19-3297; Rev 1; 10/07 KIT ATION EVALU E L B AVAILA 155Mbps to 3.2Gbps, Low-Power SFP Limiting Amplifiers Features The MAX3747/MAX3747A/MAX3747B multirate limiting amplifiers function as data quantizers for OC-3 through OC-48 synchronous optical network (SONET), FibreChannel, and Gigabit Ethernet optical receivers. They are pin-for-pin compatible with the SY88993V from Micrel Semiconductor, Inc. The amplifiers accept a wide range of input voltages and provide constant-level, current-mode logic (CML) output voltages with controlled edge speeds. The MAX3747 output voltage level is 500mVP-P and the MAX3747A/MAX3747B output voltages are 800mVP-P. The MAX3747B has enhanced LOS operation under overload conditions. The MAX3747/MAX3747A/MAX3747B limiting amplifiers feature a programmable loss-of-signal detect (LOS) and an optional disable function (DISABLE) that can be combined to implement squelch. ♦ Pin Compatible with Micrel SY88993V ♦ 155Mbps to 3.2Gbps Operation ♦ > 57dB of Gain ♦ < 10-12 BER with 2mVP-P Input Amplitude ♦ 18mA Supply Current ♦ Chatter-Free LOS with Programmable Threshold ♦ Output DISABLE Function ♦ PECL-Compatible Inputs Ordering Information TEMP RANGE PINPACKAGE PKG CODE MAX3747EUB -40°C to +85°C 10 µMAX U10C-4 MAX3747AEUB -40°C to +85°C 10 µMAX U10C-4 MAX3747BEUB -40°C to +85°C 10 µMAX U10C-4 PART The MAX3747/MAX3747A/MAX3747B are available in a 3mm, 10-pin µMAX® package ideal for small formfactor receivers. Applications Gigabit Ethernet SFP/SFF Optical Transceiver Modules 1G/2G Fibre-Channel SFP/SFF Optical Transceiver Modules Multirate OC-3 to OC-48 FEC SFP/SFF Optical Transceiver Modules 10G LX4 Transceiver Modules µMAX is a registered trademark of Maxim Integrated Products, Inc. Pin Configuration appears at end of data sheet. Typical Application Circuit SFP OPTICAL RECEIVER 3-INPUT DIAGNOSTIC MONITOR VCC DS1859 MAX4004 HOST BOARD SUPPLY FILTER HOST FILTER VCC_RX VCC 0.1μF MAX3745 IN+ 0.1μF MAX3747 MAX3747A MAX3747B OUT+ IN- OUT- 0.1μF 50Ω SERDES 0.1μF 50Ω 5-PIN TO-HEADER 50Ω VREF 50Ω TH GND LOS DISABLE 4.7kΩ TO 10kΩ VCC_HOST LOS RTH1 0.1μF 0.1μF RTH2 VCC RTH1 + RTH2 ≥ 5kΩ ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX3747/MAX3747A/MAX3747B General Description MAX3747/MAX3747A/MAX3747B 155Mbps to 3.2Gbps, Low-Power SFP Limiting Amplifiers ABSOLUTE MAXIMUM RATINGS Power-Supply Voltage (VCC) .................................-0.5V to +4.5V Voltage at IN+, IN- ..........................(VCC - 2.4V) to (VCC + 0.5V) Voltage at DISABLE, LOS, TH, VREF ..........-0.5V to (VCC + 0.5V) Current into LOS ...................................................-1mA to +9mA Current into VREF ..................................................................2mA Differential Input Voltage (IN+ - IN-) .....................................2.5V Continuous Current at CML Outputs (OUT+, OUT-) ..............................................