5V/3.3V 3.2Gbps HIGH-SPEED LIMITING POST AMPLIFIER DESCRIPTION FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ > 3.2Gbps operation Low noise CML Data Outputs Chatter-Free LOS generation Open Collector TTL LOS output TTL /EN Input Differential PECL inputs for data Single 3.3V or 5V power supply Designed for use with SY88922V and SY88905 Available in a tiny 10-pin (3mm) MSOP The SY88993AV limiting post amplifier with its high and wide bandwidth is ideal for use as a post amplifier in fiberoptic receivers with data rates up to 3.2Gbps. Signals as small as 4mVp-p can be amplified to drive devices with CML inputs or AC coupled PECL inputs. The SY88993AV generates a chatter-free Loss of Signal (LOS) open collector TTL output. The SY88993AV incorporates a programmble level detect function to identify when the input signal has been lost. This information can be fed back to the /EN input of the device to maintain stability under loss of signal conditions. Using LOSLVL pin the sensitivity of the level detect can be adjusted. The LOSLVL voltage can be set by connecting a resistor divider between VCC and VREF, Figure 3. BLOCK DIAGRAM PIN CONFIGURATION /EN 1 10 VCC DIN 2 9 DOUT /DIN 3 SY88993AV MSOP K10-1 DIN 8 /DOUT VREF 4 7 LOS LOSLVL 5 6 GND DOUT Limiting Amplifer CML Buffer DIN DOUT VREF Enable VCC EN Level Detect GND APPLICATIONS ■ 1.25Gbps and 2.1Gbps Gigabit Ethernet ■ 531Mbps, 1062Mbps and 2.5Gbps SONET/SDH Fibre Channel ■ 622Mbps ■ Gigabit interface converter (GBIC) ■ Small Form Factor Trancievers ■ Parallel 10G Ethernet LOS LOSLVL VCC SY88993AV LOS 4.7k to 10k Rev.: A 1 Amendment: /1 Issue Date: October, 2000 SY88993AV Micrel PIN NAMES Pin GENERAL DESCRIPTION Type General The SY88993AV is an integrated limiting amplifier intended for high-frequency fiber-optic applications. The circuit connects to typical transimpedance amplifiers found within a fiber-optics link. The linear signal output from a transimpedance amplifier can contain significant amounts of noise, and may vary in amplitude over time. The SY88993AV limiting amplifier quantizes the signal and outputs a voltage-limited waveform. The /EN pin allows the user to disable the output signal without removing the input signal. Function DIN Data Input Data Input /DIN Data Input Inverting Data Input LOSLVL Input Loss of Signal Level Set /EN TTL Input Output Enable (Active Low) LOS TTL Output (Open Collector) Loss of Signal Indicator (Active High) GND Ground Ground DOUT CML Output Data Output /DOUT CML Output Inverting Data Output VCC Power Supply Positive Power Supply VREF Output Reference Voltage Output for LOS Level Set (see Fig. 3) ABSOLUTE MAXIMUM RATINGS(1) Symbol Rating Value Unit VCC Power Supply Voltage 0 to +7.0 V DIN, /DIN Input Voltage 0 to VCC V TA Operating Temperature Range –40 to +85 °C Tstore Storage Temperature Range –55 to +125 °C NOTE: 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 RATlNG conditions for extended periods may affect device reliability. 