SY88343HL 3.3V, 3.2Gbps CML Limiting Post Amplifier with High-Gain TTL Loss-of-Signal General Description Features The SY88343HL low-power, high-sensitivity, 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 SY88343HL quantizes these signals and outputs CML level waveforms. The SY88343HL operates from a single +3.3V power o o supply, over temperatures ranging from –40 C to +85 C. With its wide bandwidth, high gain, and signals with data rates up to 3.2Gbps and as small as 4mVPP, it can be amplified to drive devices with CML/PECL inputs The SY88343HL generates a high-gain loss-of-signal (LOS) open-collector TTL output. This function has a high-gain input stage for increased LOS sensitivity. 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, 3.5dB LOS hysteresis is provided to prevent chattering. All support documentation can be found on Micrel’s web site at: www.micrel.com. • • • • • • • High input sensitivity: 4mVPP Single 3.3V power supply 155Mbps to 3.2Gbps operation Ideal for multi-rate applications Low-noise CML data outputs High-sensitivity Loss-of-signal (LOS) detection Chatter-free open-collector TTL Loss-of-Signal (LOS) output with internal 4.75kΩ pull-up resistor • TTL /EN input • Programmable LOS level set (LOSLVL) • Available in a tiny (3mm x 3mm) 16-pin QFN package Applications • • • • • • APON, BPON, EPON, GEPON, and GPON SFP/SFF/GBIC optical transceivers Gigabit Ethernet 1X and 2X Fibre Channel SONET/SDH: OC 3/12/24/48 – STM ¼/8/16 Line driver and line receiver Markets • FTTX • Datacom/Telecom 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 August 2007 M9999-082007-A [email protected] or (408) 955-1690 Micrel, Inc. SY88343HL Ordering Information Part Number Package Type Operating Range Package Marking Lead Finish QFN-16 Industrial 343H with Pb-Free bar line indicator NiPdAu Pb-Free QFN-16 Industrial 343H with Pb-Free bar line indicator NiPdAu Pb-Free SY88343HLMG (1) SY88343HLMGTR Note: 1. Tape and Reel. Pin Configuration 16-Pin QFN Pin Description Pin Number Pin Name Type 15 /EN TTL Input: Default is HIGH. 1 DIN Data Input True data input. 4 /DIN Data Input Complementary data input. 6 VREF 14 LOSLVL Input 2, 3, GND, Exposed Pad Ground 7 LOS Open-collector TTL output w/internal 4.75kΩ pull-down resistor 9 /DOUT CML Output Complementary data output. 12 DOUT CML Output True data output. 5, 8, 13, 16 VCC Power Supply 10, 11 August 2007 Pin Function /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 logic HIGH state if left open. Reference Voltage: Bypass with 0.1µF low ESR capacitor from VREF to VCC to stabilize LOSLVL and VREF. 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. Device ground. GND and Exposed pad are to be tied to the same ground plane. Loss-of-Signal: asserts high when the data input amplitude falls below the threshold sets by LOSLVL. Positive power supply. 2 M9999-082007-A [email protected] or (408) 955-1690 Micrel, Inc. SY88343HL 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 VREF Current……………………………-800μA to + 500μA LOSLVL Voltage .............................................. VREF 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 Junction Temperature (TJ) ..................–40°C to +125°C Junction Thermal Resistance QFN (θJA) Still-air ..................................................... 61°C/W QFN (ΨJB) o Junction-to-board .....................................38 C/W DC Electrical Characteristics VCC = 3.0V to 3.6V; RL = 50Ω to V CC; TA = –40°C to +85°C. 