SY88313BL 3.3V, 3.2Gbps CML Low-Power Limiting Post Amplifier with TTL Loss-of-Signal General Description The SY88313BL low-power limiting post amplifier is designed for use in fiber-optic receivers. The device connects to typical transimpedance amplifiers (TIAs). The linear signal output from TIAs can contain significant amounts of noise and may vary in amplitude over time. The SY88313BL quantizes these signals and outputs CML-level waveforms. The SY88313BL operates from a single +3.3V ±10% supply, over temperatures ranging from –40°C to +85°C. With its wide bandwidth and high gain, signals with data rates up to 3.2Gbps, and as small as 10mVPP, can be amplified to drive devices with CML inputs or ACcoupled CML/PECL inputs. The SY88313BL 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 bar 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 maintain output stability under a loss-of-signal condition. Typically, 3.4dB LOS hysteresis is provided to prevent chattering. Datasheet and support documentation cab be found on Micrel’s web site at: www.micrel.com. Features • Single 3.3V power supply • DC to 3.2Gbps operation • Low-noise CML data outputs • Chatter-free Open-Collector TTL loss-of-signal (LOS) output with internal 4.75kΩ pull-up resistor • TTL /EN input • Internal 50Ω input termination • Programmable LOS level set (LOSLVL) • Ideal for multi-rate applications • Available in a tiny 10-pin EPAD MSOP and 16-pin QFN package Applications • APON/BPON, GEPON, EPON, and GPON • Gigabit Ethernet • Fibre Channel • OC-3/12/24/48 SONET/SDH • High-gain line driver and line receiver • Low-gain TIA interface Markets • FTTP/FTTH • Datacom/Telecom • Optical Transceivers _______________________________________________________________________________________________________ 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 February 2007 M9999-021207-B [email protected] or (408) 955-1690 Micrel, Inc. SY88313BL Ordering Information(1) Part Number Package Type Operating Range Package Marking Lead Finish SY88313BLMG QFN-16 Industrial 313B with Pb-Free bar-line indicator NiPdAu Pb-Free QFN-16 Industrial 313B with Pb-Free bar-line indicator NiPdAu Pb-Free K10-2 Industrial 313B with Pb-Free bar-line indicator Matte-Sn Pb-Free K10-2 Industrial 313B with Pb-Free bar-line indicator Matte-Sn Pb-Free (2) SY88313BLMGTR SY88313BLEY (2) SY88313BLEYTR Notes: 1. Contact factory for die availability. Dice are guaranteed at TA = 25C, DC Electricals only. 2. Tape and Reel. Pin Configuration 16-Pin QFN February 2007 10-Pin EPAD-MSOP (K10-2) 2 M9999-021207-B [email protected] or (408) 955-1690 Micrel, Inc. SY88313BL Pin Description Pin Number (MSOP) Pin Number (QFN) Pin Name Type 1 15 /EN TTL Input: Default is high. 2 1 DIN Data Input True data input with 50Ω termination to VREF. 3 4 /DIN Data Input Complementary data input with 50Ω termination to VREF. 4 6 VREF 5 14 LOSLVL Input: Default is maximum sensitivity 6 Exposed Pad 2, 3, 10, 11 Exposed Pad GND Ground 7 7 LOS Open Collector TTL Output with Internal 4.75kΩ pull-up resistor 8 9 /DOUT CML Output Complementary data output. 9 12 DOUT CML Output True data output. 10 5, 8, 13, 16 VCC Power Supply February 2007 Pin Function Enable Bar: De-assert true data output when high. Reference Voltage: Placing a capacitor here to VCC helps stabilize LOSLVL. Loss-of-Signal Level Set: A resistor from this pin to VCC sets the threshold for the data input amplitude at which the LOS output will be asserted. Device ground. Exposed pad must be connected to PCB ground plane. Loss-of-Signal: Asserts high when the data input amplitude falls below the threshold set by LOSLVL. Positive power supply. 3 M9999-021207-B [email protected] or (408) 955-1690 Micrel, Inc. SY88313BL Operating Ratings(2) Absolute Maximum Ratings(1) Supply Voltage (VCC) ........................... +3.0V to +3.6V Ambient Temperature (TA).................. –40°C to +85°C Junction Temperature (TJ) ................ –40°C to +120°C (3) Junction Thermal Resistance QFN (θJA) Still-air .................................................. 61°C/W (ψJB) .............................................................. 38°C/W Supply Voltage (VCC) ..................................... +0V to +4.0V Input Voltage (DIN, /DIN) .......................................0 to VCC Output Current (IOUT) .............................................. ± 25mA /EN Voltage ............................................................0 to VCC VREF Current ............................................................ ±1mA LOSLVL Voltage............................................... VREF to VCC Lead Temperature (soldering, 20sec.) ................... +260°C Storage Temperature (Ts) ........................ -65°C to +150°C EPAD-MSOP (θ JA) Still-air .................................................. 38°C/W (ψJB) .............................................................. 22°C/W DC Electrical Characteristics VCC = 3.0V to 3.6V; RL = 50Ω to VCC; TA = –40°C to +85°C, unless otherwise stated. Symbol Parameter Condition Min ICC Power Supply Current No output load. LOSLVL LOSLVL Voltage VOH CML Output HIGH Voltage VOL CML Output LOW Voltage VOFFSET Differential Output Offset ZO Single-Ended Output Impedance 40 ZI Single-Ended Input Impedance 40 VREF Reference Voltage Typ 47 VREF VCC = 3.3V Max Units 65 mA VCC V V VCC-0.020 VCC-0.005 VCC VCC-0.475 VCC-0.400 VCC-0.350 V ±80 mV 50 60 Ω 50 60 Ω VCC-1.28 V TTL DC Electrical Characteristics VCC = 3.0V to 3.6V; RL = 50Ω to VCC; TA = –40°C to +85°C, unless otherwise stated. Symbol Parameter Condition Min Typ Max Units 0.8 V 20 100 µA µA VIH /EN Input HIGH Voltage VIL /EN Input LOW Voltage 2.0 V IIH /EN Input HIGH Current VIN = 2.7V VIN = VCC IIL /EN Input LOW Current VIN = 0.5V -0.3 mA VOH LOS Output HIGH Level VCC ≥ 3.3V, IOH (max) <160µA VCC < 3.3V, IOH (max) <160µA 2.4 2.0 V V VOL LOS Output LOW Level IOL = +2mA 0.5 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 rating 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 device’s most negative potential (GND) on the PCB. ψJB uses 4-layer (θJA) in still-air number, unless otherwise stated. February 2007 4 M9999-021207-B [email protected] or (408) 955-1690 Micrel, Inc. SY88313BL AC Electrical Characteristics VCC = 3.0V to 3.6V; RLOAD = 50Ω to VCC; TA = –40°C to +85°C. Symbol Parameter Condition Typ Max Units tr , tf Output Rise/Fall Time (20% to 80%) Note 4 Min 60 120 ps tJITTER Deterministic Note 5 15 Random Note 6 VID Differential Input Voltage Swing Figure 1 10 VOD Differential Output Voltage Swing VID > 18mVPP Figure 1 700 psPP psRMS 5 800 1800 mVPP 950 mVPP TOFF LOS Release Time 2 10 µs TON LOS Assert Time 2 10 µs LOSAL Low LOS Assert Level RLOSLVL = 15kΩ, Note 8 7.8 mVPP LOSDL Low LOS De-assert Level RLOSLVL = 15kΩ, Note 8 12 mVPP HYSL Low LOS Hysteresis RLOSLVL = 15kΩ, Note 7 LOSAM Medium LOS Assert Level RLOSLVL = 5kΩ, Note 8 LOSDM Medium LOS De-assert Level RLOSLVL = 5kΩ, Note 8 HYSM Medium LOS Hysteresis RLOSLVL = 5kΩ, Note 7 LOSAH High LOS Assert Level RLOSLVL = 100Ω, Note 8 LOSDH High LOS De-assert Level RLOSLVL = 100Ω, Note 8 HYSH High LOS Hysteresis RLOSLVL = 100Ω, Note 7 B-3dB 3dB Bandwidth AV(Diff) S21 10 3.7 dB 17 mVPP 25 40 mVPP 2 3.3 4.5 dB 30 45 mVPP 69 95 mVPP 2 3.7 4.5 dB 2 GHz Differential Voltage Gain 32 38 dB Single-ended Small-Signal Gain 26 32 dB Notes: 4. Amplifier in limiting mode. Input is a 200MHz square wave. 5. Deterministic jitter measured using 3.2Gbps K28.5 pattern, VID = 10mVPP. 6. Random jitter measured using 3.2Gbps K28.7 pattern, VID = 10mVPP. 7. 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 2dB-4.5dB, shown in the AC characteristics table, will be 1dB-3dB Optical Hysteresis. 