MAX14955 Single-Lane PCIe Gen III Redriver with Equalization and Extended Temperature Operation General Description The MAX14955 dual equalizer/redriver improves PCI Express® (PCIe) signal integrity by providing programmable input equalization. This feature reduces deterministic jitter and redrives circuitry to reestablish deemphasis, which compensates for circuit-board loss at high frequencies. The device permits optimal placement of key PCIe components and allows for longer runs of stripline, microstrip, or cable. The device contains two identical channels capable of equalizing PCIe Gen III (8GT/s), Gen II (5GT/s), and Gen I (2.5GT/s) signals and features electrical idle and receiver detection. The MAX14955 is available in a small, 40-pin, 5.0mm x 5.0mm TQFN package with flow-through traces for optimal layout and minimal space requirements. The device is specified over the -40°C to +85°C extending operating temperature range. Applications ● ● ● ● ● ● Benefits and Features ● Fully Integrated for Ease of Use and Design Flexibility • Optimized for PCIe Gen III (8.0GT/s), Gen II (5.0GT/s), Gen I (2.5 GT/s) Compatible • Four Levels of Input Equalization up to 16dB • Eight Levels of Output Deemphasis up to 9dB ● High Level of Performance to Overcome Noise in Lossy Channels • Random Jitter: 0.5psRMS (typ) • Deterministic Jitter: 7psP-P (typ) • Equalization Permits Placement Up to 30in FR4 ● Robust Solution for Harsh Environments • Industrial Temperature Rated: -40°C to +85°C • ±4kV Human Body Model (HBM) Protection on All Pins • Housed in a Flow-Through (5mm x 5mm) TQFN Package for Resistance to Vibration/Shocks Ordering Information appears at end of data sheet. Industrial/Embedded PCs Computer on Modules Carrier Boards Test Equipment Rack Server Industrial PCs Medical Equipment For related parts and recommended products to use with this part, refer to www.maximintegrated.com/MAX14955.related. Typical Operating Circuit REMOTE BOARD MAIN BOARD MIDPLANE Tx SINGLE DIFFERENTIAL PAIR Rx MAX14955 PCIe PCIe Rx SINGLE DIFFERENTIAL PAIR CONNECTORS PCI Express is a registered service mark of PCI-SIG Corporation. 19-6640; Rev 0; 3/13 Tx MAX14955 Single-Lane PCIe Gen III Redriver with Equalization and Extended Temperature Operation Absolute Maximum Ratings Continuous Power Dissipation (TA = +70°C) TQFN (derate 35.7mW/°C above +70°C)..................2857mW Operating Temperature Range............................ -40°C to +85°C Junction Temperature Range............................ -40°C to +150°C Storage Temperature Range............................. -65°C to +150°C Lead Temperature (soldering, 10s).................................. +300°C Soldering Temperature (reflow)........................................+260°C (Voltages referenced to GND.) VCC........................................................................-0.3V to +4.0V All Other Pins (Note 1).............................. -0.3V to (VCC + 0.3V) Continuous Current IN_P, IN_M, OUT_P, OUT_M............................................................±30mA Peak Current IN_P, IN_M, OUT_P, OUT_M (pulsed for 1µs, 1% duty cycle)...................................±100mA Note 1: All I/O pins are clamped by internal diodes. 