SY88063AL 3.3V, 12.5Gbps Limiting Post Amplifier with Automatic Digital Offset Correction General Description Features The SY88063AL is a multi-rate limiting post amplifier designed for fiber-optic transceivers applications up to 12.5Gbps. It features an automatic digital offset correction function. The offset correction feature will automatically counteract any inherent offset present in the input signal and amplifier. The highly sensitive SY88063AL can amplify input signals as low as 20mVpp at 12.5Gbps or 10mVpp at 10.3Gbps to differential CML output levels. The SY88063AL generates a loss-of-signal (LOS) opencollector TTL output. A programmable loss-of-signal level set pin (LOSLVL) sets the sensitivity of the input amplitude detection. LOS asserts high if the input amplitude falls below the threshold set by LOSLVL and de-asserts low otherwise. The enable input (/EN) de-asserts the true output signal without removing the input signal. The LOS output can be fed back to the /EN input to implement the squelch function that maintains output stability under a loss-of-signal condition. The SY88063AL operates from a single +3.3V power o o supply, over –40 C to +85 C, and is available in 3mm x 3mm 16-pin QFN package. All support documentation can be found on Micrel’s web site at: www.micrel.com. • • • • • • • • Up to 12.5Gbps operation Automatic Digital Offset Correction Programmable LOS level (LOSLVL) Squelching function to maintain output stability Low-noise CML data outputs TTL /EN input –40oC to +85oC Operation Small 3mm x 3mm QFN package Applications • • • • 1x/2x/4x/8x Fibre Channel SR/LR SFP+ Optical Transceiver 10GPON ONU SONET/SDH:OC192 – STM64 Markets • Datacom/telecom • Optical transceiver ________________________________________________________________________________________________ Typical Application Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com September 2011 M9999-090911-B [email protected] or (408) 955-1690 Micrel, Inc. SY88063AL Ordering Information Package Type Operating Range Package Marking SY88063ALMG Part Number Lead-Free QFN-16 Industrial 063A with Pb-Free Bar Line Indicator SY88063ALMG TR(1) Lead-Free QFN-16 Industrial 063A with Pb-Free Bar Line Indicator Note: 1. Tape and Reel. Pin Configuration 3mm x 3mm QFN-16 Pin Description Pin Number Pin Name Type Pin Function Differential data inputs. Each input is internally terminated to approximately VCC – 1.3V by a 50Ω resistor. AC-Couple input signals. 2, 3 DIN, /DIN Data Input 5, 6, 14, 16 NC No Connection 7 LOS Open-Collector TTL Output Loss-of-Signal: Asserts HIGH when the data input amplitude falls below the threshold set by LOSLVL. 8 LOSLVL DC Input Loss-of-Signal Level Set. A resistor from this pin to VCC sets the threshold for the data input amplitude at which LOS will be asserted. 10, 11 /DOUT, DOUT CML Output September 2011 Unused Pins. Leave open. Differential Data Outputs. Unused output should be terminated 50Ω-to-VCC. 2 M9999-090911-B [email protected] or (408) 955-1690 Micrel, Inc. SY88063AL Pin Description (Continued) Pin Number Pin Name Type Pin Function 13 LOCKED LVTTL Output Once digital offset correction is locked based input signal, this pin will output a LVTTL HIGH. 15 /EN LVTTL Input /Enable: This input enables the outputs when it is LOW. Note that this input is internally connected to a 25kΩ pull-up resistor and will default to a logic HIGH state if left open. 1, 4 GND Ground 9, 12 VCC Power Supply September 2011 Device Ground. Exposed pad must be soldered (or equivalent) to the same potential as the ground pins. Positive Power Supply. Bypass with 0.1μF | | 0.01μF low ESR capacitors. 0.01μF capacitors should be as close as possible to VCC pins. 3 M9999-090911-B [email protected] or (408) 955-1690 Micrel, Inc. SY88063AL Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VCC) ....................................... 0V to +4.0V Input Voltage (DIN, /DIN) .......................................0 to VCC Output Current (IOUT) ............................................... ±25mA EN Voltage .............................................................0 to VCC LOSLVL Voltage.......................................... VCC-1.3V to VCC Lead Temperature (soldering, 20sec.) ..................... 260°C Storage Temperature (Ts) ....................... –65°C to +150°C Supply Voltage (VCC)............................ +3.0V to +3.6V Ambient Temperature (TA).................. –40°C to +85°C Package Thermal Resistance(3) QFN (θJA) Still-air ...............................................60°C/W (ψJB) ...........................................................33°C/W DC Electrical Characteristics VCC = 3.0 to 3.6V; TA = –40°C to +85°C, typical values at VCC = 3.3V, TA = 25°C. Symbol Parameter Condition Min. Typ. Max. Units ICC Power Supply Current With 50Ω Output Load 53 72 mA LOSLVL LOSLVL Voltage VCC V VOH DOUT, /DOUT HIGH Voltage VCC − 0.020 VCC − 0.005 VCC V VOL DOUT, /DOUT LOW Voltage VCC − 0.400 VCC − 0.350 VCC −0.300 V Z0 Single-Ended Output Impedance 45 50 55 Ω ZI Single-Ended Input Impedance 45 50 55 Ω Min. Typ. Max. Units VCC −1.3 TTL DC Electrical Characteristics VCC = 3.0 to 3.6V; TA = –40°C to +85°C, typical values at VCC = 3.3V, TA = 25°C. Symbol Parameter Condition VIH /EN Input HIGH Voltage VIL /EN Input LOW Voltage IIH /EN Input HIGH Current IIL /EN Input LOW Current VIN = 0.5V −0.3 mA VOH LOS Output HIGH Level Sourcing 100µA 2.4 V VOL LOS Output LOW Level Sinking 2mA 2.0 V 0.8 VIN = 2.7V 20 VIN = VCC 100 0.5 V µA V Notes: 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 ratings conditions for extended periods may affect device reliability. 2. The data sheet limits are not guaranteed if the device is operated beyond the operating ratings. 3. Package Thermal Resistance assumes exposed pad is soldered (or equivalent) to the devices most negative potential on the PCB. ψJB uses a 4-layer and θJA in still air unless otherwise stated. September 2011 4 M9999-090911-B [email protected] or (408) 955-1690 Micrel, Inc. SY88063AL AC Electrical Characteristics VCC = 3.0 to 3.6V; RLoad = 50Ω to VCC; TA = –40°C to +85°C, typical values at VCC = 3.3V, TA = 25°C. Symbol FIN tr, tf tJITTER Parameter Condition Min. Input Data Rate NRZ Data 1.25 Output Rise/Fall Time Typ. Max. Units 12.5 Gbps 35 ps Note 4 25 Deterministic Note 5 10 psPP Random Note 6 1 psRMS (20% to 80%) VID Differential Input Voltage Swing VOD Differential Output Voltage Swing FIN = 12.5Gbps 20 FIN = 10.3Gbps 10 Note 4 600 700 1800 mVPP 800 mVPP TOFF LOS Release Time Note 9 100 500 ns TON LOS Assert Time Note 9 100 500 ns LOSAL Low LOS Assert Level RLOSLVL = 10kΩ, Note 7 9 11 13 mVPP LOSDL Low LOS De-Assert Level RLOSLVL = 10kΩ, Note 7 14 16 19 mVPP HSYL Low LOS Hysteresis RLOSLVL = 10kΩ, Note 8 2 3.5 4 dB LOSAM Medium LOS Assert Level RLOSLVL = 5kΩ, Note 7 16 18 21 mVPP LOSDM Medium LOS De-Assert Level RLOSLVL = 5kΩ, Note 7 23 26 29 mVPP HSYM Medium LOS Hysteresis RLOSLVL = 5kΩ, Note 8 2 3 4 dB LOSAH High LOS Assert Level RLOSLVL = 100Ω, Note 7 40 46 54 mVPP LOSDH High LOS De-Assert Level RLOSLVL = 100Ω, Note 7 61 68 74 mVPP HSYH High LOS Hysteresis RLOSLVL = 100Ω, Note 8 2 3 4 B-3dB 3dB Bandwidth 10 GHz AV(Diff) Differential Voltage Gain 38 dB S21 Single-Ended Small-Signal Gain 32 dB 26 dB Notes: 4. Amplifier in limiting mode. Input is a 200MHz square wave. 5. Deterministic jitter measured using 10 Gbps K28.5 pattern, VID = 60mVPP. 6. Random jitter measured using 10Gbps K28.7 pattern, VID = 60mVPP. 7. See “Typical Operating Characteristics” for a graph showing how to choose a particular RLOSLVL for a particular LOS assert and its associated de-assert amplitude. 8. This specification defines electrical hysteresis as 20log (LOS De-Assert/LOS Assert). The ratio between optical hysteresis and electrical hysteresis is found to vary between 1.5 and 2 depending upon the level of received optical power and ROSA characteristics. Based on that ratio, the optical hysteresis corresponding to the electrical hysteresis range 1dB-4.5 dB, shown in the AC characteristics table, will be 0.5dB3dB Optical Hysteresis. 9. In real world applications, the LOS Release/Assert time can be strongly influenced by the RC time constant of the AC-coupling cap and the 50Ω input termination. To keep this time low, use a decoupling cap with the lowest value that is allowed by the data rate and the number of consecutive identical bits in the application (typical values are in the range of 0.001µF to 1.0µF). September 2011 5 M9999-090911-B [email protected] or (408) 955-1690 Micrel, Inc. SY88063AL Typical Operating Characteristics VCC = 3.3V, TA = 25°C, RL = 50Ω to VCC-2V, unless otherwise stated. LOS Assert/De-Assert Levels LOS Hysteresis 6 5 Hysteresis (dB) Signal Amplitude (mV) 100 10 4 3 2 1 1 0.1 1 10 0.1 100 1 10 100 LOSLVL Resistor (KΩ) LOSLVL Resistor (KΩ) Typical Functional Characteristics VCC = 3.3V, TA = 25°C, RL = 50Ω to VCC-2V, unless otherwise stated. September 2011 6 M9999-090911-B [email protected] or (408) 955-1690 Micrel, Inc. SY88063AL