EVALUATION KIT AVAILABLE MAX14950 Quad PCI Express Equalizer/Redriver General Description Features The MAX14950 is a quad equalizer/redriver designed to improve PCI Express® (PCIe) signal integrity by providing programmable input equalization at its receiver and programmable redrive circuitry. The output circuitry reestablishes deemphasis lost on the board and compensates for circuit-board loss. The device permits optimal placement of key PCIe components. The device is useful with stripline, microstrip printed circuits, and balanced 100I cable. S Optimized for Generation III (8.0GT/s) and The device is tailored for PCIe and features electrical idle and receiver detection on each channel. It is optimized for PCIe Gen III (8.0GT/s) and Gen II (5.0GT/s) data rates, while still handling Gen I (2.5GT/s). S Electrical Idle Detection The MAX14950 is available in a small, lead-free, 42-pin (3.5mm x 9.0mm) TQFN package for optimal layout and minimal space requirements. The device is specified over the 0NC to +70NC operating temperature range. Applications Servers Storage Desktop Computers/Notebook PCs Communications Switchers Generation II (5.0GT/s) with Generation I (2.5GT/s) Compatibility S Receive Detection Permits Completely Transparent, Software-Free Operation S Equalization Permits Placement of Up to 30in FR4 S PCIe Gen III (8.0GT/s)-Compliant Input/Output Return Loss S Very Low Latency: 160ps (typ) Propagation Delay S Random Jitter P 0.5psRMS (typ) S Deterministic Jitter P 10.5psP-P (typ) S Four-Level-Programmable Input Equalization S Eight-Level-Programmable Output Emphasis S On-Chip 50I Input/Output Terminations S Single +3.3V Supply Operation S ±5kV Human Body Model (HBM) Protection On All Pins S Space-Saving: 3.5mm x 9.0mm TQFN Package S Pin Compatible with MAX4950 PCIe Generation II Redriver/Equalizer Ordering Information PART TEMP RANGE PIN-PACKAGE MAX14950CTO+ 0NC to +70NC 42 TQFN-EP* +Denotes a lead(Pb)-free/RoHS-compliant package. *EP = Exposed pad. PCI Express is a registered trademark of PCI-SIG Corp. For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com. 19-5715; Rev 1; 11/12 MAX14950 Quad PCI Express Equalizer/Redriver ABSOLUTE MAXIMUM RATINGS (Voltages referenced to GND.) VCC ......................................................................... -0.3V to +4V All Other Pins (Note 1) ............................ -0.3V to (VCC + 0.3V) Continuous Current IN_P/IN_N ...................................... Q30mA Peak Current IN_P/IN_N (pulsed for 1Fs, 1% duty cycle) ..... Q100mA Continuous Power Dissipation (TA = +70NC) TQFN (derate 34.5mW/NC above +70NC) ................. 2759mW Operating Temperature Range ............................ 0NC to +70NC Storage Temperature Range .......................... -55NC to +150NC Junction Temperature......................................................+150NC Lead Temperature (soldering, 10s) ................................+300NC Soldering Temperature (reflow) ......................................+260NC Note 1:All I/O pins are clamped by internal diodes. PACKAGE THERMAL CHARACTERISTICS (Note 2) TQFN Junction-to-Ambient Thermal Resistance (qJA)...........29°C/W Junction-to-Case Thermal Resistance (qJC)..................2°C/W Note 2: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial. 