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. Package Thermal Characteristics (Note 2) TQFN Junction-to-Ambient Thermal Resistance (BJA).......... 28NC/W Junction-to-Case Thermal Resistance (BJC)..................2NC/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. Electrical Characteristics (VCC = +3.0V to +3.6V, CCL = 200nF coupling capacitor on each output, RL = 50Ω on each output, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25°C.) (Note 3) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 3.0 V DC PERFORMANCE Power-Supply Range Supply Current www.maximintegrated.com VCC ICC EN = VCC 3.3 3.6 OEQ_2 = OEQ_1 = OEQ_0 = GND 102 135 OEQ_2 = OEQ_1 = GND, OEQ_0 = VCC 106 140 OEQ_2 = OEQ_0 = GND, OEQ_1 = VCC 107 140 OEQ_2 = GND, OEQ_1 = OEQ_0 = VCC 125 160 OEQ_2 = VCC, OEQ_1 = OEQ_0 = GND 106 140 OEQ_2 = OEQ_0 = VCC, OEQ_1 = GND 132 170 OEQ_2 = OEQ_1 = VCC, OEQ_0 = GND 140 180 OEQ_2 = OEQ_1 = OEQ_0 = VCC 165 210 mA Maxim Integrated │ 2 MAX14955 Single-Lane PCIe Gen III Redriver with Equalization and Extended Temperature Operation Electrical Characteristics (continued) (VCC = +3.0V to +3.6V, CCL = 200nF coupling capacitor on each output, RL = 50Ω on each output, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25°C.) (Note 3) PARAMETER Standby Current SYMBOL ISTBY Differential Input Impedance ZRX-DIFF- Differential Output Impedance ZTX-DIFF- Common-Mode Resistance to GND, Input Termination Not Powered Common-Mode Resistance to GND, Input Termination Powered Output Short-Circuit Current Common-Mode Delta, Between Active and Idle States DC Output Offset, During Active State DC Output Offset, During Electrical Idle www.maximintegrated.com DC DC ZRX-HIGHIMP-DC CONDITIONS EN = GND TYP MAX OEQ_2 = OEQ_1 = OEQ_0 = GND 57 80 OEQ_2 = OEQ_1 = GND, OEQ_0 = VCC 61 85 OEQ_2 = OEQ_0 = GND, OEQ_1 = VCC 62 85 OEQ_2 = GND, OEQ_1 = OEQ_0 = VCC 75 100 OEQ_2 = VCC, OEQ_1 = OEQ_0 = GND 62 80 OEQ_2 = OEQ_0 = VCC, OEQ_1 = GND 85 110 OEQ_2 = OEQ_1 = VCC, OEQ_0 = GND 92 120 OEQ_2 = OEQ_1 = OEQ_0 = VCC 120 150 100 120 Ω DC 80 100 120 Ω -150mV ≤ VIN_CM ≤ +200mV 50 20 Single-ended (Note 4) DIFF-DC kΩ 25 30 90 Ω mA 100 mV |(VOUT_P - VOUT_M)| 65 mV |(VOUT_P - VOUT_M)| 65 mV ACTIVE-IDLEDELTA VTX-IDLE- mA 80 VTX-CM-DC- VTXACTIVEDIFF-DC UNITS DC ZRX-DC ITX-SHORT MIN Maxim Integrated │ 3 MAX14955 Single-Lane PCIe Gen III Redriver with Equalization and Extended Temperature Operation Electrical Characteristics (continued) (VCC = +3.0V to +3.6V, CCL = 200nF coupling capacitor on each output, RL = 50Ω on each output, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25°C.) (Note 3) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS AC PERFORMANCE (Note 4) Input Return Loss, Differential RLRX-DIFF Input Return Loss, Common Mode RLRX-CM Output Return Loss, Differential RLTX-DIFF Output Return Loss, Common Mode RLTX-CM Redriver-Operation Differential Input-Signal Range VRX-DIFF- Full-Swing Differential Output Voltage (No Deemphasis) VTX-DIFF- Output Deemphasis Ratio, 0dB Output Deemphasis Ratio, 3.5dB Output Deemphasis Ratio, 6dB Output Deemphasis Ratio, 6dB with Higher Amplitude f = 0.05GHz to 1.25GHz 9 dB f = 1.25GHz to 2.5GHz 8 dB f = 2.5GHz to 4GHz 5 dB f = 0.05GHz to 2.5GHz 6 dB f = 2.5GHz to 4GHz 4 dB f = 