
100
3.3V
LVDS_Driv er
Zo = 50 Ohm
Receiv er
CLK
nCLK
3.3V
LOW SKEW, 1-TO-16
LVCMOS/LVTTL CLOCK GENERATOR
87016 DATA SHEET
12 REVISION C 06/26/15
SCHEMATIC EXAMPLE
Figure 3 shows an application schematic example of the 87016.
This schematic provides examples of input and output handling.
The differential CLK1/nCLK1 input can accept various types of
differential signal. This example shows the 87016 input driven by
a 3.3V LVPECL driver. Additional examples for the input driven
by other types of drivers are shown in the application section of
this data sheet. The single ended input CLK0 is driven by a 7Ω
FIGURE 3. APPLICATION SCHEMATIC EXAMPLE
Zo = 50 Ohm
C5
0.1u
RD1
SPARE
LVPECL
VDD
(U1-48)
To Logic
Input
pins
3.3V
3.3V
VCC
C10
0.1u
Logic Input Pin Examples
C1
0.1u
R4
50
C4
0.1u
Ro=7 Ohm
R2 ~43
Zo = 50
C9
0.1u
R1 ~43
C7
0.1u
LVCMOS
(U1-22)
RU1
1K
VDD
VDDO=3.3V, 2.5V or 1.8V
VCC
RU2
SPARE
(U1-26)
R5
50
Set Logic
Input to '1'
(U1-42)
C6
0.1u
Set Logic
Input to '0'
RS 43
VDDO
(U1-38)(U1-1)
C8
0.1u
(U1-34)
C3
0.1u
R3
50
Ro+Rs=50 Ohm
C2
0.1u
U1
ICS87016
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
36
35
34
33
32
31
30
29
28
27
26
25
48
47
46
45
44
43
42
41
40
39
38
37
VDD
CLK0
DIV_SELA
DIV_SELB
DIV_SELC
DIV_SELD
CLK_ENA
CLK_ENB
CLK_ENC
CLK_END
nMR/OE
GND
QD3
VDDOD
QD2
GND
QD1
VDDOD
QD0
GND
QC3
VDDOC
QC2
GND
GND
QB0
VDDOB
QB1
GND
QB2
VDDOB
QB3
GND
QC0
VDDOC
QC1
VDD
CLK1
nCLK1
CLK_SEL
GND
QA0
VDDOA
QA1
GND
QA2
VDDOA
QA3
(U1-14)
Zo = 50RD2
1K
VDDO
Zo = 50
Zo = 50
VDD=3.3V
(U1-18) (U1-30)
To Logic
Input
pins
LVMCOS driver through series termination. The 87016 outputs
are LVCMOS drivers. Series termination is shown in this sche-
matic. Additional LVCMOS termination approaches are shown
in the LVCMOS Termination Application Note.

87016AYLF

Mfr. #:
Manufacturer:
IDT
Description:
Clock Generators & Support Products 16 LVCMOS OUT BUFFER/DIVIDER
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
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