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. ELECTRICAL CHARACTERISTICS (VCC = +3.0V to +3.6V, CCL = 200nF coupling capacitor on each output, RL = 50I on each output, TA = 0NC to +70NC, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25NC.) (Note 3) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 3.6 V DC PERFORMANCE Power-Supply Range Supply Current 2 VCC ICC 3.0 EN = VCC OEQ2 = GND, OEQ1 = GND, OEQ0 = GND 205 260 OEQ2 = GND, OEQ1 = GND, OEQ0 = VCC 212 270 OEQ2 = GND, OEQ1 = VCC, OEQ0 = GND 214 270 OEQ2 = GND, OEQ1 = VCC, OEQ0 = VCC 247 305 OEQ2 = VCC, OEQ1 = GND, OEQ0 = GND 213 270 OEQ2 = VCC, OEQ1 = GND, OEQ0 = VCC 263 330 OEQ2 = VCC, OEQ1 = VCC, OEQ0 = GND 276 345 OEQ2 = VCC, OEQ1 = VCC, OEQ0 = VCC 328 410 mA Maxim Integrated MAX14950 Quad PCI Express Equalizer/Redriver ELECTRICAL CHARACTERISTICS (continued) (VCC = +3.0V to +3.6V, CCL = 200nF coupling capacitor on each output, RL = 50I on each output, TA = 0NC to +70NC, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25NC.) (Note 3) PARAMETER Standby Current Differential Input Impedance Differential Output Impedance Common-Mode Resistance to GND When Input Terminations Are Not Powered Common-Mode Resistance to GND When Input Terminations Are Powered SYMBOL ISTBY ZRX-DIFFDC ZTX-DIFFDC ZRX-HIGHIMP-DC ZRX-DC Output Short-Circuit Current (Note 4) ITX-SHORT Common-Mode Delta Between Active and Idle States VTX-CMDC-ACTIVEIDLE-DELTA DC Output Offset During Active State VTXACTIVEDIFF-DC DC Output Offset During Electrical Idle Maxim Integrated VTX-IDLEDIFF-DC CONDITIONS EN = GND TYP MAX OEQ2 = GND, OEQ1 = GND, OEQ0 = GND MIN 113 150 OEQ2 = GND, OEQ1 = GND, OEQ0 = VCC 122 150 OEQ2 = GND, OEQ1 = VCC, OEQ0 = GND 125 155 OEQ2 = GND, OEQ1 = VCC, OEQ0 = VCC 150 185 OEQ2 = VCC, OEQ1 = GND, OEQ0 = GND 122 150 OEQ2 = VCC, OEQ1 = GND, OEQ0 = VCC 172 210 OEQ2 = VCC, OEQ1 = VCC, OEQ0 = GND 184 225 OEQ2 = VCC, OEQ1 = VCC, OEQ0 = VCC 237 290 UNITS mA DC 80 100 120 I DC 80 100 120 I -150mV < VIN_CM < 200mV 50 DC 20 Single-ended 90 kI 25 30 I mA 8 mV |(VOUT_P - VOUT_N)| 75 mV |(VOUT_P - VOUT_N)| 75 mV 3 MAX14950 Quad PCI Express Equalizer/Redriver ELECTRICAL CHARACTERISTICS (continued) (VCC = +3.0V to +3.6V, CCL = 200nF coupling capacitor on each output, RL = 50I on each output, TA = 0NC to +70NC, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25NC.) (Note 3) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS AC PERFORMANCE (Note 4) Differential Input Return Loss Common-Mode Input Return Loss Differential Output Return Loss Common-Mode Output Return Loss RLRX-DIFF RLRX-CM RLTX-DIFF RLTX-CM Redriver Operation Differential Input-Signal Range VRX-DIFF- Full-Swing Differential Output Voltage (No Deemphasis) VTX-DIFF- Output Deemphasis Ratio, 0dB 10 f = 1.25GHz to 2.5GHz 8 f = 2.5GHz to 4GHz 5 f = 0.05GHz to 2.5GHz 6 f = 2.5GHz to 4GHz 4 f = 0.05GHz to 1.25GHz 10 f = 1.25GHz to 2.5GHz 8 f = 2.5GHz to 4GHz 4 f = 0.05GHz to 2.5GHz 6 f = 2.5GHz to 4GHz 4 PP PP VTX-DERATIO-0dB VTX-DE- Output Deemphasis Ratio, 3.5dB f = 0.05GHz to 1.25GHz RATIO3.5dB |(VOUT_P - VOUT_N)|, OEQ2 = GND, OEQ1 = GND, OEQ0 = GND dB dB dB dB 100 1200 mVP-P 800 1300 mVP-P OEQ2 = GND, OEQ1 = GND, OEQ0 = GND, Figure 1 0 dB