SY56028XR_1009 Datasheet, PDF (3/11 Pages) Micrel Semiconductor – Low Voltage 1.2V/1.8V/2.5V CML 4:1 MUX with 1:2 FANOUT 6.4Gbps with EQUALIZATION

Micrel, Inc.
SY56028XR
Pin Description
Pin Number
1,3
5,7
25,27
29,31
Pin Name
IN0, /IN0
IN1, /IN1
IN2, /IN2
IN3, /IN3
Pin Function
Differential Inputs: Accepts differential signals as small as 200mV (400mVPP)
applied to the input of a 9, 18 or 27 inch 6mil FR4 stripline transmission line. See
“Input and Output Stage” section for details of this input.
2
6
26
30
19
15
18
16,17
10,13,20,23
4,8,9,24,28,32
12,11
22,21
VT0
VT1
VT2
VT3
EQ
SEL0
SEL1
VCC
VCCO
GND,
Exposed pad
Q0, /Q0
Q1, /Q1
Input Termination Center-Tap: Each side of the differential input pair terminates to
the VT pin. This pin provides a center-tap to a termination network for maximum
interface flexibility. An internal high impedance resistor divider biases VT to allow
input AC coupling. For AC coupling, bypass VT with 0.1µF low ESR capacitor to
VCC. See “Input Interface Applications” subsection and Figure 2a.
Three level input for equalization control.
Single-ended TTL/CMOS compatible input selects the inputs to the multiplexer. This
input is internally connected to a 25kΩ pull-up resistor and will default to a logic
HIGH state if left open. Input logic threshold is VCC/2. See “Truth Table” for select
control.
Positive Power Supply: Bypass with 0.1uF//0.01uF low ESR capacitors as close to
the VCC pin as possible. Supplies the input and core circuitry.
Output Supply: Bypass with 0.1uF//0.01uF low ESR capacitors as close to the VCCO
pin as possible. Supplies the output buffers.
Ground: Exposed pad must be connected to a ground plane that is the same
potential as the ground pins.
CML Differential Output Pair: Differential buffered copy of the input signal. The
output swing is typically 390mV. See “Functional Description” subsection for
termination information.
Truth Table
EQ Input
LOW
FLOAT
HIGH
Equalization FR4 6mil
Stripline
9“
18”
27”
SEL1
0
0
1
1
SEL0
0
1
0
1
IN0 Input Selected
IN1 Input Selected
IN2 Input Selected
IN3 Input Selected
April 2010
3
M9999-040810-A
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