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19-1854; Rev 1; 11/01 +3.3V, 2.7Gbps Dual 2 General Description The MAX3840 is a dual 2 2 asynchronous crosspoint switch for SDH/SONET DWDM and other high-speed data switching applications where serial data stream loop-through and protection channel switching are required. It is ideal for OC-48 systems with forward error correction. A high-bandwidth, fully differential signal path minimizes jitter accumulation, crosstalk, and signal skew. Each 2 2 crosspoint switch can fan out and/or multiplex up to 2.7Gbps data and 2.7GHz clock signals. All inputs and outputs are current mode logic (CML) compatible and easily adaptable to interface with an AC-coupled LVPECL signal. When not used, each CML output stage can be powered down with an enable control to conserve power. The typical power consumption is 460mW with all outputs enabled. The MAX3840 is compatible with the MAX3876 2.5Gbps clock and data recovery (CDR) circuit. The MAX3840 is available in a 32-pin exposed-pad QFN package (5mm 5mm footprint) and operates from a +3.3V supply over a temperature range of -40C to +85C. 2 Crosspoint Switch Features MAX3840 o Single +3.3V Supply o 460mW Power Consumption o 2psRMS Random Jitter o 7psP-P Deterministic Jitter o Power-Down Feature for Deselected Outputs o CML Inputs/Outputs o 6ps Channel-to-Channel Skew o 100ps Output Edge Speed o 5mm 5mm 32 QFN Package ________________________Applications SDH/SONET and DWDM Transport Systems Add-Drop Multiplexers ATM Switch Cores WDM Cross-Connects High-Speed Backplanes PART MAX3840EGJ Ordering Information TEMP RANGE -40C TO +85C PIN-PACKAGE 32 QFN Pin Configuration appears at end of data sheet. Typical Application Circuit VCC = +3.3V MAX3866 TIA AND LA MAX3876 CDR DATA MAX3869 LASER DRIVER CLOCK MAX3866 TIA AND LA MAX3876 CDR DATA MAX3840 CROSSPOINT SWITCH MAX3869 LASER DRIVER CLOCK ZO = 50 TRANSMISSION LINE ________________________________________________________________ Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com. +3.3V, 2.7Gbps Dual 2 MAX3840 ABSOLUTE MAXIMUM RATINGS 2 Crosspoint Switch Supply Voltage, VCC .............................................-0.5V to +5.0V Input Voltage (CML) .........................(VCC - 1.0) to (VCC + 0.5V) TTL Control Input Voltage...........................-0.5V to (VCC + 0.5V) Output Currents (CML) .......................................................22mA Continuous Power Dissipation at TA = +85C 32-Pin QFN (derate 29.4mW/C)...................................1.9W Operating Temperature Range ...........................-40C to +85C Operating Junction Temperature Range ...........-55C to +150C Storage Temperature Range .............................-65C to +160C Lead Temperature (soldering, 10s) .................................+300C Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. DC ELECTRICAL CHARACTERISTICS (VCC = +3.0V to +3.6V, TA = -40C to +85C. Typical values are at VCC = +3.3V, TA = +25C, unless otherwise noted.) PARAMETER Supply Current CML Differential Output Swing Differential Output Impedance CML Output Common-Mode Voltage CML Single-Ended Input Voltage Range CML Differential Input Voltage Swing CML Single-Ended Input Impedance TTL SPECIFICATIONS TTL Input High Voltage TTL Input Low Voltage TTL Input High Current TTL Input Low Current VIH VIL IIH IIL -10 -10 2.0 0.8 +10 +10 V V A A VIS RL = 50 to VCC VCC - 0.8 300 42.5 50 SYMBOL ICC CONDITIONS All outputs enabled RL = 50 to VCC (Figure 2) 640 85 MIN TYP 140 800 100 VCC - 0.2 VCC + 0.4 1600 57.5 MAX 190 1000 115 UNITS mA MVP-P V V MVP-P CML INPUT AND OUTPUT SPECIFICATIONS 2 _______________________________________________________________________________________ +3.3V, 2.7Gbps Dual 2 AC ELECTRICAL CHARACTERISTICS 2 Crosspoint Switch MAX3840 (VCC = +3.0V to +3.6V, TA = -40C to +85C. Typical values are at VCC = +3.3V, TA = +25C, unless otherwise noted.) (Note 1) PARAMETER CML Input and Output Data Rate CML Input and Output Clock Rate CML Output Rise and Fall Time CML Output Random Jitter CML Output Deterministic Jitter CML Output Differential Skew CML Output Channel-toChannel Skew Propagation Delay from Inputto-Output tr, tf RJ DJ tskew1 tskew2 td 20% to 80% (Note 2) (Note 3) Any differential pair Any two outputs SYMBOL CONDITIONS MIN TYP 2.7 2.7 100 2 7 7 15 185 20 25 40 136 MAX UNITS Gbps GHz ps psRMS psPP ps ps ps Note 1: AC characteristics are guaranteed by design and characterization. Note 2: Measured with 100mVP-P noise (f 2MHz) on the power supply. Note 3: Deterministic jitter (DJ) is the arithmetic sum of pattern-dependent jitter and pulse width distortion. _______________________________________________________________________________________ 3 +3.3V, 2.7Gbps Dual 2 MAX3840 2 Crosspoint Switch Typical Operating Characteristics (VCC = +3.3V, TA = +25C, unless otherwise noted.) SUPPLY CURRENT vs. TEMPERATURE MAX3840 toc01 CML DIFFERENTIAL VOLTAGE CML DIFFERENTIAL VOLTAGE (mVP-P) 750 700 650 600 550 500 450 400 350 300 250 200 MAX3840 toc02 160 4 OUTPUTS ENABLED 140 SUPPLY CURRENT (mA) 120 100 80 60 40 20 0 -50 -30 -10 10 50 30 TEMPERATURE (C) 70 3 OUTPUTS ENABLED 2 OUTPUTS ENABLED 1 OUTPUT ENABLED 0 OUTPUTS ENABLED 800 90 -50 -30 -10 10 50 30 TEMPERATURE (C) 70 90 2.7Gbps EYE DIAGRAM INPUT = 223 - 1PRBS MAX3840 toc03 CHANNEL-TO-CHANNEL SKEW vs. TEMPERATURE 18 16 14 MAX3840 toc04 20 150mV/div TMIE (ps) 12 10 8 6 4 2 0 CHANNEL A -50 -30 -10 10 30 50 70 90 CHANNEL B 54ps/div TEMPERATURE (C) 4 _______________________________________________________________________________________ +3.3V, 2.7Gbps Dual 2 2 Crosspoint Switch Pin Description MAX3840 PIN 1 2 3 4 5 6 7 8 9, 24 10, 13, 16, 17, 20, 23 11 12 14 15 18 19 21 22 25 26 27 28 29 30 31 32 EP NAME ENB1 DIB1+ DIB1ENB0 SELB0 DIB0+ DIB0SELB1 GND VCC DOB0DOB0+ DOB1DOB1+ DOA1DOA1+ DOA0DOA0+ SELA1 DIA0+ DIA0SELA0 ENA0 DIA1+ DIA1ENA1 Exposed Pad FUNCTION Channel B1 Output Enable, TTL Input. A TTL low input powers down B1 output stage. Channel B1 Positive Signal Input, CML Channel B1 Negative Signal Input, CML Channel B0 Output Enable, TTL Input. A TTL low input powers down B0 output stage. Channel B0 Output Select, TTL Input. See Table 1. Channel B0 Positive Signal Input, CML Channel B0 Negative Signal Input, CML Channel B1 Output Select, TTL Input. See Table 1. Supply Ground Positive Supply Channel B0 Negative Output, CML Channel B0 Positive Output, CML Channel B1 Negative Output, CML Channel B1 Positive Output, CML Channel A1 Negative Output, CML Channel A1 Positive Output, CML Channel A0 Negative Output, CML Channel A0 Positive Output, CML Channel A1 Output Select, TTL Input. See Table 1. Channel A0 Positive Signal Input, CML Channel A0 Negative Signal Input, CML Channel A0 Output Select, TTL Input. See Table 1. Channel A0 Output Enable, TTL Input. A TTL low input powers down A0 output stage. Channel A1 Positive Signal Input, CML Channel A1 Negative Signal Input, CML Channel A1 Output Enable, TTL Input. A TTL low input powers down A1 output stage. Ground. The exposed pad must be