OEQ2 = GND, OEQ1 = GND, OEQ0 = VCC, Figure 1 3.5 dB Output Deemphasis Ratio, 6dB VTX-DERATIO-6dB OEQ2 = GND, OEQ1 = VCC, OEQ0 = GND, Figure 1 6 dB Output Deemphasis Ratio, 6dB with Higher Amplitude VTX-DE-HA- OEQ2 = GND, OEQ1 = VCC, RATIO-6dB OEQ0 = VCC, Figure 1 6 dB 3.5 dB Output Deemphasis Ratio, 3.5dB with Preshoot VTX-DEPS-RATIO3.5dB Output Deemphasis Ratio, 6dB with Preshoot VTX-DE-PS- OEQ2 = VCC, OEQ1 = GND, RATIO-6dB OEQ0 = VCC, Figure 1 6 dB Output Deemphasis Ratio, 9dB with Preshoot VTX-DE-PS- OEQ2 = VCC, OEQ1 = VCC, RATIO-9dB OEQ0 = GND, Figure 1 9 dB Output Deemphasis Ratio, 9dB with Preshoot with Higher Amplitude VTX-DE-PS- OEQ2 = VCC, OEQ1 = VCC, OEQ0 = VCC, Figure 1 9 dB INEQ1 = GND, INEQ0 = GND (Note 5) 5 dB INEQ1 = GND, INEQ0 = VCC (Note 5) 8 dB INEQ1 = VCC, INEQ0 = GND (Note 5) 12 dB Input Equalization, 5dB Input Equalization, 8dB Input Equalization, 12dB 4 HA-RATIO9dB VRX-EQ5dB VRX-EQ8dB VRX-EQ12dB OEQ2 = VCC, OEQ1 = GND, OEQ0 = GND, Figure 1 Maxim Integrated MAX14950 Quad PCI Express Equalizer/Redriver ELECTRICAL CHARACTERISTICS (continued) (VCC = +3.0V to +3.6V, CCL = 200nF coupling capacitor on each output, RL = 50I on each output, TA = 0NC to +70NC, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25NC.) (Note 3) PARAMETER Input Equalization, 16dB SYMBOL VRX-EQ16dB CONDITIONS MIN INEQ1 = VCC, INEQ0 = VCC (Note 5) TYP MAX 16 UNITS dB AC PERFORMANCE (Note 4) Output Common-Mode Voltage Swing Peak-to-Peak Propagation Delay Rise/Fall Time VTX-CMAC-PP Max(VOUT_P + VOUT_N)/2 - Min(VOUT_P + VOUT_N)/2 tPD tTX-RISEFALL 120 (Note 6) Rise/Fall Time Mismatch tTX-RFMISMATCH (Note 6) Deterministic Jitter tTX-DJ-DD K28.5 pattern, AC-coupled, RL = 50I, data rate = 8GT/s Random Jitter tTX-RJ-DD D10.2 pattern, no deemphasis, no preshoot, data rate = 8GT/s tTX-IDLEElectrical Idle Entry Delay SET-TOIDLE tTX-IDLEElectrical Idle Exit Delay Electrical Idle Detect Threshold TO-DIFFDATA 20 ps 23.5 psP-P 0.5 1.5 psRMS From input to output, D10.2 pattern, data rate = 1GT/s 5 8 ns From input to output, D10.2 pattern, data rate = 1GT/s 5 8 ns 112 175 D10.2 pattern, data rate = 1GT/s to 8GT/s VTX-RCV- ps 10.5 D10.2 pattern, data rate = 1GT/s (Note 3) Receiver Detection Pulse Amplitude 240 ps THRESH VTX-IDLEDIFF-AC-P mVP-P 5 VTX-IDLE- Output Voltage During Electrical Idle (AC) 160 100 65 112 |(VOUT_P - VOUT_N)| 20 mVP-P 600 mV Receiver Detection Pulse Width 150 ns Receiver Detection Retry Period 300 ns DETECT Voltage change in positive direction mVP-P CONTROL LOGIC Input Logic-Level Low VIL Input Logic-Level High VIH Input Logic Hysteresis VHYST Input Pulldown Resistance 0.6 1.4 RPD 200 V V 0.1 V 250 kI ±5 kV ESD PROTECTION ESD Voltage Note Note Note Note Human Body Model 3:All units are 100% production tested at TA = +70NC. Specifications for all temperature limits are guaranteed by design. 4:Guaranteed by design, unless otherwise noted. 5:Equivalent to same amount of deemphasis driving the input. 