0.05GHz to 1.25GHz 10 dB f = 1.25GHz to 2.5GHz 8 dB f = 2.5GHz to 4GHz 4 dB f = 0.05GHz to 2.5GHz 6 dB f = 2.5GHz to 4GHz 4 dB 100 PP PP 2 x |(VOUT_P - VOUT_M)|, OEQ_2 = OEQ_1 = OEQ_0 = GND VTX-DERATIO-0dB OEQ_2 = OEQ_1 = OEQ_0 = GND, Figure 1 800 1000 1200 mVP-P 1400 mVP-P 0 dB VTX-DERATIO-3.5dB OEQ_2 = OEQ_1 = GND, OEQ_0 = VCC, Figure 1 3.5 dB VTX-DERATIO-6dB OEQ_2 = OEQ_0 = GND, OEQ_1 = VCC, Figure 1 6 dB VTX-DE-HA- OEQ_2 = GND, OEQ_1 = OEQ_0 = VCC, RATIO-6dB Figure 1 6 dB 3.5 dB Output Deemphasis Ratio, 3.5dB VTX-DE-PS- OEQ_2 = VCC, OEQ_1 = OEQ_0 = GND, with Preshoot RATIO-3.5dB Figure 1 Output Deemphasis Ratio, 6dB with Preshoot VTX-DE-PS- OEQ_2 = OEQ_0 = VCC, OEQ_1 = GND, RATIO-6dB Figure 1 6 dB Output Deemphasis Ratio, 9dB with Preshoot VTX-DE-PS- OEQ_2 = OEQ_1 = VCC, OEQ_0 = GND, RATIO-9dB Figure 1 9 dB Output Deemphasis Ratio, 9dB with Preshoot and Higher Amplitude VTX-DE-PS- OEQ_2 = OEQ_1 = OEQ_0 = VCC, Figure 1 9 dB Input Equalization, 5dB VRX-EQ-5dB INEQ_1 = INEQ_0 = GND (Note 5) 5 dB www.maximintegrated.com HA-RATIO9dB Maxim Integrated │ 4 MAX14955 Single-Lane PCIe Gen III Redriver with Equalization and Extended Temperature Operation Electrical Characteristics (continued) (VCC = +3.0V to +3.6V, CCL = 200nF coupling capacitor on each output, RL = 50Ω on each output, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25°C.) (Note 3) PARAMETER Input Equalization, 8dB SYMBOL VRX-EQ- Input Equalization, 16dB VRX-EQ- Propagation Delay Rise/Fall Time Rise/Fall Time Mismatch MIN VRX-EQ-8dB INEQ_1 = GND, INEQ_0 = VCC (Note 5) Input Equalization, 12dB Output Common-Mode Voltage CONDITIONS 12dB 16dB TYP dB INEQ_1 = VCC, INEQ_0 = GND (Note 5) 12 dB INEQ_1 = INEQ_0 = VCC (Note 5) 16 dB tPD FALL tTX-RFMISMATCH UNITS 8 VTX-CM-AC- MAX(VOUT_P + VOUT_M)/2 - MIN(VOUT_P + VOUT_M)/2 PP tTX-RISE- MAX 120 (Note 6) 160 100 mVP-P 240 ps 20 ps (Note 6) 20 ps Deterministic Jitter tTX-DJ-DD K28.5 pattern, AC-coupled, RL = 50I, no deemphasis, no preshoot, data rate = 8GT/s 7 23.5 psP-P Random Jitter tTX-RJ-DD D10.2 pattern, no deemphasis, no preshoot, data rate = 8GT/s 0.5 1.5 psRMS Electrical Idle Entry Delay Electrical Idle Exit Delay From input to output, D10.2 pattern, data SET-TO-IDLE rate = 1GT/s tTX-IDLE- tTX-IDLETO-DIFFDATA Electrical Idle Detect Threshold VTX-IDLE- Output Voltage During Electrical Idle (AC) VTX-IDLEDIFF-AC-P Receiver-Detect Pulse Amplitude VTX-RCV- THRESH From input to output, D10.2 pattern, data rate = 1GT/s D10.2 pattern, data rate = 1GT/s (Note 3) 50 D10.2 pattern, data rate = 1GT/s to 8GT/s 5 ns 5 ns 112 190 mVP-P 112 |(VOUT_P - VOUT_M)| 20 600 mV Receiver-Detect Pulse Width 100 ns Receiver-Detect Retry Period 200 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 375 kΩ ±4 kV ESD PROTECTION ESD Voltage www.maximintegrated.com Human Body Model (HBM) Maxim Integrated │ 5 MAX14955 Single-Lane PCIe Gen III Redriver with Equalization and Extended Temperature Operation Electrical Characteristics (continued) (VCC = +3.0V to +3.6V, CCL = 200nF coupling capacitor on each output, RL = 50Ω on each output, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25°C.) (Note 3) Note 3: All devices are 100% production tested at TA = +85NC. Specifications over operating temperature