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 VREF Reference Voltage VIHCMR Input Common Mode Range Typ 45 VREF VCC = 3.3V Max Units 62 mA VCC V V VCC-0.020 VCC-0.005 VCC VCC-0.475 VCC-0.400 VCC-0.350 V ±80 mV 60 Ω 40 50 VCC-1.28 GND+2.0 V VCC V Max Units TTL DC Electrical Characteristics VCC = 3.0V to 3.6V; RL = 50Ω to V CC; TA = –40°C to +85°C. Symbol Parameter VIH /EN Input HIGH Voltage VIL /EN Input LOW Voltage IIH /EN Input HIGH Current Condition Min 2.0 0.8 V VIN = 2.7V 20 µA VIN = VCC 100 µA IIL /EN Input LOW Current VIN = 0.5V VOH LOS Output HIGH Level VCC > 3.3V, IOH-MAX < 160µA VCC < 3.3V, IOH-MAX < 160µA VOL LOS Output LOW Level Typ IOL = +2mA -300 µA 2.4 V 2.0 V 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. August 2007 3 M9999-082007-A [email protected] or (408) 955-1690 Micrel, Inc. SY88343HL AC Electrical Characteristics VCC = 3.0V to 3.6V; RL = 50Ω to V CC; TA = –40°C to +85°C. Symbol Parameter Condition tr , tf Output Rise/Fall Time (20% to 80%) tJITTER Min Typ Max Note 4 60 120 Deterministic Random Note 5 Note 6 15 5 VID Differential Input Voltage Swing Figure 1 VOD Differential Output Voltage Swing VID > 4mVPP, Figure 1 3 700 800 Units ps psPP psRMS 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 3.0 mVPP LOSDL Low LOS De-assert Level RLOSLVL = 15kΩ, Note 8 4.5 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 2 3.5 dB 5.0 mVPP 7.5 11 2 3.5 4.5 8 12 mVPP dB mVPP 18 23 mVPP 2 3.5 4.5 dB 2 GHz Differential Voltage Gain 40 46 dB Single-ended Small-Signal Gain 34 40 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 de-assert amplitude. August 2007 4 M9999-082007-A [email protected] or (408) 955-1690 Micrel, Inc. SY88343HL Typical Operating Characteristics Functional Characteristics August 2007 5 M9999-082007-A [email protected] or (408) 955-1690 Micrel, Inc. SY88343HL Functional Block Diagram Detailed Description Loss-of-Signal The SY88343HL generates a chatter-free LOS opencollector TTL output with an internal 4.75k Ω pull -up resistor as shown in Figure 4. 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 deasserts the true output signal without removing the input signals. Typically, 3.5dB 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 5. Hysteresis The SY88343HL typically provides 3.5dB LOS electrical hysteresis. By definition, a power ratio measured in dB is 10log (power ratio). Power is 2 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 SY88343HL is an electrical device, this data sheet refers to hysteresis in electrical terms. With 3.5dB LOS hysteresis, a voltage factor of 1.5 is required to assert or de-assert LOS. The SY88343HL high-sensitivity 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 4mVPP can be amplified. Figure 1 shows the allowed input voltage swing. The SY88343HL generates a LOS output. LOSLVL sets the sensitivity of the input amplitude detection. Input Amplifier/Buffer Figure 2 shows a simplified schematic of the SY88343HL’s input stage. The high-sensitivity of the input amplifier allows signals as small as 4mVPP to be detected and amplified. The input amplifier also allows input signals as large as 1800mVPP. Input signals below 6mVpp are linearly amplified with a typical 46dB differential voltage gain. Since it is a limiting amplifier, the SY88343HL outputs typically 800mVPP voltage-limited waveforms for input signals than 6mVPP. Applications requiring the SY88343HL to operate with high-gain should have the upstream TIA placed as close as possible to the SY88343HL’s input pins to ensure the best performance of the device. Output Buffer The SY88343HL’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. August 2007 6 M9999-082007-A [email protected] or (408) 955-1690 Micrel, Inc. SY88343HL Figure 1. VIS and VID Definition August 2007 Figure 2. Input Structure Figure 3. Output Structure Figure 4. Input Structure Figure 5. LOSLVL Setting Circuit 7 M9999-082007-A [email protected] or (408) 955-1690 Micrel, Inc. SY88343HL Package Information PCB Thermal Consideration for 16-Pin QFN Package Package Notes: August 2007 1. Package meets Level 2 qualification. 2. All parts are dry-packaged before shipment. 3. Exposed pad must be soldered to a ground for proper thermal management. 8 M9999-082007-A [email protected] or (408) 955-1690 Micrel, Inc. SY88343HL 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. © 2007 Micrel, Incorporated. August 2007 9 M9999-082007-A [email protected] or (408) 955-1690