1
SuperLiteTM
SY55858U
Micrel
DESCRIPTION
s
Guaranteed AC parameters over temperature:
f
MAX
> 3.0GHz (3Gbps)
t
r
/ t
f
< 120ps
Within-device skew < 25ps
s
Non-blocking "switch architecture"
s
Configurable as dual 2:1 mux, dual 1:2 fanout buffer,
1:4 fanout buffer, quad buffer, or dual 2 x 2 switch
s
50
compatible outputs
s
Unique input termination and V
T
pin for DC-coupled
and AC-coupled input signalsCML or PECL
s
Fully differential inputs/outputs
s
TTL/CMOS compatible control logic
s
Wide supply voltage range: 2.3V to 3.6V
s
Wide operating temperature range: 40
C to +85
C
s
Available in 32-pin EPAD-TQFP package
The SY55858U is a low-voltage, high-speed dual 2 x 2
crosspoint switch with a flexible input that accepts CML
or PECL, and a 50
compatible differential CML (current-
mode logic) output. The non-blocking design allows any
input to connect to any output. Varying the state of the
select inputs allows SY55858U to be used in backup,
fault tolerant, protection and backplane distribution
applications.
The signal inputs (DA
01
and DB
01
) have a unique
internal termination design that allows access to the
termination network through V
T
pins. This feature allows
the device to easily interface to other logic standards
such as AC-coupled or DC-coupled PECL/LVPECL
signals. For applications that require a single-channel
2 x 2 crosspoint, consider the SY55854.
FEATURES
2.5V/3.3V 3.0GH
Z
DUAL 2 x 2 CML
CROSSPOINT SWITCH
W
/INTERNAL TERMINATION
SuperLiteTM
SY55858U
APPLICATIONS
s
SONET/SDH optical transport
s
Backplane redundancy
s
Add-drop Multiplexers
Rev.: C
Amendment: /1
Issue Date:
September 2003
SuperLite is a trademark of Micrel, Inc.
32 31 30 29 28 27 26 25
9
10 11 12 13 14 15 16
1
2
3
4
5
6
7
8
24
23
22
21
20
19
18
17
DB1
VTB1
/DB1
SELB0
DB0
VTB0
/DB0
SELB1
GND
VCC
QA0
/QA0
VCC
QA1
/QA1
VCC
SELA0
/DA1
VT
A1
DA1
SELA1
/DA0
VT
A0
DA0
GND
VCC
/
QB0
QB0
VCC
/
QB1
QB1
VCC
Top View
EPAD-TQFP
H32-1
PIN CONFIGURATION
SuperLiteTM
2
SuperLiteTM
SY55858U
Micrel
FUNCTIONAL BLOCK DIAGRAM
A0
0
1
0
1
A1
DA0
/DA0
V
TA0
50
50
DA1
/DA1
V
TA1
50
50
CML
CML
SELA0
SELA1
QA0
/QA0
QA1
/QA1
B0
0
1
0
1
B1
DB0
/DB0
V
TB0
50
50
DB1
/DB1
V
TB1
50
50
CML
CML
SELB0
SELB1
QB0
/QB0
QB1
/QB1
INPUT AND OUTPUT STAGE
50
SY55858U
V
CC
1.2mA
50
D0
V
T
*
/D0
1.2mA
Figure 1. Input Stage
50
50
SY55858U
v
cc
Q
16mA
/Q
Figure 2. Output Stage
Note 1.
See "Input Interface Applications" section for proper input
connection.
3
SuperLiteTM
SY55858U
Micrel
PIN DESCRIPTION
Pin Number
Pin Name
Pin Function
1
DB1
Channel B1 posititve signal input.
2
VTB1
Channel B1 termination center-tap. For CML inputs, leave this pin floating.
Otherwise, see Figures 5a5d in "Input Interface Application" section.
3
/DB1
Channel B1 negative signal input.
4
SELB0
Channel B0 output select. TTL/CMOS input.
5
DB0
Channel B0 positive signal input.
6
VTB0
Channel B0 termination center-tap. For CML inputs, leave this pin floating.
Otherwise, see Figures 5a5d in "Input Interface Application" section.
7
/DB0
Channel B0 negative signal input.
8
SELB1
Channel B1 output select. TTL/CMOS input.
9, 24
GND
Supply Ground.
10, 13, 16, 17, 20, 23
VCC
Positive supply normally connect to 2.5V, 3.3V, or 5V nominal supply, and
bypass each pin with 0.1
F//0.01
F low ESR capacitors.
11
/QB0
Channel B0 negative signal output. 50
CML.
12
QB0
Channel B0 positive signal output. 50
CML.
14
/QB1
Channel B1 negative signal output. 50
CML.
15
QB1
Channel B1 positive signal output. 50
CML.
18
/QA1
Channel A1 negative signal output. 50
CML.
19
QA1
Channel A1 positive signal output. 50
CML.
21
/QA0
Channel A0 negative signal output. 50
CML.
22
QA0
Channel A0 positive signal output. 50
CML.
25
DA0
Channel A0 positive signal input.
26
VTA0
Channel A0 termination center-tap. For CML inputs, leave this pin floating.