8. See “Typical Operating Characteristics” for a graph showing how to choose a particular RLOSLVL for a particular LOS assert and its associated deassert amplitude. February 2007 5 M9999-021207-B [email protected] or (408) 955-1690 Micrel, Inc. SY88313BL Typical Characteristics February 2007 6 M9999-021207-B [email protected] or (408) 955-1690 Micrel, Inc. SY88313BL Functional Diagram Detailed Description The SY88313BL low-power limiting post amplifier operates from a single +3.3V power supply, over o o temperatures from –40 C to +85 C. Signals with data rates up to 3.2Gbps and as small as 10mVPP can be amplified. Figure 1 shows the allowed input voltage swing. The SY88313BL generates a LOS output. LOSLVL sets the sensitivity of the input amplitude detection. Input Amplifier/Buffer Figure 2 shows a simplified schematic of the SY88313BL’s input stage. The high-sensitivity of the input amplifier allows signals as small as 10mVPP to be detected and amplified. The input amplifier also allows input signals as large as 1800mVPP. Input signals are linearly amplified with a typical 38dB differential voltage gain. Since it is a limiting amplifier, the SY88313BL outputs typically 800mVPP voltage-limited waveforms for input signals that are greater than 12mVPP. Applications requiring the SY88313BL to operate with high-gain should have the upstream TIA placed as close as possible to the SY88313BL’s input pins to ensure the best performance of the device. Output Buffer The SY88313BL’s CML output buffer is designed to drive 50Ω lines. The output buffer requires appropriate termination for proper operation. An external Ω 50 resistor to VCC for each output pin provides this. Figure 3 shows a simplified schematic of the output stage. February 2007 Loss-of-Signal The SY88313BL generates a chatter-free LOS opencollector TTL output with an internal 4.75k Ω pull -up resistor as shown in Figure 5. LOS is used to determine that the input amplitude is large enough to be considered 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 bar (EN) input to maintain output stability under a loss of signal condition. /EN de-asserts the true output signal without removing the input signals. Typical 3.4dB LOS hysteresis is provided to prevent chattering. Loss-of-Signal 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 VREF. The external resistor creates a voltage divider between VCC and VREF as shown in Figure 6. Hysteresis The SY88313BL provides typically 3.4dB LOS electrical hysteresis. By definition, a power ratio measured in dB 2 is 10log (power ratio). Power is calculated as V IN/R for an electrical signal. Hence, the same ratio can be stated as 20log (voltage ratio). While in linear mode, the electrical voltage input changes linearly with the optical power and therefore, the ratios change linearly. Thus, the optical hysteresis in dB is half the electrical hysteresis in dB given in the data sheet. Since the SY88313BL is an electrical device, this data sheet refers to hysteresis in electrical terms. With 3.4dB LOS hysteresis, a voltage factor of 1.5 is required to assert or de-assert LOS. 7 M9999-021207-B [email protected] or (408) 955-1690 Micrel, Inc. SY88313BL Figure 1. VIS and VID Definition Figure 2. Input Structure Figure 3. Output Structure Figure 5. LOS Output Structure Figure 4. Power Supply Current Measurement February 2007 Figure 6. LOSLVL Setting Circuit 8 M9999-021207-B [email protected] or (408) 955-1690 Micrel, Inc. SY88313BL Package Information 10-Pin EPAD MSOP (K10-2) February 2007 9 M9999-021207-B [email protected] or (408) 955-1690 Micrel, Inc. SY88313BL 16-Pin 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 The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. 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. © 2005 Micrel, Incorporated. February 2007 10 M9999-021207-B [email protected] or (408) 955-1690