■ Configurable as dual 2:1 mux, dual 1:2 fanout buffer,
1:4 fanout buffer, quad buffer, or dual 2 x 2 switch
■ 50Ω compatible outputs
■ Unique input termination and VT pin for DC-coupled
and AC-coupled input signals–CML or PECL
■ Fully differential inputs/outputs
■ TTL/CMOS compatible control logic
■ Wide supply voltage range: 2.3V to 3.6V
■ Wide operating temperature range: –40°C to +85°C
■ Available in 32-pin EPAD-TQFP package
> 3.0GHz (3Gbps)
MAX
SuperLite™
SuperLite™
SY55858U
SY55858U
SuperLite™
DESCRIPTION
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 50Ω compatible differential CML (currentmode 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
internal termination design that allows access to the
termination network through VT 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.
and DB
0–1
) have a unique
0–1
APPLICATIONS
■ SONET/SDH optical transport
■ Backplane redundancy
■ Add-drop Multiplexers
SuperLite is a trademark of Micrel, Inc.
M9999-110705
1. Contact factory for die availability. Dice are guaranteed at TA = 25°C, DC Electricals only.
2. Tape and Reel.
(2)
(3)
(2, 3)
3. Pb-Free package recommended for new designs.
TRUTH TABLES
SELA0SELA1QA0QA1Function
00DA0DA0Fanout Buffer or Redundant Distribution
01DA0DA1Dual Buffer or Crosspoint
10DA1DA0Dual Buffer or Crosspoint
11DA1DA1Fanout Buffer or Redundant Distribution
Table 1. Input to Output Connectivity Crosspoint A
SELB0SELB1QB0QB1Function
00DB0DB0Fanout Buffer or Redundant Distribution
01DB0DB1Dual Buffer or Crosspoint
10DB1DB0Dual Buffer or Crosspoint
11DB1DB1Fanout Buffer or Redundant Distribution
Table 2. Input to Output Connectivity Crosspoint B
M9999-110705
hbwhelp@micrel.com or (408) 955-1690
2
SuperLite™
Micrel, Inc.
PIN DESCRIPTION
Pin NumberPin NamePin Function
1DB1Channel B1 posititve signal input.
2VTB1Channel B1 termination center-tap. For CML inputs, leave this pin floating.
Otherwise, see Figures 5a–5d in “Input Interface Application” section.
3/DB1Channel B1 negative signal input.
4SELB0Channel B0 output select. TTL/CMOS input.
5DB0Channel B0 positive signal input.
6VTB0Channel B0 termination center-tap. For CML inputs, leave this pin floating.
Otherwise, see Figures 5a–5d in “Input Interface Application” section.
7/DB0Channel B0 negative signal input.
8SELB1Channel B1 output select. TTL/CMOS input.
9, 24GNDSupply Ground.
10, 13, 16, 17, 20, 23VCCPositive supply normally connect to 2.5V, 3.3V, or 5V nominal supply, and
bypass each pin with 0.1µF//0.01µF low ESR capacitors.
11/QB0Channel B0 negative signal output. 50Ω CML.
12QB0Channel B0 positive signal output. 50Ω CML.
14/QB1Channel B1 negative signal output. 50Ω CML.
15QB1Channel B1 positive signal output. 50Ω CML.
18/QA1Channel A1 negative signal output. 50Ω CML.
19QA1Channel A1 positive signal output. 50Ω CML.
21/QA0Channel A0 negative signal output. 50Ω CML.
22QA0Channel A0 positive signal output. 50Ω CML.
25DA0Channel A0 positive signal input.
26VTA0Channel A0 termination center-tap. For CML inputs, leave this pin floating.
Otherwise, see Figures 5a–5d in “Input Interface Application” section.
27/DA0Channel A0 negative signal input.
28SELA1Channel A1 output select. TTL/CMOS input.
29DA1Channel A1 positive signal input.
30VTA1Channel A1 termination center-tap. For CML inputs, leave this pin floating.
Otherwise, see Figures 5a–5d in “Input Interface Application” section.
Note 1. See “Input Interface Applications” section for proper input
M9999-110705
hbwhelp@micrel.com or (408) 955-1690
connection.
1.2mA
50Ω
1.2mA
SY55858U
v
cc
50Ω50Ω
16mA
SY55858U
Q
/Q
Figure 2. Output Stage
4
Micrel
SuperLite™
SY55858U
ABSOLUTE MAXIMUM RATINGS
(1)
SymbolRatingValueUnit
V
V
V
T
T
T
θ
CC
IN
OUT
A
LEAD
store
JA
Power Supply Voltage–0.5 to +6.0V
Input Voltage–0.5 to V
+0.5V
CC
CML Output VoltageVCC –1.0 to VCC +0.5V
Operating Temperature Range–40 to +85°C
Lead Temperature (soldering, 20sec.)260°C
Storage Temperature Range–65 to +150°C
Package Thermal Resistance–Still-Air (multi-layer PCB)28°C/W
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.
DC ELECTRICAL CHARACTERISTICS
SymbolParameterMin.Typ.Max.UnitCondition
V
CC
I
CC
Power Supply Voltage2.3—3.6V
Power Supply Current—150190mANo load, over temp.
TTL CONTROL ELECTRICAL CHARACTERISTICS
VCC = 2.3V to 3.6V; GND = 0V; TA = –40°C to +85°C
SymbolParameterMin.Typ.Max.UnitCondition
V
IH
V
IL
I
IH
I
IL
Note 2. Specifications are guaranteed after thermal equilibrium has been establised.
