2 X 2 PROTECTION CROSSPOINT SWITCH DESCRIPTION FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ SuperLite™ SY55854U Guaranteed fMAX >2.5GHz over temperature 2.3V to 5.7V power supply Non-blocking “switch architecture” Guaranteed <15ps channel-to-channel skew Guaranteed <480ps propagation delay over temperature Configurable as 2:1 mux, 1:2 fan-out buffer, dual buffer, or 2 x 2 switch Accepts CML, PECL, LVPECL inputs Fully differential inputs/outputs Source terminated CML outputs for fast edge rates Wide operating temperature range: –40°C to +85°C Available in a tiny 16-pin EPAD-QSOP package The SY55854U is a fully differential, CML, 2 x 2crosspoint switch. The non-blocking design allows any input to be connected to any output. Varying the state of the select inputs allows SY55854U to be used in backup, fault tolerant, protection, and backplane distribution applications. SY55854U inputs can be terminated with a single resistor between the true and the complement pins of a given input. The SY55854U is a member of Micrel’s new SuperLite™ family of high-speed logic devices. This family features very small packaging, high signal integrity, and flexible supply voltage operation. PIN CONFIGURATION GND 1 APPLICATIONS D0 2 15 Q0 /D0 3 14 /Q0 S0 4 ■ ■ ■ ■ ■ 16 VCC QSOP 13 S1 /S0 5 12 /S1 /D1 6 11 /Q1 D1 7 10 Q1 GND 8 9 High-speed logic Data communications systems Wireless communications systems Telecom systems Backplane redundancy VCC 16-Pin QSOP PIN NAMES FUNCTIONAL BLOCK DIAGRAM S0 Pin S1 D0 0S Q0 D1 1 0S Q1 Function D0, /D0 CML/PECL/LVPECL Input Data D1, /D1 CML/PECL/LVPECL Input Data Q0, /Q0 CML Output Data Q1, /Q1 CML Output Data S0, /S0 CML/PECL/LVPECL Select Input S1, /S1 CML/PECL/LVPECL Select Input GND Ground VCC VCC 1 SuperLite is a trademark of Micrel, Inc. Rev.: A 1 Amendment: /0 Issue Date: June 2001 SuperLite™ SY55854U Micrel PIN DESCRIPTIONS Q1, /Q1 – CML Output (Differential) This is the other output from the crosspoint. Input S1 selects either the D0 or D1 input to be switched to this output. D0, /D0 – CML/PECL/LVPECL Input (Differential) This is one of the data inputs to the crosspoint. It will be switched either to the Q0 output, the Q1 output, both outputs, or neither output, depending on the state of the S0 and S1 inputs. S0, /S0 – CML/PECL/LVPECL Input (Differential) This selects input chooses which data input switches to the Q0 output. S0 logic low selects the D0 input, while S0 logic high selects the B input. D1, /D1 – CML/PECL/LVPECL Input (Differential) This is the other data input to the crosspoint. It will be switched either to the Q0 output, the Q1 output, both outputs, or neither output, depending on the state of the S0 and S1 inputs. S1, /S1 – CML/PECL/LVPECL Input (Differential) This select input chooses which data input switches to the Q1 output. S1 logic low selects the D0 input, while S1 logic high selects the D1 input. Q0, /Q0 – CML Output (Differential) This is one output from the crosspoint. Input S0 selects either the D0 or the D1 input to be switched to this output. FUNCTIONAL DESCRIPTION Establishing Static Logic Inputs The true pin of an input pair is internally biased to ground through a 75kΩ resistor. The complement pin of an input pair is internally biased halfway between VCC and ground by a voltage divider consisting of two 75kΩ resistors. In this way, unconnected inputs appear as logic zeros. To keep an VCC X NC /X input at static logic zero at VCC > 3.0V, leave both inputs unconnected. For VCC ≤ 3.0V, connect the complement input to VCC and leave the true input unconnected. To make an input static logic one, connect the true input to VCC, leave the complement input unconnected. These are the only two safe ways to cause inputs to be at a static value. In particular, no input pin should be directly connected to ground. All NC (no connect) pins should be unconnected. NC X NC /X VCC > 3.0V Figure 1. Hard Wiring a Logic “1” (1) NOTE: 1. X is either D0, D1, S0, or S1 input. /X is either /D0, /D1, /S0, or /S1 input. NC X VCC /X VCC ≤ 3.0V Figure 2. Hard Wiring a Logic “0” (1) Usage SY55854U is very versatile. Tying its select inputs in various ways varies its functionality. For example, tying the select inputs together turns SY55854U into a redundant distributor. Either input will be switched to both outputs simultaneously. This is very useful in redundant backplane applications. By cross-tying the select inputs, SY55854U becomes a true crosspoint, selecting between “straight through” and “cross connected” operation. Also, using the select inputs independently, SY55854U functions as two multiplexers. Setting the select inputs to static values turns SY55854U into a dual buffer, or a fan-out buffer. To make larger crosspoints, cascade SY55854U devices, either in a tree or in a Banyan structure, as appropriate for your application. 