soldered to the circuit board ground for proper electrical and thermal operation. _______________________________________________________________________________________ 5 +3.3V, 2.7Gbps Dual 2 MAX3840 Table 1. Output Routing ROUTING CONTROLS SELA0/SELB0 0 0 1 1 X SELA1/SELB1 0 1 0 1 X 2 Crosspoint Switch OUTPUT CONTROLS ENA0/ENA1 ENB0/ENB1 1 1 1 1 0 1 1 1 1 0 DIA0/DIB0 DIA0/DIB0 DIA1/DIB1 DIA1/DIB1 Power Down OUTPUT SIGNALS Signal at DOA0/DOB0 Signal at DOA1/DOB1 DIA0/DIB0 DIA1/DIB1 DIA0/DIB0 DIA1/DIB1 Power Down DIA0+ DIA0- CML 0 CML 1 DOA0+ DOA0ENA0 SELA0 CML+ 500mV MAX 320mV MIN 0 DIA1+ DIA1CML CML 1 DOA1+ DOA1ENA1 SELA1 CML- DIB0+ DIB0- CML 0 CML 1 DOB0+ DOB0ENB0 SELB0 1000mV MAX 640mV MIN 0 DIB1+ DIB1CML CML 1 DOB1+ DOB1ENB1 SELB1 (CML+) - (CML-) Figure 1. Functional Block Diagram Figure 2. CML Output Levels _______________ Detailed Description The block diagram in Figure 1 shows the MAX3840 architecture. The SELA_ and SELB_ pins control the routing of the signals through the crosspoint switch. Each output of the crosspoint switch drives a CML output driver. Each of the outputs, DOA_ and DOB_, is enabled or disabled by the respective ENA_ and ENB_ pins. CML Inputs and Outputs CML is used to simplify high-speed interfacing. Onchip input and output terminations minimize the number of external components required while improving signal integrity. The CML output signal swing is small, resulting in lower power consumption. The internal 50 input and output terminations minimize reflections and eliminate the need for external terminations. 6 _______________________________________________________________________________________ +3.3V, 2.7Gbps Dual 2 Applications Information Interfacing PECL Inputs and Outputs to the MAX3840 For information on interfacing with CML, refer to Maxim Application Note HFAN-1, Interfacing Between CML, PECL, and LVDS. 2 Crosspoint Switch Layout Techniques MAX3840 For best performance, use good high-frequency layout techniques, filter VCC supplies, and keep ground connections short. Use multiple vias where possible. Also, use controlled-impedance transmission lines to interface with the MAX3840 data inputs and outputs. ___________________ Interface Models Figure 3 shows the interface model for the CML inputs, and Figure 4 shows the model for CML outputs. VCC VCC MAX3840 VCC 50 50 DIA0+ DOA050 VCC DOA0+ 50 DIA0- MAX3840 Figure 3. CML Input Model Figure 4. CML Output Model _______________________________________________________________________________________ 7 +3.3V, 2.7Gbps Dual 2 MAX3840 2 Crosspoint Switch Chip Information TRANSISTOR COUNT: 1200 PROCESS: Bipolar (SiGe) Pin Configuration SELA0 DIA1+ DIA0+ DIA1DIA0ENA1 ENA0 SELA1 TOP VIEW 32 31 30 29 28 27 26 25 24 23 22 ENB1 DIB1+ DIB1ENB0 SELB0 DIB0+ DIB0SELB1 1 2 3 4 5 6 7 8 10 11 12 13 14 15 16 GND VCC DOA0+ DOA0VCC DOA1+ DOA1VCC * MAX3840 21 20 19 18 17 9 DOB0+ DOB1+ DOB0- DOB1- VCC VCC GND QFN* NOTE: THE EXPOSED PAD MUST BE SOLDERED TO THE SUPPLY GROUND. 8 _______________________________________________________________________________________ VCC +3.3V, 2.7Gbps Dual 2 2 Crosspoint Switch Package Information MAX3840 (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) _______________________________________________________________________________________ 32L QFN.EPS 9 +3.3V, 2.7Gbps Dual 2 MAX3840 2 Crosspoint Switch Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 10 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. |
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