-25mA to +25mA Continuous Power Dissipation (TA = +70°C) 10-Pin µMAX (derate 6.9mW/°C above +70°C) ...........552mW Operating Junction Temperature Range (TJ) .......-55°C to +150°C Storage Ambient Temperature Range (TS)...........-55°C to +150°C 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 = +2.97V to +3.63V, CML output load is 50Ω to VCC, TA = -40°C to +85°C. Typical values are at VCC = +3.3V and TA = +25°C, unless otherwise specified.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS POWER SUPPLY Supply Current (Note 2) Power-Supply Noise Rejection ICC PSNR MAX3747 including the CML output current 30 35 MAX3747A including the CML output current 36 41 MAX3747B including the CML output current 38 43 MAX3747/MAX3747A excluding the CML output current 18 24 MAX3747B excluding the CML output current 20 26 f < 2MHz 30 mA dB INPUT SPECIFICATION Input Sensitivity VIN-MIN (Note 3) Input Overload VIN-MAX (Note 3) 4 1200 mVP-P mVP-P OUTPUT SPECIFICATION Output Resistance R OUT 42 50 58 Differential Output Return Loss DUT is powered on, f < 3GHz CML Differential Output Voltage MAX3747A/MAX3747B 4mVP-P VIN 1200mVP-P 600 800 1000 MAX3747 4mVP-P VIN 1200mVP-P 400 500 600 Differential Output Signal When Disabled AC-coupled outputs, VIN-MAX applied to the input (Note 4) Data-Output Transition Time 20% to 80% (Note 4) 15 dB mVP-P 15 mVP-P 70 120 ps 13.2 19 14 25 K28.5 pattern at 2.1Gbps 12 17 PRBS 223 - 1 equivalent pattern at 155Mbps (Note 6) 85 150 VIN = 4mVP-P (Notes 4, 7) 3.5 5 TRANSFER CHARACTERISTIC K28.5 pattern at 3.2Gbps PRBS 223 - 1 equivalent pattern at 2.7Gbps Deterministic Jitter (Notes 4, 5) Random Jitter 2 DJ (Note 6) _______________________________________________________________________________________ psP-P psRMS 155Mbps to 3.2Gbps, Low-Power SFP Limiting Amplifiers (VCC = +2.97V to +3.63V, CML output load is 50Ω to VCC, TA = -40°C to +85°C. Typical values are at VCC = +3.3V and TA = +25°C, unless otherwise specified.) (Note 1) PARAMETER SYMBOL Input-Referred Noise CONDITIONS MIN VIN = 4mVP-P (Note 4) Low-Frequency Cutoff TYP MAX UNITS 120 150 μVRMS 6.4 LOS Hysteresis 10log(VDEASSERT / VASSERT) (Note 4) MAX3747/MAX3747A (Notes 4, 8) LOS Assert/Deassert Time MAX3747B (Notes 4, 8, 9) Low LOS Assert Level VTH = -1.3V (Notes 4, 10) Low LOS Deassert Level VTH = -1.3V (Notes 4, 10) Medium LOS Assert Level VTH = -0.68V (Notes 4, 10) Medium LOS Deassert Level VTH = -0.68V (Notes 4, 10) High LOS Assert Level VTH = -0.114V (Notes 4, 10) High LOS Deassert Level VTH = -0.114V (Notes 4, 10) kHz 1.25 dB 2.3 40.0 μs 5.9 mVP-P 2.5 4.1 6.2 9.3 mVP-P 22.0 29.0 31.0 mVP-P 44.8 57.0 mVP-P 53.7 63.6 mVP-P 86.0 115 mVP-P VCC 1.3V VCC 1.19 V 36.0 TTL/CMOS I/O VCC 1.35 VREF Voltage VREF LOS Output High Voltage VOH RLOS = 4.7k to 10k to VCC_HOST (3V) LOS Output Low Voltage VOL RLOS = 4.7k to 10k to VCC_HOST (3.6V) DISABLE Input High VIH DISABLE Input Low VIL DISABLE Input Current 2.4 V 0.4 2.0 RLOS = 4.7k to 10k to VCC_HOST V V 0.8 V 10 μA The data-input transition time is controlled by a 4th-order