range are guaranteed by design. Note 4: Guaranteed by design, unless otherwise noted. Note 5: Equivalent to same amount of deemphasis driving the input. Note 6: Rise and fall times are measured using 20% and 80% levels. VLOW_P-P VHIGH_P-P DE(dB) = 20 log VHIGH_P- P VLOW_P-P Figure 1. Illustration of Output Deemphasis www.maximintegrated.com Maxim Integrated │ 6 MAX14955 Single-Lane PCIe Gen III Redriver with Equalization and Extended Temperature Operation Typical Operating Characteristics (VCC = +3.3V, TA = +25NC, unless otherwise noted.) 400 VOLTAGE (mV) 200 0 -200 -400 200 400 0 -200 -200 -150 -100 -50 0 50 -600 100 150 200 0 -200 -400 -400 -600 -200 -150 -100 -50 0 50 -600 100 150 -200 -150 -100 -50 0 50 100 150 TIME (ps) TIME (ps) INEQ0 = INEQ1 = 0, VIN = 200mVP-P, OEQ0 = 1, OEQ1 = 1, OEQ2 = 0, DATA RATE = 5GT/s INEQ0 = INEQ1 = 0, VIN = 200mVP-P, OEQ0 = 0, OEQ1 = 0, OEQ2 = 1, DATA RATE = 5GT/s INEQ0 = INEQ1 = 0, VIN = 200mVP-P, OEQ0 = 1, OEQ1 = 0, OEQ2 = 1, DATA RATE = 5GT/s 400 200 0 -200 -400 200 600 400 VOLTAGE (mV) VOLTAGE (mV) 400 MAX14955 toc05 MAX14955 toc04 600 0 -200 MAX14955 toc06 TIME (ps) 600 VOLTAGE (mV) 600 VOLTAGE (mV) 400 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, OEQ0 = 0, OEQ1 = 1, OEQ2 = 0, DATA RATE = 5GT/s MAX14955 toc02 600 MAX14955 toc01 600 VOLTAGE (mV) INEQ0 = INEQ1 = 0, VIN = 200mVP-P, OEQ0 = 1, OEQ1 = 0, OEQ2 = 0, DATA RATE = 5GT/s MAX14955 toc03 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, OEQ0 = 0, OEQ1 = 0, OEQ2 = 0, DATA RATE = 5GT/s 200 0 -200 -400 -400 -600 -600 -200 -150 -100 -50 0 TIME (ps) www.maximintegrated.com 50 100 150 -600 -200 -150 -100 -50 0 TIME (ps) 50 100 150 -200 -150 -100 -50 0 50 100 150 TIME (ps) Maxim Integrated │ 7 MAX14955 Single-Lane PCIe Gen III Redriver with Equalization and Extended Temperature Operation Typical Operating Characteristics (continued) (VCC = +3.3V, TA = +25NC, unless otherwise noted.) 400 0 -200 400 0 -200 -400 -400 -200 -150 -100 -50 0 50 100 150 200 0 -200 -400 -600 -600 -600 -200 -150 -100 -50 0 50 100 150 -200 -150 -100 -50 0 50 100 150 INEQ0 = 1, INEQ1 = 0, VIN = 500mVP-P, OEQ0 = OEQ1 = OEQ2 = 0, 12in MICROSTRIP ON INPUT, DATA RATE = 5GT/s INEQ0 = 0, INEQ1 = 1, VIN = 500mVP-P, OEQ0 = OEQ1 = OEQ2 = 0, 18in MICROSTRIP ON INPUT, DATA RATE = 5GT/s INEQ0 = 1, INEQ1 = 1, VIN = 500mVP-P, OEQ0 = OEQ1 = OEQ2 = 0, 24in MICROSTRIP ON INPUT, DATA RATE = 5GT/s VOLTAGE (mV) 200 400 0 -200 200 600 400 VOLTAGE (mV) 400 600 0 -200 200 0 -200 -400 -400 -400 -600 -600 -600 -200 -150 -100 -50 0 TIME (ps) www.maximintegrated.com 50 100 150 -200 -150 -100 -50 0 TIME (ps) 50 100 150 MAX14950A toc12 TIME (ps) MAX14950A toc11 TIME (ps) MAX14950A toc10 TIME (ps) 600 VOLTAGE (mV) 200 600 VOLTAGE (mV) 200 600 VOLTAGE (mV) VOLTAGE (mV) 400 INEQ0 = 1, INEQ1 = 0, VIN = 500mVP-P, OEQ0 = OEQ1 = OEQ2 = 0, 6in MICROSTRIP ON INPUT, DATA RATE = 5GT/s MAX14950A toc09 MAX14955 toc07 600 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, OEQ0 = 1, OEQ1 = 1, OEQ2 = 1, DATA RATE = 5GT/s MAX14955 toc08 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, OEQ0 = 0, OEQ1 = 1, OEQ2 = 1, DATA RATE = 5GT/s -200 -150 -100 -50 0 50 100 150 TIME (ps) Maxim Integrated │ 8 MAX14955 Single-Lane PCIe Gen III Redriver with Equalization and Extended Temperature Operation Typical Operating Characteristics (continued) (VCC = +3.3V, TA = +25NC, unless otherwise noted.) DATA RATE = 5Gbps, OUTPUT AFTER 19in STRIPLINE, INEQ_1 = 0, VIN = 200mVP-P 200 0 -100 -200 100 200 150 VOLTAGE (mV) VOLTAGE (mV) 100 250 MAX14955 toc14 200 0 -100 0 50 100 150 -100 -250 -200 -150 -100 -50 0 50 -200 -150 -100 -50 100 150 0 50 100 150 TIME (ps) TIME (ps) TIME (ps) DATA RATE = 5Gbps, OUTPUT AFTER 19in STRIPLINE, INEQ_1 = 0, VIN = 200mVP-P DATA RATE = 5Gbps, OUTPUT AFTER 19in STRIPLINE, INEQ_1 = 0, VIN = 200mVP-P DATA RATE = 5Gbps, OUTPUT AFTER 19in STRIPLINE, INEQ_1 = 0, VIN = 200mVP-P VOLTAGE (mV) 100 200 0 -100 100 0 -100 -200 -150 -100 -50 0 TIME (ps) www.maximintegrated.com 50 100 150 100 0 -100 -300 -300 -300 200 -200 -200 -200 300 VOLTAGE (mV) 200 MAX14955 toc17 300 MAX14955 toc16 300 VOLTAGE (mV) 0 -50 -200 -300 -200 -150 -100 -50 50 -150 -200 -300 100 MAX14955 toc18 VOLTAGE (mV) 300 MAX14955 toc13 300 DATA RATE = 5Gbps, OUTPUT AFTER 19in STRIPLINE, INEQ_1 = 0, VIN = 200mVP-P MAX14955 toc15 DATA RATE = 5Gbps, OUTPUT AFTER 19in STRIPLINE, INEQ_1 = 0, VIN = 200mVP-P -200 -150 -100 -50 0 TIME (ps) 50 100 150 -200 -150 -100 -50 0 50 100 150 TIME (ps) Maxim Integrated │ 9 MAX14955 Single-Lane PCIe Gen III Redriver with Equalization and Extended Temperature Operation Typical Operating Characteristics (continued) (VCC = +3.3V, TA = +25NC, unless otherwise noted.) 300 50 0 -50 200 600 400 VOLTAGE (mV) 100 400 VOLTAGE (mV) 100 0 -100 200 0 -200 -100 -200 -150 -300 -400 -200 -400 -250 -500 -600 -200 -150 -100 -50 0 50 -200 -150 -100 -50 100 150 0 50 100 150 -100 -50 0 50 100 TIME (ps) TIME (ps) INEQ0 = INEQ1 = 0, VIN = 200mVP-P, OEQ0 = 1, OEQ1 = 0, OEQ2 = 0, DATA RATE = 8GT/s INEQ0 = INEQ1 = 0, VIN = 200mVP-P, OEQ0 = 0, OEQ1 = 1, OEQ2 = 0, DATA RATE = 8GT/s INEQ0 = INEQ1 = 0, VIN = 200mVP-P, OEQ0 = 1, OEQ1 = 1, OEQ2 = 0, DATA RATE = 8GT/s 600 MAX14955 toc22 400 VOLTAGE (mV) 200 400 0 -200 200 0 -200 -400 -400 -600 -600 -100 -50 0 TIME (ps) www.maximintegrated.com 50 100 600 400 VOLTAGE (mV) 600 MAX14955 toc24 TIME (ps) MAX14955 toc23 VOLTAGE (mV) 150 MAX14955 toc20 200 VOLTAGE (mV) 500 MAX14955 toc19 250 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, OEQ0 = 0, OEQ1 = 0, OEQ2 = 0, DATA RATE = 8GT/s DATA RATE = 5Gbps, OUTPUT AFTER 19in STRIPLINE, INEQ_1 = 0, VIN = 200mVP-P MAX14955 toc21 DATA RATE = 5Gbps, OUTPUT AFTER 19in STRIPLINE, INEQ_1 = 0, VIN = 200mVP-P 200 0 -200 -400 -600 -100 -50 0 TIME (ps) 50 100 -100 -50 0 50 100 TIME (ps) Maxim Integrated │ 10 MAX14955 Single-Lane PCIe Gen III Redriver with Equalization and Extended Temperature Operation Typical Operating Characteristics (continued) (VCC = +3.3V, TA = +25NC, unless otherwise noted.) 400 0 -200 600 400 VOLTAGE (mV) 200 600 VOLTAGE (mV) 200 0 -200 -400 -400 0 50 100 -100 -50 0 50 100 -100 -50 0 50 100 TIME (ps) TIME (ps) INEQ0 = INEQ1 = 0, VIN = 200mVP-P, OEQ0 = 1, OEQ1 = 1, OEQ2 = 1, DATA RATE = 8GT/s INEQ0 = 0, INEQ1 = 0, VIN = 500mVP-P, OEQ0 = OEQ1 = OEQ2 = 0, 6in MICROSTRIP ON INPUT, DATA RATE = 8GT/s INEQ0 = 1, INEQ1 = 0, VIN = 500mVP-P, OEQ0 = OEQ1 = OEQ2 = 0, 12in MICROSTRIP ON INPUT, DATA RATE = 8GT/s MAX14955 toc28 400 VOLTAGE (mV) 400 600 200 0 -200 -400 -600 -800 -100 -50 0 TIME (ps) www.maximintegrated.com 50 100 200 600 400 VOLTAGE (mV) 600 MAX14950A toc29 TIME (ps) 800 VOLTAGE (mV) -200 -600 -600 -50 0 -400 -600 -100 200 0 -200 200 0 -200 -400 -400 -600 -600 -100 -50 0 TIME (ps) 50 100 MAX14950A toc30 VOLTAGE (mV) 400 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, OEQ0 = 0, OEQ1 = 1, OEQ2 = 1, DATA RATE = 8GT/s MAX14955 toc27 MAX14955 toc25 600 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, OEQ0 = 1, OEQ1 = 0, OEQ2 = 1, DATA RATE = 8GT/s MAX14955 toc26 INEQ0 = INEQ1 = 0, VIN = 200mVP-P, OEQ0 = 0, OEQ1 = 0, OEQ2 = 1, DATA RATE = 8GT/s -100 -50 0 50 100 TIME (ps) Maxim Integrated │ 11 MAX14955 Single-Lane PCIe Gen III Redriver with Equalization and Extended Temperature Operation Typical Operating Characteristics (continued) (VCC = +3.3V, TA = +25NC, unless otherwise noted.) 0 -200 200 0 -200 200 100 0 -100 -400 -200 -600 -600 -300 0 50 100 -100 -50 50 250 200 150 0 -100 100 50 0 -100 -150 -100 -200 -250 0 TIME (ps) www.maximintegrated.com 50 100 50 100 300 200 100 0 -100 -200 -200 -300 0 DATA RATE = 8Gbps, OUTPUT AFTER 19in STRIPLINE, INEQ_0 = INEQ_1 = 0, VIN = 200mVP-P VOLTAGE (mV) VOLTAGE (mV) 100 -50 -50 TIME (ps) MAX14955 toc35 200 -100 -100 100 DATA RATE = 8Gbps, OUTPUT AFTER 19in STRIPLINE, INEQ_0 = INEQ_1 = 0, VIN = 200mVP-P DATA RATE = 8Gbps, OUTPUT AFTER 19in STRIPLINE, INEQ_0 = INEQ_1 = 0, VIN = 200mVP-P MAX14955 toc34 300 0 TIME (ps) MAX14595 toc36 -50 TIME (ps) VOLTAGE (mV) 300 -400 -100 MAX14955 toc33 400 VOLTAGE (mV) 200 600 VOLTAGE (mV) 400 DATA RATE = 8Gbps, OUTPUT AFTER 19in STRIPLINE, INEQ_0 = INEQ_1 = 0, VIN = 200mVP-P MAX14950A toc32 600 VOLTAGE (mV) INEQ0 = 1, INEQ1 = 1, VIN = 500mVP-P, OEQ0 = OEQ1 = OEQ2 = 0, 24in MICROSTRIP ON INPUT, DATA RATE = 8GT/s MAX14950A toc31 INEQ0 = 0, INEQ1 = 1, VIN = 500mVP-P, OEQ0 = OEQ1 = OEQ2 = 0, 18in MICROSTRIP ON INPUT, DATA RATE = 8GT/s -300 -100 -50 0 TIME (ps) 50 100 -100 -50 0 50 100 TIME (ps) Maxim Integrated │ 12 MAX14955 Single-Lane PCIe Gen III Redriver with Equalization and Extended Temperature Operation Typical Operating Characteristics (continued) (VCC = +3.3V, TA = +25NC, unless otherwise noted.) MAX14955 toc37 250 200 100 300 200 VOLTAGE (mV) 50 0 -100 -150 -100 0 -100 -200 -200 -300 -250 -100 -50 0 50 100 -100 -50 0 50 100 TIME (ps) TIME (ps) DATA RATE = 8Gbps, OUTPUT AFTER 19in STRIPLINE, INEQ_0 = INEQ_1 = 0, VIN = 200mVP-P DATA RATE = 8Gbps, OUTPUT AFTER 19in STRIPLINE, INEQ_0 = INEQ_1 = 0, VIN = 200mVP-P 500 MAX14955 toc39 250 200 150 100 400 300 VOLTAGE (mV) VOLTAGE (mV) 100 50 0 -100 -150 -100 MAX14955 toc40 VOLTAGE (mV) 150 MAX14955 toc38 DATA RATE = 8Gbps, OUTPUT AFTER 19in STRIPLINE, INEQ_0 = INEQ_1 = 0, VIN = 200mVP-P DATA RATE = 8Gbps, OUTPUT AFTER 19in STRIPLINE, INEQ_0 = INEQ_1 = 0, VIN = 200mVP-P 200 100 0 -100 -200 -300 -200 -400 -250 -500 -100 -50 0 TIME (ps) www.maximintegrated.com 50 100 -100 -50 0 50 100 TIME (ps) Maxim Integrated │ 13 MAX14955 Single-Lane PCIe Gen III Redriver with Equalization and Extended Temperature Operation GND 21 INBP 24 23 22 GND GND RXDET 28 27 26 25 INBM 30 29 OUTAM GND I.C. TOP VIEW OUTAP Pin Configuration GND 31 20 I.C. I.C. 32 19 I.C. VCC 33 18 VCC I.C. 34 17 I.C. OEQA0 35 16 INEQB0 MAX14955 