Input HIGH Voltage2.0——V
Input LOW Voltage——0.8V
Input HIGH Current——+20µAVIN = 2.7V, VCC = Max.
——+100µAVIN = VCC, VCC = Max.
Input LOW Current–300——µAVIN = 0.5V, VCC = Max.
(2)
5
SuperLite™
Micrel, Inc.
SY55858U
CML DC ELECTRICAL CHARACTERISTICS
VCC = 2.3V to 3.6V; GND = 0V; TA = –40°C to +85°C
SymbolParameterMin.Typ.Max.UnitCondition
V
ID
R
IN
V
IH
V
IL
V
OH
V
OL
V
OUT(SWING)
R
OUT
Note 3. Device is guaranteed to meet the DC specifications, shown in the table above, after thermal equilibrium has been established. The device is
D-to-/D90100110Ω
Input HIGH Voltage1.6—V
Input LOW Voltage1.5—VCC – 0.1V
Output HIGH VoltageVCC – 0.040VCC – 0.010V
Output LOW VoltageVCC – 1.00VCC – 0.800VCC – 0.650VNo Load
Output Voltage Swing
(4)
0.6500.8001.00VNo Load
Output Source Impedance405060Ω
tested in a socket such that traverse airflow ≥500lfpm is maintained.
OUT(SWING)
purposes is 2 ×V
swing is available in the 50Ω environment. Refer to the “CML Output Termination Application” section, Figures 3 and 4, for more details.
is defined as the swing on one output of a differential pair, that is |VOH – VOL| on one pin. The swing for common mode immunity
OUT(SWING)
. Actual voltage levels and differential swing will depend on customer termination scheme. Typically, a 400mV
(3)
CC
CC
V
VNo Load
—0.400—50Ω Environment
AC ELECTRICAL CHARACTERISTICS
VCC = 2.3V to 3.6V; GND = 0V; TA = –40°C to +85°C
SymbolParameterMin.Typ.Max.UnitCondition
f
MAX
t
PLH
t
PHL
t
SWITCH
t
SKEW
R
J
D
J
tr, t
f
Note 5. Tested using environment of Figure 3, 50Ω equivalent load. AC parameters are guaranteed by design and characterization.
Note 6. f
Note 7. Input TTL/CMOS edge rate of <1.5ns.
Note 8. Worst-case difference between QA0 and QA1 from either DA0 or DA1 (or between QB0 and QB1 from either DB0 or DB1 respectively), when
Note 9. Worst-case difference between QA and QB outputs, when DA or DB inputs are shorted.
Maximum Frequency
NRZ Data Rate3.0——Gbps
Clock Frequency
(6)
3.0——GHz
Differential Propagation Delay220350450ps
D-to-Q
(8)
(9)
(7)
—0.501.0ns
—1225ps
—2550ps
Select-to-Valid Output
Within-Device Skew
Within-Device Skew
Part-to-Part Skew (Diff.)—100—
Random Jitter—25ps
Deterministic Jitter—520ps
CML Output Rise/Fall Times—80120ps
(20% to 80%)
clock is defined as the maximum toggle rate the device can operate while still achieving a 250mV minimum CML output swing, 50Ω
MAX
equivalent load.
both outputs come from the same input.
(5)
RMS
PP
M9999-110705
hbwhelp@micrel.com or (408) 955-1690
6
Micrel, Inc.
T
CML OUTPUT TERMINATION APPLICATION
SuperLite™
SY55858U
All CML inputs accept a CML output from any other
member of this family. All CML outputs are source terminated
v
cc
50Ω50Ω
16mA
SY55858U
50Ω
100Ω
50Ω
Figure 3. 50Ω Output Termination
INPUT INTERFACE APPLICATIONS
50Ω differential drivers as shown in Figure 3.
+
Q
OUT
400mV
(Single-Ended)
/Q
OUT
Q
OUT
800mV
(Q
OUT — /QOU
Differential
/Q
OUT
Figure 4. Output Levels
V
CC
CML
V
D
/D
VTNC
CC
SY55858
Figure 5a. CML-to-CML
(DC-Coupled) Input Interface
V
CC
PECL
VCC – 2.0V
V
D
/D
SY55858
VT
CC
V
CC
CML
VCC – 1.3V
V
D
/D
SY55858
VT
CC
Figure 5b. CML-to-CML
(AC-Coupled) Input Interface
V
CC
PECL
220Ω220Ω
VCC – 1.3V
V
D
/D
SY55858
VT
CC
Figure 5c. PECL-to-CML
(DC-Coupled) Input Interface
M9999-110705
hbwhelp@micrel.com or (408) 955-1690
Figure 5d. PECL-to-CML
(AC-Coupled) Input Interface
7
Micrel, Inc.
32 -PIN EPAD-TQFP (DIE UP) (H32-1)
SuperLite™
SY55858U
Rev. 01
MICREL, INC. 2180 FORTUNE DRIVESAN JOSE, CA 95131USA
The information furnished by Micrel in this datasheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use.
Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can
reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into
the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser’s
use or sale of Micrel Products for use in life support appliances, devices or systems is at Purchaser’s own risk and Purchaser agrees to fully indemnify
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Micrel for any damages resulting from such use or sale.