Otherwise, see Figures 5a5d in "Input Interface Application" section.
27
/DA0
Channel A0 negative signal input.
28
SELA1
Channel A1 output select. TTL/CMOS input.
29
DA1
Channel A1 positive signal input.
30
VTA1
Channel A1 termination center-tap. For CML inputs, leave this pin floating.
Otherwise, see Figures 5a5d in "Input Interface Application" section.
31
/DA1
Channel A1 negative signal input.
32
SELA0
Channel A1 output select. TTL/CMOS input.
4
SuperLiteTM
SY55858U
Micrel
SELA0
SELA1
QA0
QA1
Function
0
0
DA0
DA0
Fanout Buffer or Redundant Distribution
0
1
DA0
DA1
Dual Buffer or Crosspoint
1
0
DA1
DA0
Dual Buffer or Crosspoint
1
1
DA1
DA1
Fanout Buffer or Redundant Distribution
TRUTH TABLES
Table 1. Input to Output Connectivity Crosspoint A
SELB0
SELB1
QB0
QB1
Function
0
0
DB0
DB0
Fanout Buffer or Redundant Distribution
0
1
DB0
DB1
Dual Buffer or Crosspoint
1
0
DB1
DB0
Dual Buffer or Crosspoint
1
1
DB1
DB1
Fanout Buffer or Redundant Distribution
Table 2. Input to Output Connectivity Crosspoint B
Symbol
Rating
Value
Unit
V
CC
Power Supply Voltage
0.5 to +6.0
V
V
IN
Input Voltage
0.5 to V
CC
+0.5
V
V
OUT
CML Output Voltage
V
CC
1.0 to V
CC
+0.5
V
T
A
Operating Temperature Range
40 to +85
C
T
store
Storage Temperature Range
65 to +150
C
JA
Package Thermal Resistance
Still-Air (multi-layer PCB)
28
C/W
(Junction-to-Ambient)
500lfpm (multi-layer PCB)
20
C/W
JC
Package Thermal Resistance
4
C/W
(Junction-to-Case)
Note 1.
Permanent device damage may occur if ABSOLUTE MAXIMUM RATINGS are exceeded. This is a stress rating only and functional operation
is not implied at conditions other than those detailed in the operational sections of this data sheet. Exposure to ABSOLUTE MAXIMUM
RATlNG conditions for extended periods may affect device reliability.
ABSOLUTE MAXIMUM RATINGS
(1)
5
SuperLiteTM
SY55858U
Micrel
Symbol
Parameter
Min.
Typ.
Max.
Unit
Condition
V
ID
Differential Input Voltage
100
--
--
mV
R
IN
Differential Input Resistance
D-to-/D
80
100
120
V
IH
Input HIGH Voltage
1.6
--
V
CC
V
V
IL
Input LOW Voltage
1.5
--
V
CC
0.1
V
V
OH
Output HIGH Voltage
V
CC
0.040
V
CC
0.010
V
CC
V
No Load
V
OL
Output LOW Voltage
V
CC
1.00
V
CC
0.800
V
CC
0.650
V
No Load
V
OUT(SWING)
Output Voltage Swing
(3)
0.650
0.800
1.00
V
No Load
--
0.400
--
50
Environment
R
OUT
Output Source Impedance
40
50
60
Note 1.
Specification for packaged product only.
Note 2.
Device is guaranteed to meet the DC specifications, shown in the table above, after thermal equilibrium has been established. The device is
tested in a socket such that traverse airflow
500lfpm is maintained.
Note 3.
V
OUT(SWING)
is defined as the swing on one output of a differential pair, that is |V
OH
V
OL
| on one pin. The swing for common mode immunity
purposes is 2
V
OUT(SWING)
. Actual voltage levels and differential swing will depend on customer termination scheme. Typically, a 400mV
swing is available in the 50
environment. Refer to the "CML Output Termination Application" section, Figures 3 and 4, for more details.
CML DC ELECTRICAL CHARACTERISTICS
(1)
V
CC
= 2.3V to 3.6V; GND = 0V; T
A
= 40
C to +85
C
(2)
Symbol
Parameter
Min.
Typ.
Max.
Unit
Condition
V
CC
Power Supply Voltage
2.3
--
3.6
V
I
CC
Power Supply Current
--
150
190
mA
No load, over temp.
Note 1.
Specification for packaged product only.
DC ELECTRICAL CHARACTERISTICS
(1)
Symbol
Parameter
Min.
Typ.
Max.
Unit
Condition
V
IH
Input HIGH Voltage
2.0
--
--
V
V
IL
Input LOW Voltage
--
--
0.8
V
I
IH
Input HIGH Current
--
--
+20
A
V
IN
= 2.7V, V
CC
= Max.
--
--
+100
A
V
IN
= V
CC
, V
CC
= Max.
I
IL
Input LOW Current
300
--
--
A
V
IN
= 0.5V, V
CC
= Max.
Note 1.
Specification for packaged product only.
Note 2.
Specifications are guaranteed after thermal equilibrium has been establised.
TTL CONTROL ELECTRICAL CHARACTERISTICS
(1)
V
CC
= 2.3V to 3.6V; GND = 0V; T
A
= 40
C to +85
C
(2)
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