ICS85214

LOW SKEW, 1-TO-5, DIFFERENTIAL-TO-HSTL FANOUT BUFFER

IDT™ / ICS™ HSTL FANOUT BUFFER

9

ICS85214AG

REV. B

JUNE 3, 2016

Recommendations for Unused Input and Output Pins

Inputs:

LVCMOS Control Pins

All control pins have internal pull-ups or pull-downs; additional

resistance is not required but can be added for additional

protection. A 1k

 resistor can be used.

CLK/CLK INPUTS

For applications not requiring the use of the differential input, both

CLK and CLK can be left floating. Though not required, but for

additional protection, a 1k

 resistor can be tied from CLK0 to

ground.

CLK INPUT

For applications not requiring the use of a clock input, it can be left

floating. Though not required, but for additional protection, a 1k



resistor can be tied from the CLK input to ground.

Outputs:

HSTL Outputs

All unused HSTL outputs can be left floating. We recommend that

there is no trace attached. Both sides of the differential output pair

should either be left floating or terminated.

Schematic Example

Figure 4 shows a schematic example of the ICS85214. In this

example, the input is driven by an IDT HiPerClockS HSTL driver.

The decoupling capacitors should be physically located near the

power pin. For ICS85214, the unused clock outputs can be left

floating.

Figure 4. ICS85214 HSTL Buffer Schematic Example

Zo = 50 Ohm

R9

50

R11

1K

U1

ICS85214

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

20

19

18

17

Q0

nQ0

Q1

nQ1

Q2

nQ2

Q3

nQ3

Q4

nQ4

GND

CLK_SEL

nc

nCLK

CLK

SCLK

VDDO

nCLK_EN

VDD

nc

3.3V

Zo = 50 Ohm

R1

50

C2

0.1u

Zo = 50

R4

50

R7

50

LVHSTL Driver

R12

1K

R10

50

R3

50

Zo = 50

C1

0.1u

1.8V

Zo = 50

+

-

+

-

Zo = 50

Zo = 50

+

-

R8

50

Zo = 50

1.8V

R2

50