6:Rise and fall times are measured using 20% and 80% levels. Maxim Integrated 5 MAX14950 Quad PCI Express Equalizer/Redriver VLOW_P-P VHIGH_P-P DE(dB) = 20 log VHIGH_P- P VLOW_P-P Figure 1. Illustration of Output Deemphasis Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 0, OEQ1 = 0, OEQ0 = 0, DATA RATE = 5GT/s INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 0, OEQ1 = 0, OEQ0 = 1, DATA RATE = 5GT/s MAX14950 toc01 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 0, OEQ1 = 1, OEQ0 = 0, DATA RATE = 5GT/s MAX14950 toc02 600 0 -200 -400 400 400 200 200 VOLTAGE (mV) 200 VOLTAGE (mV) VOLTAGE (mV) 400 0 -200 MAX14950 toc03 600 600 0 -200 -400 -400 -600 -600 -600 -200 -150 -100 -50 0 (ps) 50 -200 -150 -100 -50 100 150 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 0, OEQ1 = 1, OEQ0 = 1, DATA RATE = 5GT/s 0 (ps) 50 -200 -150 -100 -50 100 150 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 1, OEQ1 = 0, OEQ0 = 0, DATA RATE = 5GT/s MAX14950 toc04 MAX14950 toc06 600 400 400 0 -200 200 VOLTAGE (mV) 200 VOLTAGE (mV) VOLTAGE (mV) 100 150 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 1, OEQ1 = 0, OEQ0 = 1, DATA RATE = 5GT/s 400 0 -200 -400 200 0 -200 -400 -400 -600 -600 -200 -150 -100 -50 6 50 MAX14950 toc05 600 600 0 (ps) 0 (ps) 50 100 150 -200 -150 -100 -50 0 (ps) 50 100 150 -200 -150 -100 -50 0 (ps) 50 100 150 Maxim Integrated MAX14950 Quad PCI Express Equalizer/Redriver Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 1, OEQ1 = 0, OEQ0 = 1, DATA RATE = 5GT/s INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 1, OEQ1 = 1, OEQ0 = 1, DATA RATE = 5GT/s MAX14950 toc07 MAX14950 toc08 600 600 400 200 VOLTAGE (mV) VOLTAGE (mV) 400 0 -200 200 0 -200 -400 -400 -600 -600 -200 -150 -100 -50 0 (ps) 50 100 150 -200 -150 -100 -50 INEQ1 = 0, INEQ0 = 1, VIN = 500mVP-P, OEQ2 = OEQ1 = OEQ0 = 0, 6in MICROSTRIP ON INPUT, DATA RATE = 5GT/s 400 400 200 200 VOLTAGE (mV) VOLTAGE (mV) 600 0 -200 -400 -400 -600 -600 -200 -150 -100 -50 0 (ps) 50 100 150 -200 -150 -100 -50 INEQ1 = 1, INEQ0 = 0, VIN = 500mVP-P, OEQ2 = OEQ1 = OEQ0 = 0, 18in MICROSTRIP ON INPUT, DATA RATE = 5GT/s 0 (ps) 50 400 400 200 200 0 -200 -400 -400 -600 -600 -200 -150 -100 -50 0 (ps) Maxim Integrated MAX14950 toc12 600 VOLTAGE (mV) VOLTAGE (mV) MAX14950 toc11 -200 50 100 150 100 150 INEQ1 = 1, INEQ0 = 1, VIN = 500mVP-P, OEQ2 = OEQ1 = OEQ0 = 0, 24in MICROSTRIP ON INPUT, DATA RATE = 5GT/s 600 0 100 150 MAX14950 toc10 600 -200 50 INEQ1 = 0, INEQ0 = 1, VIN = 500mVP-P, OEQ2 = OEQ1 = OEQ0 = 0, 12in MICROSTRIP ON INPUT, DATA RATE = 5GT/s MAX14950 toc09 0 0 (ps) -200 -150 -100 -50 0 (ps) 50 100 150 7 MAX14950 Quad PCI Express Equalizer/Redriver Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 0, OEQ1 = 0, OEQ0 = 1, OUTPUT AFTER 19in STRIPLINE, DATA RATE = 5GT/s INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 1, OEQ1 = 1, OEQ0 = 1, OUTPUT AFTER 19in STRIPLINE, DATA RATE = 5GT/s MAX14950 toc13 MAX14950 toc14 300 300 200 100 VOLTAGE (mV) VOLTAGE (mV) 200 0 -100 -200 100 0 -100 -200 -300 -300 -400 -200 -150 -100 -50 0 (ps) 50 -200 -150 -100 -50 100 150 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 1, OEQ1 = 1, OEQ0 = 0, OUTPUT AFTER 19in STRIPLINE, DATA RATE = 5GT/s 0 (ps) 50 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 1, OEQ1 = 0, OEQ0 = 1, OUTPUT AFTER 19in STRIPLINE, DATA RATE = 5GT/s MAX14950 toc15 MAX14950 toc16 300 250 200 200 100 VOLTAGE (mV) VOLTAGE (mV) 150 50 0 -50 -100 -150 100 0 -100 -200 -200 -250 -300 -200 -150 -100 -50 0 (ps) 50 100 150 -200 -150 -100 -50 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 