Bessel filter with f-3dB = 0.75 x 2.667GHz for all data rates of 2.667Gbps and below. The f-3db = 0.75 x 3.2GHz for a data rate of 3.2Gbps. Note 2: Supply current is measured with unterminated outputs or with AC-coupled output termination (see Figure 1). Note 3: Between sensitivity and overload, all AC specifications are met and the output is 0.95 x limited output amplitude. Note 4: Guaranteed by design and characterization. Note 5: The deterministic jitter (DJ) caused by the input filter is not included in the DJ generation specification. Note 6: The PRBS 223 - 1 equivalent pattern consists of a K28.5 pattern plus 240 ones plus K28.5 pattern plus 240 zeros. Note 7: Random jitter was measured without using a filter at the input. Note 8: The signal at the input is switched between two amplitudes, Signal_ON and Signal_OFF, as shown in Figure 2A. Note 9: The signal at the input is switched between 1.2VP-P and Signal_OFF as shown in Figure 2B. Note 10: VTH is the voltage at pin 5 referenced to VCC (see Figure 5). Note 1: _______________________________________________________________________________________ 3 MAX3747/MAX3747A/MAX3747B ELECTRICAL CHARACTERISTICS (continued) MAX3747/MAX3747A/MAX3747B 155Mbps to 3.2Gbps, Low-Power SFP Limiting Amplifiers VCC ICC (SUPPLY CURRENT) IOUT (CML OUTPUT CURRENT) 50Ω 50Ω MAX3747 MAX3747A MAX3747B Figure 1. Power-Supply Current Measurement VIN VIN SIGNAL_ON = 1.2VP-P (OVERLOAD) SIGNAL_ON 1dB MAXIMUM DEASSERT LEVEL FOR A GIVEN VTH 6dB MAXIMUM POWER-DETECT WINDOW MAXIMUM DEASSERT LEVEL FOR A GIVEN RTH1/RTH2 RATIO 6dB MINIMUM ASSERT LEVEL FOR A GIVEN RTH1/RTH2 RATIO MINIMUM ASSERT LEVEL FOR A GIVEN VTH 0V SIGNAL_OFF TIME Figure 2A. LOS Deassert Threshold—Set 1dB Below Receiver Sensitivity 4 MAXIMUM POWER-DETECT WINDOW 0V SIGNAL_OFF Figure 2B. LOS Deassert Threshold—Operating at Input Overload _______________________________________________________________________________________ TIME 155Mbps to 3.2Gbps, Low-Power SFP Limiting Amplifiers OUTPUT EYE DIAGRAM (MINIMUM INPUT) OUTPUT EYE DIAGRAM (MINIMUM INPUT) OUTPUT EYE DIAGRAM (MAXIMUM INPUT) MAX3747/MAX3747A/MAX3747B toc01 MAX3747/MAX3747A/MAX3747B toc03 MAX3747/MAX3747A/MAX3747B toc02 3.2Gbps, 223 - 1 PRBS, 4mVP-P 2.7Gbps, 223 - 1 PRBS, 4mVP-P 3.2Gbps, 223 - 1 PRBS, 1200mVP-P 60mV/div 60mV/div 60mV/div 50ps/div 70ps/div 50ps/div OUTPUT EYE DIAGRAM (MAXIMUM INPUT) SUPPLY CURRENT vs. TEMPERATURE (EXCLUDES OUTPUT CURRENT) OUTPUT EYE DIAGRAM AT +100°C MAX3747/MAX3747A/MAX3747B toc05 2.7Gbps, 223 - 1 PRBS, 1200mVP-P 50 2.125Gbps, CJTPAT, 50mVP-P MAX3747/MAX3747A/MAX3747B toc06 MAX3747/MAX3747A/MAX3747B toc04 SUPPLY CURRENT (mA) 45 60mV/div 60mV/div 40 35 30 25 20 15 10 80ps/div TRANSFER FUNCTION (OUTPUT VOLTAGE vs. INPUT VOLTAGE) 600 500 MAX3747 400 300 2.4 2.1 1.8 1.5 1.2 0.9 200 0.6 100 0.3 0 1 2 3 4 DIFFERENTIAL INPUT (mVP-P) 5 3.2Gbps 4 3 2 1 0 0 RANDOM JITTER vs. INPUT AMPLITUDE 5 RANDOM JITTER (psRMS) MAX3747AMAX3747B 2.7 VIN = 50mVP-P, FREQ = 2.7Gbps MAX3747/MAX3747A/MAX3747B toc08 800 3.0 RANDOM JITTER (psRMS) DIFFERENTIAL OUTPUT (mVP-P) 900 700 RANDOM JITTER vs. TEMPERATURE MAX3747/MAX3747A/MAX3747B toc07 1000 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 TEMPERATURE (°C) MAX3747/MAX3747A/MAX3747B toc09 70ps/div 0 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 TEMPERATURE (°C) 1 10 100 1000 10,000 DIFFERENTIAL INPUT AMPLITUDE (mVP-P) _______________________________________________________________________________________ 5 MAX3747/MAX3747A/MAX3747B Typical Operating Characteristics (VCC = +3.3V, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VCC = +3.3V, TA = +25°C, unless otherwise noted.) DETERMINISTIC JITTER vs. INPUT AMPLITUDE 3 4 5 6 7 8 9 10 1 10 100 1000 MAX3747/MAX3747A/MAX3747B toc12 20 15 VIN = 5mVP-P 10 10,000 DIFFERENTIAL INPUT AMPLITUDE (mVP-P) LOS ASSERT/DEASSERT TIMES vs. INPUT AMPLITUDE (LOW RTH1/RTH2 SETTINGS) LOS ASSERT/DEASSERT TIMES vs. INPUT AMPLITUDE (HIGH RTH1/RTH2 SETTINGS) 25 LOS ASSERT 20 15 LOS DEASSERT 10 MAX3747/MAX3747A/MAX3747B toc14 30 40 MAX3747B LOS ASSERT/DEASSERT TIME (μs) MAX3747/MAX3747A/MAX3747B toc13 35 30 25 20 LOS DEASSERT 15 LOS ASSERT 10 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 TEMPERATURE (°C) ASSERT/DEASSERT vs. VTH 120 110 5 0 0 0 200 400 600 800 1000 1200 1400 100 90 VTH (V) = VOLTAGE AT PIN 5 (V) WITH RESPECT TO VCC 80 70 60 50 40 DEASSERT ASSERT 30 20 10 0 0 200 400 600 800 1000 1200 1400 -1.4 -1.2 -1.0 -0.8 -0.6 -0.4 -0.2 0 INPUT AMPLITUDE (mVP-P) VTH (V) ASSERT/DEASSERT vs. TEMPERATURE OUTPUT RETURN vs. FREQUENCY (SDD22) (INPUT SIGNAL LEVEL = -60dBm) INPUT RETURN vs. FREQUENCY (SDD11) (INPUT SIGNAL LEVEL = -60dBm) DEASSERT 15 ASSERT 5 10 0 20 10 0 -10 -10 -20 -20 -30 -30 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 TEMPERATURE (°C) MAX3747/MAX3747A/MAX3747B toc18 25 20 30 SDD11 (dB) 30 30 SDD22 (dB) VTH = -1.1V, FREQ = 2.7Gbps PATTERN = PRBS 223 - 1 MAX3747/MAX3747A/MAX3747B toc16 INPUT AMPLITUDE (mVP-P) MAX3747/MAX3747A/MAX3747B toc17 LOS ASSERT/DEASSERT TIME (μs) 25 MAX3747/MAX3747A/MAX3747B toc15 2 ASSERT/DEASSERT (mVP-P) 1 5 6 30 0 DIFFERENTIAL INPUT AMPLITUDE (mVP-P) MAX3747B 10 5 FREQ = 3.2Gbps PATTERN = K28.5 VIN = 500mVP-P 35 20 10 0 40 35 15 35 5 0 40 20 40 DETERMINISTIC JITTER (ps) MICREL SY88993V 3.2Gbps, K28.5 PATTERN MAX3747/MAX3747A/MAX3747B toc11 MAXIM MAX3747 DETERMINISTIC JITTER vs. TEMPERATURE 25 DETERMINISTIC JITTER (psP-P) 13,000 12,000 11,000 10,000 9000 8000 7000 6000 5000 4000 3000 2000 1000 1 MAX3747/MAX3747A/MAX3747B toc10 BIT-ERROR RATIO (10-12) BIT-ERROR RATIO vs. INPUT VOLTAGE ASSERT/DEASSERT (mV) MAX3747/MAX3747A/MAX3747B 155Mbps to 3.2Gbps, Low-Power SFP Limiting Amplifiers 100 1000 FREQUENCY (MHz) 10,000 100 1000 FREQUENCY (MHz) _______________________________________________________________________________________ 10,000 155Mbps to 3.2Gbps, Low-Power SFP Limiting Amplifiers PIN MAX3747/ MAX3747A/ MAX3747B MICREL SY8893V