2 SuperLite™ SY55854U Micrel TRUTH TABLE S0 S1 Q0 Q1 Function 0 0 D0 D0 Fan-Out Buffer 0 1 D0 D1 Dual Buffer 1 0 D1 D0 Dual Buffer 1 1 D1 D1 Fan-Out Buffer CTL CTL Same Same Redundant Distribution CTL /CTL Opposite Opposite Crosspoint CML TERMINATION All inputs accept the output from any other member of this family. All outputs are source terminated 100Ω CML differential drivers as shown in Figures 3 and 4. SY55854U expects the inputs to be terminated, and that good high vcc 100Ω speed design practices be adhered to. SY55854U inputs are designed to accept a termination resistor between the true and complement inputs of a differential pair. 0402 form factor chip resistors will fit with some trace fanout. vcc vcc 100Ω 100Ω 100Ω 50Ω 100Ω 100Ω 100Ω 50Ω 100Ω 100Ω 50Ω 50Ω 50Ω 8mA 8mA SY55854U SY55854U Figure 3a. Differentially Terminated (50Ω Load CML Output) Figure 3b. Individually Terminated (50Ω Load CML Output) VCC 100Ω 100Ω 100Ω 200Ω 100Ω 8mA SY55854U Figure 4. 100Ω Load CML Output 3 50Ω SuperLite™ SY55854U Micrel ABSOLUTE MAXIMUM RATINGS(1) Symbol Rating Value Unit –0.5 to +6.0 V –0.5 to VCC +0.5 V VCC Power Supply Voltage VI Input Voltage VO CML Output Voltage VCC –1.0 to VCC +0.5 V TA Operating Temperature Range –40 to +85 °C Tstore Storage Temperature Range –65 to +150 °C 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 VCC = 2.3V to 5.7V; GND = 0V TA = –40°C Symbol Parameter TA = 0°C TA = +25°C TA = +85°C Min. Max. Min. Max. Min. Max. Min. Max. Unit VCC Power Supply Voltage 2.3 5.7 2.3 5.7 2.3 5.7 2.3 5.7 V ICC Power Supply Current — 60 — 60 — 60 — 60 mA CML DC ELECTRICAL CHARACTERISTICS VCC = 2.3V to 5.7V; GND = 0V; TA = –40°C to +85°C(1) Symbol Parameter Min. Typ. Max. Unit VID Differential Input Voltage 100 — — mV VIH Input HIGH Voltage 1.6 — VCC V VIL Input LOW Voltage 1.5 — VCC – 0.1 V VOH Output HIGH Voltage VCC – 0.020 VCC – 0.010 VCC V No Load VOL Output LOW Voltage VCC – 0.97 VCC – 0.825 VCC – 0.660 V No Load 0.700 0.800 0.400 0.200 0.950 V No Load 100Ω Environment(4) 50Ω Environment(3) 80 100 120 Ω Swing(2) VOS Output Voltage RDRIVE Output Source Impedance Condition NOTES: 1. Equilibrium temperature. 2. Actual voltage levels and differential swing will depend on customer termination scheme. Typically, a 400mV swing is available in the 100Ω environment and a 200mV swing in the 50Ω environment. Refer to the “CML Termination” diagram for more details. 3. See Figure 3a and 3b. 4. See Figure 4. 4 SuperLite™ SY55854U Micrel AC ELECTRICAL CHARACTERISTICS(1) VCC = 2.3V to 5.7V; GND = 0V; TA = –40°C to +85°C Symbol Min. Typ. Max. Unit fMAX Max. Operating Frequency Parameter 2.5 — — GHz tPLH tPHL Propagation Delay, S0, S1, D0, D1 to Q0, Q1 — — 400 ps tSKEW Within-Device Skew(2) Part-to-Part Skew (Diff.) — — — — 15 100 ps tr tf CML Output Rise/Fall Times (20% to 80%) — — 150 ps NOTES: 1. Tested using environment of Figure 3b, 50Ω load CML output. 2. Worst case difference between Q0 and Q1 from either A or B, when both outputs come from the same input PRODUCT ORDERING CODE Ordering Code Package Type Operating Range Package Marking SY55854UYI Y16-1 Industrial 854U SY55854UYITR Y16-1 Industrial 854U 5 Condition SuperLite™ SY55854U Micrel 16 LEAD EPAD-QSOP (Y16-1) PIN 1 DIMENSIONS: INCHES (MM) 0.157 (3.99) 0.150 (3.81) 0.009 (0.2286) REF 0.025 (0.635) BSC 0.0098 (0.249) 0.0040 (0.102) 0.012 (0.30) 0.008 (0.20) 0.196 (4.98) 0.189 (4.80) SEATING 0.0688 (1.748) PLANE 0.0532 (1.351) MICREL-SYNERGY TEL + 1 (408) 980-9191 FAX 0.0098 (0.249) 0.0075 (0.190) 45° 8° 0° 0.050 (1.27) 0.016 (0.40) 0.2284 (5.801) 0.2240 (5.690) 3250 SCOTT BOULEVARD SANTA CLARA CA 95054 + 1 (408) 914-7878 WEB USA http://www.synergysemi.com http://www.micrel.com This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc. © 2001 Micrel Incorporated 6