0, OEQ1 = 1, OEQ0 = 1, OUTPUT AFTER 19in STRIPLINE, DATA RATE = 5GT/s 0 (ps) 50 MAX14950 toc17 MAX14950 toc18 300 200 200 100 VOLTAGE (mV) VOLTAGE (mV) 100 150 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 1, OEQ1 = 0, OEQ0 = 1, OUTPUT AFTER 19in STRIPLINE, DATA RATE = 5GT/s 300 0 -100 100 0 -100 -200 -200 -300 -300 -200 -150 -100 -50 8 100 150 0 (ps) 50 100 150 -200 -150 -100 -50 0 (ps) 50 100 150 Maxim Integrated MAX14950 Quad PCI Express Equalizer/Redriver Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 0, OEQ1 = 0, OEQ0 = 0, OUTPUT AFTER 19in STRIPLINE, DATA RATE = 5GT/s INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 0, OEQ1 = 1, OEQ0 = 0, OUTPUT AFTER 19in STRIPLINE, DATA RATE = 5GT/s MAX14950 toc20 500 200 400 150 300 100 200 VOLTAGE (mV) VOLTAGE (mV) MAX14950 toc19 250 50 0 -50 100 0 -100 -100 -200 -150 -300 -200 -400 -250 -500 -200 -150 -100 -50 0 (ps) 50 -200 -150 -100 -50 100 150 0 (ps) 50 100 150 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 0, OEQ1 = 0, OEQ0 = 1, DATA RATE = 8GT/s INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 0, OEQ1 = 0, OEQ0 = 0, DATA RATE = 8GT/s MAX14950 toc21 MAX14950 toc22 600 600 400 200 VOLTAGE (mV) VOLTAGE (mV) 400 0 -200 -400 200 0 -200 -400 -600 -600 -100 -50 0 (ps) 50 -100 100 -50 0 (ps) 50 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 0, OEQ1 = 1, OEQ0 = 1, DATA RATE = 8GT/s INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 0, OEQ1 = 1, OEQ0 = 0, DATA RATE = 8GT/s MAX14950 toc24 MAX14950 toc23 600 100 600 400 200 VOLTAGE (mV) VOLTAGE (mV) 400 0 -200 200 0 -200 -400 -400 -600 -600 -100 Maxim Integrated -50 0 (ps) 50 100 -100 -50 0 (ps) 50 100 9 MAX14950 Quad PCI Express Equalizer/Redriver Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 1, OEQ1 = 0, OEQ0 = 0, DATA RATE = 8GT/s INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 1, OEQ1 = 0, OEQ0 = 1, DATA RATE = 8GT/s MAX14950 toc25 600 MAX14950 toc26 600 400 200 VOLTAGE (mV) VOLTAGE (mV) 400 0 -200 200 0 -200 -400 -400 -600 -600 -100 -50 0 (ps) 50 100 -100 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 1, OEQ1 = 1, OEQ0 = 0, DATA RATE = 8GT/s -50 0 (ps) 50 100 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 1, OEQ1 = 1, OEQ0 = 1, DATA RATE = 8GT/s MAX14950 toc27 MAX14950 toc28 800 600 600 400 200 VOLTAGE (mV) VOLTAGE (mV) 400 0 -200 200 0 -200 -400 -400 -600 -600 -100 -50 0 (ps) 50 100 -100 INEQ1 = 0, INEQ0 = 0, VIN = 500mVP-P, OEQ2 = OEQ1 = OEQ0 = 0, 6in MICROSTRIP ON INPUT, DATA RATE = 8GT/s -50 0 (ps) 50 INEQ1 = 0, INEQ0 = 1, VIN = 500mVP-P, OEQ2 = OEQ1 = OEQ0 = 0, 12in MICROSTRIP ON INPUT, DATA RATE = 8GT/s 400 400 200 200 -200 0 -200 -400 -400 -600 -600 -100 10 MAX14950 toc30 600 VOLTAGE (mV) VOLTAGE (mV) MAX14950 toc29 600 0 -50 0 (ps) 50 100 100 -100 -50 0 (ps) 50 100 Maxim Integrated MAX14950 Quad PCI Express Equalizer/Redriver Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) INEQ1 = 1, INEQ0 = 0, VIN = 500mVP-P, OEQ2 = OEQ1 = OEQ0 = 0, 18in MICROSTRIP ON INPUT, DATA RATE = 8GT/s INEQ1 = 1, INEQ0 = 1, VIN = 500mVP-P, OEQ2 = OEQ1 = OEQ0 = 0, 24in MICROSTRIP ON INPUT, DATA RATE = 8GT/s MAX14950 toc32 600 600 400 400 VOLTAGE (mV) VOLTAGE (mV) MAX14950 toc31 200 0 -200 200 0 -200 -400 -400 -600 -600 -100 -50 0 (ps) 50 100 -100 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 0, OEQ1 = 0, OEQ0 = 1, OUTPUT AFTER 19in STRIPLINE, DATA RATE = 8GT/s -50 0 (ps) 50 100 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 1, OEQ1 = 1, OEQ0 = 1, OUTPUT AFTER 19in STRIPLINE, DATA RATE = 8GT/s MAX14950 toc33 MAX14950 toc34 300 300 200 VOLTAGE (mV) VOLTAGE (mV) 200 10 0 -100 10 0 -100 -200 -200 -300 -300 -100 -50 0 (ps) 50 100 -100 -50 0 (ps) 50 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 1, OEQ1 = 0, OEQ0 = 1, OUTPUT AFTER 19in STRIPLINE, DATA RATE = 8GT/s INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 1, OEQ1 = 1, OEQ0 = 0, OUTPUT AFTER 19in STRIPLINE, DATA RATE = 8GT/s MAX14950 toc36 MAX14950 toc35 300 250 200 200 100 VOLTAGE (mV) VOLTAGE (mV) 150 50 0 -50 10 0 -100 -100 -150 -200 -200 -250 -300 -100 Maxim Integrated 100 -50 0 (ps) 50 100 -100 -50 0 (ps) 50 100 11 MAX14950 Quad PCI Express Equalizer/Redriver Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 1, OEQ1 = 1, OEQ0 = 0, OUTPUT AFTER 19in STRIPLINE, DATA RATE = 8GT/s INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 1, OEQ1 = 0, OEQ0 = 0, OUTPUT AFTER 19in STRIPLINE, DATA RATE = 8GT/s MAX14950 toc37 MAX14950 toc38 300 300 200 VOLTAGE (mV) VOLTAGE (mV) 200 10 0 -100 10 0 -100 -200 -200 -300 -300 -100 -50 0 (ps) 50 -100 100 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 0, OEQ1 = 1, OEQ0 = 0, OUTPUT AFTER 19in STRIPLINE, DATA RATE = 8GT/s -50 0 (ps) 50 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, 0EQ2 = 0, OEQ1 = 0, OEQ0 = 0, OUTPUT AFTER 19in STRIPLINE, DATA RATE = 8GT/s 200 400 150 300 100 200 0 -50 100 0 -100 -100 -200 -150 -300 -200 -400 -250 -500 -100 12 MAX14950 toc40 500 VOLTAGE (mV) VOLTAGE (mV) MAX14950 toc39 250 50 -50 0 (ps) 50 100 100 -100 -50 0 (ps) 50 100 Maxim Integrated MAX14950 Quad PCI Express Equalizer/Redriver Pin Configuration VCC GND OUT3N OUT3P GND OUT2N OUT2P GND VCC GND OUT1N OUT1P GND OUT0N OUT0P GND VCC TOP VIEW 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 OEQ0 *EP 20 OEQ1 MAX14950 OEQ2 41 I.C. 42 19 INEQ0 18 INEQ1 8 9 VCC IN0P IN0N GND IN1P IN1N GND VCC 10 11 12 13 14 15 16 17 GND 7 IN3N 6 IN3P 5 GND 4 IN2N 3 IN2P 2 GND 1 GND + VCC EN 39 RXDET 40 TQFN *CONNECT EXPOSED PAD (EP) TO GND. Pin Description PIN NAME FUNCTION 1, 9, 17, 22, 30, 38 VCC Power-Supply Input. Bypass VCC to GND with 1FF and 0.1FF capacitors in parallel as close as possible to the device. 2, 5, 8, 10, 13, 16, 23, 26, 29, 31, 34, 37 GND Ground 3 IN0P Noninverting Input, Channel 0 4 IN0N Inverting Input, Channel 0 6 IN1P Noninverting Input, Channel 1 7 IN1N Inverting Input, Channel 1 11 IN2P Noninverting Input, Channel 2 12 IN2N Inverting Input, Channel 2 14 IN3P Noninverting Input, Channel 3 15 IN3N Inverting Input, Channel 3 18 INEQ1 Input Equalization Control MSB. INEQ1 has a 250kI (typ) internal pulldown resistor. 19 INEQ0 Input Equalization Control LSB. INEQ0 has a 250kI (typ) internal pulldown resistor. 20 OEQ1 Output Deemphasis Control Bit 1. OEQ1 has a 250kI (typ) internal pulldown resistor. 21 OEQ0 Output Deemphasis Control LSB. OEQ0 has a 250kI (typ) internal pulldown resistor. 