NAME NAME FUNCTION 1 DISABLE EN Disable Function Pin. The data outputs are held static when this pin is asserted high, transistor-to-transistor logic (TTL). The data outputs are enabled when this pin is held low. LOS functions remain active when outputs are disabled. For normal operation connect to GND. 2 IN+ DIN Noninverted Input Signal 3 IN- DIN Inverted Input Signal 4 VREF VREF Reference Voltage for LOS Threshold Setting Loss-of-Signal Level Set. A voltage on this pin created by a two-resistor divider sets the threshold level. Connect one resistor from this pin to VCC and another from this pin to VREF (see Figure 5). 5 TH LOSLVL 6 GND GND Ground Loss of Signal. Open collector for the MAX3747 and MAX3747A; internal 100k pullup to VCC for the MAX3747B. LOS is high when the level of the input signal drops below the preset threshold set by the TH input. LOS is deasserted low when the signal level is above the threshold. 7 LOS LOS 8 OUT- DOUT 9 OUT+ DOUT 10 VCC VCC Inverted Data Output, CML Noninverted Data Output, CML Positive Power Supply Detailed Description The limiting amplifiers consist of a multistage amplifier, offset-correction circuitry, an output buffer, and loss-ofsignal detect circuitry (see the Functional Diagram). VCC MAX3747 MAX3747A MAX3747B Input Stage The input stage is shown in Figure 3. It provides 50Ω termination to VREF for each input signal, IN+ and IN-. The MAX3747/MAX3747A/MAX3747B should be AC-coupled. Multistage Amplifier ESD STRUCTURES The high-bandwidth multistage amplifier provides approximately 57dB of gain for the MAX3747 and 61dB of gain for the MAX3747A/MAX3747B. Offset Correction Loop The MAX3747/MAX3747A/MAX3747B are susceptible to DC offsets in the signal path because they have high gain. In communication systems using NRZ data with a 50% duty cycle, pulse-width distortion present in the signal or generated in the transimpedance amplifier appears as an input offset and is reduced by the offset correction loop. The offset correction loop sets a low-frequency cutoff of 3.2kHz. 50Ω 50Ω VREF Figure 3. Differential Input Stage _______________________________________________________________________________________ 7 MAX3747/MAX3747A/MAX3747B Pin Description 155Mbps to 3.2Gbps, Low-Power SFP Limiting Amplifiers MAX3747/MAX3747A/MAX3747B Functional Diagram VCC MAX3747 MAX3747A MAX3747B DIGITAL OFFSET CORRECTION 50Ω 50Ω OUT+ OUT- IN+ IN- 50Ω DISABLE 50Ω VREF VREF SIGNAL DETECT VREF TH LOS RTH1 RTH2 RTH1 + RTH2 ≥ 5kΩ VCC CML Output Buffer The CML outputs of the MAX3747/MAX3747A/ MAX3747B limiting amplifiers provide high tolerance to impedance mismatches and inductive connectors. The output current is approximately 10mA for the MAX3747 and 16mA for the MAX3747A/MAX3747B. Connecting the DISABLE pin to VCC disables the output. If the LOS pin is connected to the DISABLE pin, the outputs OUT+ and OUT- are at a static voltage (squelch) whenever the input signal level drops below the LOS