2 SY88993AV Micrel DC ELECTRICAL CHARACTERISTICS VCC = +3.3V ±10% or +5V ±10%, RLOAD = 50Ω to VCC TA = –40°C Symbol ICC Parameter Power Supply Current(1) TA = 0°C TA = +25°C TA = +85°C Min. Max. Min. Max. Min. Typ. Max. Min. Max. Unit 5.0V — 55 — 55 — 43 55 — 65 mA 3.3V — 40 50 — 60 mA — mA 50 — 50 — — –0.3(4) — –0.3(4) — — –0.3(4) IIL /EN Input LOW Current –0.3(4) IIH /EN Input HIGH Current — — 20(5) 100(6) — — 20(5) 100(6) — — — — 20(5) 100(6) — — 20(5) 100(6) µA IOH LOS Output Leakage(2) — 100 — 100 — — 100 — 100 uA — ±80 — ±80 — ±9 ±80 — ±80 mV GND±2 VCC–0.2 GND±2 VCC–0.2 GND±2 VCC–0.2 V VOFFSET Differential Output Offset VCMR Common Mode Range GND±2 VCC–0.2 LOSLVL LOSLVL Level VOL LOS Output Low Level(3) VREF Reference Voltage VIH /EN Input HIGH Voltage 2.0 — 2.0 — 2.0 — — 2.0 — V VIL /EN Input LOW Voltage — — 0.8 — 0.8 — — 0.8 — V VREF VCC VREF VCC VREF — VCC VREF VCC V — 0.5 — 0.5 — — 0.5 — 0.5 V VCC –1.38 VCC –1.26 VCC –1.38 VCC –1.26 VCC –1.38 NOTES: 1. No output load. VCC = 5V ±10% or 3.3V ±10% 2. VOH = 5.5V. 3. IOL = +2mA. 4. VIN = 0.5V 5. VIN = 2.7V 6. VIN = VCC 3 VCC –1.32 VCC –1.26 VCC –1.38 VCC –1.26 V SY88993AV Micrel AC ELECTRICAL CHARACTERISTICS VCC = +3.3V ±10% or +5V ±10%, RLOAD = 50Ω to VCC TA = –40°C Symbol HYS Parameter TA = 0°C TA = +25°C TA = +85°C Min. Max. Min. Max. Min. Typ. Max. Min. Max. Unit LOS Hysteresis 2 8 2 8 2 4.6 8 2 8 dB Supply(1) PSRR Power Rejection Ratio — — — — — 35 — — — dB tOFFL LOS Release Time(2) Minimum Input — 0.5 — 0.5 — 0.1 0.5 — 0.5 µs tOFFH LOS Release Time(2) Maximum Input — 0.5 — 0.5 — 0.1 0.5 — 0.5 µs tONL LOS Assert Time(2) — 0.5 — 0.5 — 0.2 0.5 — 0.5 µs tr, tf Output(3) Differential Rise/Fall Time (20%-80%) — 120 — 120 — 60 120 — 120 ps VID Input Voltage Range 4 1800 4 1800 4 — 1800 4 1800 mVp-p VOD Differential Output Voltage Swing(4) — 600 — 600 — 800(5) 1200 600 — mVp-p VSR LOS Sensitivity Range 4 50 4 50 4 — 50 4 50 mVp-p VCC –20 VCC VCC –20 VCC VCC –20 VCC –5 VCC VCC –20 VCC mV — VCC –300 mV Output Spec (DOUT and /DOUT) VOH HIGH Level Output Voltage VOL LOW Level Output(6) ß — VCC –300 — VCC –300 — ZO Single-Ended Output(7) Impedance 40 60 40 60 40 50 60 40 60 Ω VCC –400 VCC –300 Input Spec (DIN and /DIN) AV(Diff) Differential Voltage Gain — — — — — 39 — — — dB B–3dB 3dB Bandwidth — — — — — 2.5 — — — GHz S21 Single-Ended Small Signal-Gain 26 — 26 — 26 33 — 26 — dB NOTES: 1. Input referred noise = RMS output noise/low frequency gain. Input referred, 55MHz. 2. Input is a 200MHz square wave, tr < 300ps, 1.8Vp-p. 3. With input signal VID > 50mVp-p with 50Ω load. 4. Input is a 200MHz square wave, tr < 300ps, 50Ω load. 5. VID > 5mVp-p. 6. Output levels are based on 50Ω impedance. If the load impedance is different, the output level will be changed. 