24 OUT3N Inverting Output, Channel 3 25 OUT3P Noninverting Output, Channel 3 27 OUT2N Inverting Output, Channel 2 28 OUT2P Noninverting Output, Channel 2 32 OUT1N Inverting Output, Channel 1 33 OUT1P Noninverting Output, Channel 1 Maxim Integrated 13 MAX14950 Quad PCI Express Equalizer/Redriver Pin Description (continued) PIN NAME 35 OUT0N Inverting Output, Channel 0 FUNCTION 36 OUT0P Noninverting Output, Channel 0 39 EN Enable Input. Drive EN low for standby mode. Drive EN high for normal mode. EN has a 250kI (typ) internal pulldown resistor. 40 RXDET Receiver Detection Control Bit. Drive RXDET high to initiate receiver detection. Drive RXDET low for normal mode. RXDET has a 250kI (typ) internal pulldown resistor. 41 OEQ2 Output Deemphasis Control MSB. OEQ2 has a 250kI (typ) internal pulldown resistor. 42 I.C. Internally Connected — EP Exposed Pad. Internally connected to GND. Connect EP to a large ground plane to maximize thermal performance as well as good ground conductivity to the device. Functional Diagram MAX14950 IN0P OUT0P IN0N OUT0N IN1P OUT1P IN1N OUT1N IN2P OUT2P IN2N OUT2N IN3P OUT3P IN3N OUT3N DETECTION AND CONTROL CIRCUIT EN RXDET 14 INEQ[0:1] OEQ[0:2] Maxim Integrated MAX14950 Quad PCI Express Equalizer/Redriver Detailed Description The MAX14950 quad equalizer/redriver is designed to support Gen III (8.0GT/s), Gen II (5.0GT/s), and Gen I (2.5GT/s) PCIe data rates. The device contains four identical drivers with electrical idle/receive detect on each lane and equalization/deemphasis/preshoot to compensate for circuit-board loss. Programmable input equalization circuitry reduces deterministic jitter, improving signal integrity. The device output features a programmable output deemphasis/preshoot, permitting optimal placement of key PCIe components and longer runs of stripline, microstrip, or cable. Programmable Input Equalization Programmable input equalization is controlled by two bits: INEQ1 and INEQ0 (Table 1). Table 1. Input Equalization INEQ1 INEQ0 INPUT EQUALIZATION (dB) 0 0 5 0 1 8 1 0 12 1 1 16 Programmable Output Deemphasis/ Preshoot Programmable output deemphasis is controlled by three bits: OEQ2, OEQ1, and OEQ0 for deemphasis/preshoot ratios of 0dB, 3.5dB, 6dB, and 9dB (Table 2). Table 2. Output Deemphasis/Preshoot OUTPUT DEEMPHASIS/ PRESHOOT RATIO (dB) OEQ2 OEQ1 OEQ0 0 0 0 0 0 0 1 3.5 0 1 0 6 0 1 1 6 (Peak-to-Peak Swing is 1.2V) 1 0 0 3.5 1 0 1 6 1 1 0 9 (Peak-to-Peak Swing is 0.9V) 1 1 1 9 (Peak-to-Peak Swing is 1.0V) Maxim Integrated Receiver Detection The device features receiver detection on each channel. Upon initial power-up, if EN is high, receiver detection initializes. Receiver detection can also be initiated on a rising or falling edge of the RXDET input when EN is high. During this time, the device remains in low-power standby mode and the outputs are disabled, despite the logic-high state of EN. Until a channel has detected a receiver, the receiver detection repeats indefinitely on each channel. If a channel detects a receiver, the other channels are limited to retries for 100ms (typ). For each channel upon receiver detection, input common-mode termination and electrical idle detection are enabled (Table 3). Electrical Idle Detection The device features electrical idle detection to prevent unwanted noise from being redriven at the output. When the device