OEQA1 36 15 INEQB1 14 OEQB0 OEQA2 37 INEQA0 38 13 OEQB1 EP* + INEQA1 39 12 OEQB2 11 VCC 4 5 6 7 GND INAP INAM GND EN GND TQFN (5mm x 5mm) 8 9 10 GND 3 OUTBM 2 OUTBP 1 GND VCC 40 *EXPOSED PAD. CONNECT TO GND. Pin Description PIN NAME 1, 2, 5, 7, 10, 21, 24, 26, 29, 31 GND FUNCTION Ground 3 INAP Noninverting Input, Channel A 4 INAM Inverting Input, Channel A 6 EN 8 OUTBP Noninverting Output, Channel B Inverting Output, Channel B Enable Input. Drive EN low for standby mode. Drive EN high for normal mode. EN has a 375kI (typ) internal pulldown resistor. 9 OUTBM 11, 18, 33, 40 VCC Power-Supply Input. Bypass VCC to GND with 0.1FF and 0.01FF capacitors in parallel as close as possible to the device. 12 OEQB2 Output Deemphasis Control MSB, Channel B. OEQB2 has a 375kI (typ) internal pulldown resistor. 13 OEQB1 Output Deemphasis Bit 1, Channel B. OEQB1 has a 375kI (typ) internal pulldown resistor. www.maximintegrated.com Maxim Integrated │ 14 MAX14955 Single-Lane PCIe Gen III Redriver with Equalization and Extended Temperature Operation Pin Description (continued) PIN NAME 14 OEQB0 FUNCTION Output Deemphasis Control LSB, Channel B. OEQB0 has a 375kI (typ) internal pulldown resistor. 15 INEQB1 Input Equalization Control MSB, Channel B. INEQB1 has a 375kI (typ) internal pulldown resistor. 16 INEQB0 Input Equalization Control LSB, Channel B. INEQB0 has a 375kI (typ) internal pulldown resistor. 17, 19, 20, 30, 32, 24 I.C. Internally Connected. Leave I.C. unconnected. 22 INBM Inverting Input, Channel B 23 INBP Noninverting Input, Channel B 25 RXDET Receiver Detection Control Bit. Toggle RXDET to initiate receiver detection. RXDET has a 375kI (typ) internal pulldown resistor. 27 OUTAM Inverting Output, Channel A 28 OUTAP Noninverting Output, Channel A 35 OEQA0 Output Deemphasis Control LSB, Channel A. OEQA0 has a 375kI (typ) internal pulldown resistor. 36 OEQA1 Output Deemphasis Control Bit 1, Channel A. OEQA1 has a 375kI (typ) internal pulldown resistor. 37 OEQA2 Output Deemphasis Control MSB, Channel A. OEQA2 has a 375kI (typ) internal pulldown resistor. 38 INEQA0 Input Equalization Control LSB, Channel A. INEQA0 has a 375kI (typ) internal pulldown resistor. 39 INEQA1 Input Equalization Control MSB, Channel A. INEQA1 has a 375kI (typ) internal pulldown resistor. — EP www.maximintegrated.com Exposed Pad. Internally connected to GND. Connect EP to a large ground plane to maximize thermal performance and ground conductivity to the device. Do not use EP as the only GND connection. Maxim Integrated │ 15 MAX14955 Single-Lane PCIe Gen III Redriver with Equalization and Extended Temperature Operation Functional Diagram EN RXDET OEQ_2 RECEIVER DETECT MANAGER EQUALIZER IN_P IN_M OUT_P EQUALIZER INEQ_0 INEQ_1 OUT_M OUTPUT ENABLE RHI MAX14955 ELECTRICAL IDLE DETECTOR OEQ_0 OEQ_1 Detailed Description The MAX14955 dual equalizer/redriver supports Gen III (8GT/s), Gen II (5GT/s), and Gen I (2.5GT/s) PCIe data rates. The device contains two identical drivers with 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 features 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 for channel A is controlled by two bits: INEQA1 and INEQA0 and for channel B is controlled by two bits: INEQB1 and INEQB0 (Table 