threshold. The output buffer can be AC- or DC-coupled to the load (Figure 4). The MAX3747 output is 500mVP-P and the MAX3747A/ MAX3747B output is 800mVP-P. VCC 50Ω 50Ω OUT+ OUTDISABLE Q3 Q4 Q1 Q2 ESD STRUCTURES DATA DISABLE DISABLE Figure 4. CML Output Buffer 8 _______________________________________________________________________________________ 155Mbps to 3.2Gbps, Low-Power SFP Limiting Amplifiers VCC Applications Information Program the LOS Assert Threshold Program the LOS assert threshold according to Figure 5. The combination of R TH1 and R TH2 should be greater than or equal to 5kΩ, see the Assert/Deassert vs. VTH graph in the Typical Operating Characteristics. Select the Coupling Capacitor When AC-coupling is desired, coupling capacitors CIN and COUT should be selected to minimize the receiver’s deterministic jitter. Jitter is decreased as the input low-frequency cutoff (fIN) is decreased: fIN = 1 / [2π(50)(CIN)] For all applications, the recommended value for CIN and COUT is 0.1µF, which provides fIN equal to 32kHz. Refer to Application Note HFAN-1.1: Choosing AC-Coupling Capacitors on the Maxim website (www.maxim-ic.com). RTH2 TH RTH1 VREF VTH = (RTH2 x (VREF - VCC)) / (RTH1 + RTH2) VTH IS VCC REFERENCED RTH1 + RTH2 ≥ 5kΩ Figure 5. MAX3747/MAX3747A/MAX3747B LOS Threshold Circuit VCC * LOS ESD STRUCTURE *100kΩ PULLUP (MAX3747B ONLY) Figure 6. MAX3747/MAX3747A/MAX3747B LOS Output Circuit _______________________________________________________________________________________ 9 MAX3747/MAX3747A/MAX3747B Loss-of-Signal Indicator The MAX3747/MAX3747A/MAX3747B are equipped with LOS circuitry that indicates when the input signal is below a programmable threshold, set by a voltage on the TH pin (see the Typical Operating Characteristics). The voltage on the TH pin is set by two resistors, one connecting from the TH pin to VCC and the other connecting from TH to VREF (Figure 5). An RMS power detector compares the input signal amplitude with this threshold and feeds the signal-detect information to the LOS output, which is open collector. To prevent LOS chatter in the region of the programmed threshold, approximately 2dB of hysteresis is built into the LOS assert/deassert function. Once asserted, LOS is not deasserted until the input amplitude rises to the required level. Figure 6 shows the LOS output circuit. MAX3747/MAX3747A/MAX3747B 155Mbps to 3.2Gbps, Low-Power SFP Limiting Amplifiers Pin Configuration Chip Information TRANSISTOR COUNT: 447 PROCESS: SiGe Bipolar TOP VIEW Package Information For the latest package outline information, go to www.maxim-ic.com/packages. PACKAGE TYPE DOCUMENT NO. 10 µMAX 21-0061 DISABLE 1 IN+ 10 VCC 2 IN- 3 VREF 4 TH 5 MAX3747 MAX3747A MAX3747B 9 OUT+ 8 OUT- 7 LOS 6 GND μMAX Revision History Pages changed at Rev 1: 1 to 10 (added MAX3747B) 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 © 2007 Maxim Integrated Products SPRINGER is a registered trademark of Maxim Integrated Products.