detects that the differential input has fallen below the VTX-IDLE-THRESH low limit, it squelches the output. For differential input signals that are above VTXIDLE-THRESH high limit, the device turns on the output and redrives the signal. There is little variation in output common-mode voltage between electrical idle and redrive modes. Table 3. Receiver Detection Input Function RXDET EN DESCRIPTION X 0 Receiver detection is inactive. X 1 Following a rising edge of EN signal, indefinite retry until receiver detects at least one channel. Retries stop after 100ms (typ) if any channel receiver is detected. Rising/Falling Edge 1 Initiates receiver detection. X = Don’t care. 15 MAX14950 Quad PCI Express Equalizer/Redriver MAIN BOARD REMOTE BOARD MIDPLANE Tx MAX14950 Rx 4 DIFFERENTIAL PAIRS PCIe PCIe Rx MAX14950 Tx 4 DIFFERENTIAL PAIRS CONNECTORS Figure 2. Typical Application Diagram Applications Information Figure 2 shows a typical application with two MAX14950s, both residing on the main board, with input and output equalization set individually for optimal performance. The MAX14950 Rx equalizer is set to receive a degraded signal coming from a remote board through two sets of connectors and a midplane stripline. The output of the Rx section has little or no output equalization. The Tx section takes a high-quality signal and provides boost to the output (deemphasis). Layout Circuit-board layout and design can significantly affect the performance of the device. Use good, high-frequency design techniques, including minimizing ground inductance and using controlled-impedance transmission lines on data signals. Power-supply decoupling should also be placed as close as possible to VCC. Always connect VCC to a power plane. It is recommended to run receive and transmit signals on different layers to minimize crosstalk. Exposed-Pad Package The exposed-pad, 42-pin TQFN package incorporates features that provide a very low-thermal-resistance path for heat removal from the IC. The exposed pad on the device must be soldered to the circuit-board ground 16 plane for proper thermal performance and good ground connectivity. For more information on exposed-pad packages, refer to Application Note 862: HFAN-08.1: Thermal Considerations of QFN and Other ExposedPaddle Packages. Power-Supply Sequencing Caution: Do not exceed the absolute maximum ratings because stresses beyond the listed ratings may cause permanent damage to the device. Proper power-supply sequencing is recommended for all devices. Always apply GND then VCC before applying signals, especially if the signal is not current limited. Chip Information PROCESS: BiCMOS Package Information For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 42 TQFN-EP T423590+1 21-0181 90-0078 Maxim Integrated MAX14950 Quad PCI Express Equalizer/Redriver Revision History REVISION NUMBER REVISION DATE 0 12/10 Initial release 1 11/12 Removed military application information; updated Electrical Characteristics table, Typical Operating Characteristics, Pin Configuration, and Pin Description. DESCRIPTION PAGES CHANGED — 1, 3–16 Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000 © 2012 Maxim Integrated Products, Inc. 17 Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.