Functional Block Diagram September 2011 7 M9999-090911-B [email protected] or (408) 955-1690 Micrel, Inc. SY88063AL Detailed Description LOS-Level Set A programmable LOS level set pin (LOSLVL) sets the threshold of the input amplitude detection. Connecting an external resistor between VCC and LOSLVL sets the voltage at LOSLVL. This voltage ranges from VCC to VCC-1.3V. The external resistor creates a voltage divider between VCC and VCC-1.3V, as shown in Figure 5. The SY88063AL is a high-sensitivity limiting post amplifier that operates from a single +3.3V power supply over temperatures from –40°C to +85°C. The SY88063AL can process input signals up to 12.5Gbps and as small as 20mVpp. It can also process signals as small as 10mVpp with data rates as high as 10.7Gbps. Figure 1 shows the acceptable input ranges. The SY88063AL generates a LOS output signal that can be fed back to /EN for output stability in the absence of a signal at the input. LOSLVL sets the sensitivity of the input amplitude detection. By adjusting the voltage at the LOSLVL pin, either through an external voltage source or a resistor, the SY88063AL can trigger LOS on signals from 10mVpp to 70mVpp. Hysteresis The SY88063AL provides typically 3dB LOS electrical hysteresis, which is defined as 20log (VINLOS-Assert / VINLOS-De-Assert). Since the relationship between the voltage out of the ROSA to optical power at its input is linear, the optical hysteresis will be typically half of the electrical hysteresis reported in the datasheet, but in practice the ratio between electrical and optical hysteresis is found to be within the range 1.5-1.8. Input Amplifier/Buffer Figure 2 shows a simplified schematic of the input stage. The high-sensitivity of the input amplifier allows signals as small as 10mVpp to be detected and amplified. The input amplifier allows input signals as large as 1800mVpp. Input signals are amplified with a typically 38dB differential voltage gain. Since it is a limiting amplifier, the SY88063AL outputs typically 700mVpp voltage-limited waveforms for input signals that are greater than 7mVpp. Digital Offset Correction The SY88063AL features automatic digital offset correction function. The conventional analog offset correction is susceptible to offset drift from long input patterns of exclusively 0s or 1s. The SY88063AL is not limited by the input patterns. This feature will automatically detect any existing offset and lock the offset correction. The offset correction will not be applied to large input signals that place the outputs into limiting mode. Output Buffer The SY88063AL’s CML output buffer is designed to drive 50Ω lines and is internally terminated with 50Ω to VCC. Figure 3 shows a schematic of the output stage. Loss-of-Signal (LOS) The SY88063AL generates a chatter-free loss-of-signal (LOS) open-collector TTL output as shown in Figure 4. LOS is used to determine if the input amplitude is too small to be considered as a valid input. LOS asserts high if the input amplitude falls below the threshold set by LOSLVL and de-asserts low otherwise. LOS can be fed back to the enable (/EN) input to maintain output stability under a loss of signal condition. /EN de-asserts low the true output signal without removing the input signals. Typically, 3dB LOS hysteresis is provided to prevent chattering. September 2011 8 M9999-090911-B [email protected] or (408) 955-1690 Micrel, Inc. SY88063AL Timing Diagram Figure 1. VIS and VID Definition September 2011 9 M9999-090911-B [email protected] or (408) 955-1690 Micrel, Inc. SY88063AL Structure Recommendations Figure 2. Simplified Input Structure Figure 3. Simplified Output Structure Figure 4. LOS Output Structure Figure 5. LOSLVL Setting Circuit September 2011 10 M9999-090911-B [email protected] or (408) 955-1690 Micrel, Inc. SY88063AL Package Information 16-Pin (3mm × 3mm) QFN MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. This information is not intended as a warranty and Micrel does not assume responsibility for its use. Micrel reserves the right to change circuitry, specifications and descriptions at any time without notice. No license, whether express, implied, arising by estoppel or otherwise, to any intellectual property rights is granted by this document. Except as provided in Micrel’s terms and conditions of sale for such products, Micrel assumes no liability whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2010 Micrel, Incorporated. September 2011 11 M9999-090911-B [email protected] or (408) 955-1690