7. See output structure. 4 SY88993AV Micrel PERFORMANCE CURVE LOS Assert and Deassert Levels vs LOSLVL LOS Assert and Deassert Levels vs LOSLVL 100 3.3V TA = 25°C 2.5Gbps Pattern 223-1 90 80 70 60 50 INPUT LEVEL (mVp-p) INPUT LEVEL (mVp-p) 100 40 30 20 10 0 0 70 60 50 40 30 20 10 0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 LOSLVL = VCC – V (V) 5.0V TA = 25°C 2.5Gbps Pattern 223-1 90 80 0 Figure 4. Figure 5. LOS Assert and Deassert Levels vs LOSLVL LOS Assert and Deassert Levels vs LOSLVL 100 3.3V TA = 25°C 2.5Gbps Pattern 27-1 90 80 70 60 50 INPUT LEVEL (mVp-p) INPUT LEVEL (mVp-p) 100 40 30 20 10 0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 LOSLVL = VCC – V (V) 0 70 60 50 40 30 20 10 0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 LOSLVL = VCC – V (V) Figure 6. 5.0V TA = 25°C 2.5Gbps Pattern 27-1 90 80 0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 LOSLVL = VCC – V (V) Figure 7. 5 SY88993AV Micrel APPLICATION NOTE Output Termination The SY88993AV outputs must be terminated with a 50Ω load to VCC. 50Ω 50Ω 50Ω Layout and PCB Design Since the SY88993AV is a high-frequency component, performance can largely be determined by board layout and design. A common problem with high-gain amplifiers is feedback from the large swing outputs to the input via power supply. The SY88993AV ground pin should be connected to the circuit board ground. Use multiple PCB vias close to the part to connect to ground. Avoid long, inductive runs which can degrade performance. ESD STRUCTURE VCC VCC DOUT Z0 = 50Ω /DOUT Z0 = 50Ω 16mA VCC GND ESD STRUCTURE Figure 2. Differential Output Configuration 22nF DIN VCC /DIN 50Ω 50Ω 22nF R1 LOSLVL R2 VREF 0.1µF GND VREF Figure 1. Differential Input Configuration NOTES: 1. Resistor Divider = R2/ (R1 + R2) 2. R1 + R2 ≥ 5kΩ Figure 3. LOSLVL Circuit PRODUCT ORDERING CODE 6 Ordering Code Package Type Operating Range SY88993AVKC K10-1 Commercial 50Ω SY88993AV Micrel APPLICATION EXAMPLE FOR 3-CHIP SET SOLUTION GBIC Terminal TX_DATA+ TX_DATA– TX_FAULT VCC DIN /DIN /EN VCC VREF RSET SY88922 GND 200Ω 68Ω RSER IBIAS SET 20kΩ 0.1µF DIN /DIN 0.1µF IBIAS Laserdiode IBIAS FB VCC 2MΩ 0.1µF 1000pF VCC Laser Module MD RWIN VCCDET 22nF 22nF From Transimpedance Amp. 0.1µF Photodiode VCC OUT /OUT 20kΩ VCC 20kΩ ILIMIT SET SY88904 IPIN SET VCC 20kΩ VREF 0.1µF TX_OUT TX_FAULT TX_DISABLE GND /EN SY88993V VREF 20KΩ 7 68Ω LOSOUT LOSIN LOS DOUT /DOUT LOSLVL VCC 50Ω TX_DISABLE RX_LOS RX_DATA+ RX_DATA– GND 0.1µF 50Ω 0.01µF 200Ω 0.01µF 0.01µF 0.01µF SY88993AV Micrel 10 LEAD MSOP (K10-1) Rev. 00 8 SY88993AV Micrel MICREL-SYNERGY TEL 3250 SCOTT BOULEVARD + 1 (408) 980-9191 FAX SANTA CLARA + 1 (408) 914-7878 WEB CA 95054 USA http://www.micrel.com This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc. © 2000 Micrel Incorporated 9