1.) Programmable Output Deemphasis Programmable output deemphasis/preshoot for channel A is controlled by the three bits: OEQA2, OEQA1, OEQA0 and channel B is controlled by the three bits: OEQB2, OEQB1, OEQB0 (Table 2.) www.maximintegrated.com 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 part remains in low-power standby mode and the outputs are squelched, despite the logichigh 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 channel is limited to a few retries. Upon receiver detection, input common-mode termination and electrical idle detection are enabled (Table 3.) Table 1. Input Equalization INEQ_1 INEQ_0 INPUT EQUALIZATION (dB) 0 0 5 0 1 8 1 0 12 1 1 16 Maxim Integrated │ 16 MAX14955 Single-Lane PCIe Gen III Redriver with Equalization and Extended Temperature Operation Table 2. Output Deemphasis/Preshoot OEQ_2 OEQ_1 OEQ_0 OUTPUT DEEMPHASIS RATIO (dB) PEAK-TO-PEAK SWING PRESHOOT 0 0 0 0 1.0V No 0 0 1 3.5 1.0V No 0 1 0 6 1.0V No 0 1 1 6 1.2V No 1 0 0 3.5 1.0V Yes 1 0 1 6 1.0V Yes 1 1 0 9 0.9V Yes 1 1 1 9 1.0V Yes 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 a receiver is detected for at least one channel. Retries stop a few times after any channel is detected. Rising/falling edge 1 Initiate receiver detection. X = Don’t care. Electrical Idle Detection The device features electrical idle detection to prevent unwanted noise from being redriven at the output. When the device detects the differential input has fallen below the electrical idle low threshold, it squelches the output. For differential input signals that are above the electrical idle high threshold, the device turns on the output and redrives the signal. Applications Information 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 capacitors must be placed as close as possible to VCC. Always connect VCC to a power plane. It is recommended to run receive and transmit on different layers to minimize crosstalk. www.maximintegrated.com Exposed-Pad Package The exposed-pad, 40-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 plane for proper thermal performance. For more information on exposed-pad packages, refer to Maxim Application Note HFAN-08.1: Thermal Considerations of QFN and Other Exposed-Paddle Packages. Power-Supply Sequencing Caution: Do not exceed the absolute maximum ratings because stresses beyond the listed ratings can 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. Maxim Integrated │ 17 MAX14955 Single-Lane PCIe Gen III Redriver with Equalization and Extended Temperature Operation Ordering Information PART MAX14955ETL+ Package Information TEMP RANGE PIN-PACKAGE -40°C to +85°C 40 TQFN-EP* +Denotes a lead(Pb)-free/RoHS-compliant package. *EP = Exposed pad. Chip Information PROCESS: BiCMOS www.maximintegrated.com 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. 40 TQFN-EP T4055+2 21-0140 90-0002 Maxim Integrated │ 18 MAX14955 Single-Lane PCIe Gen III Redriver with Equalization and Extended Temperature Operation Revision History REVISION NUMBER REVISION DATE 0 3/13 DESCRIPTION Initial release PAGES CHANGED — For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com. 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. 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