5V/3.3V 2.5Gbps HIGH-SPEED LIMITING POST AMPLIFIER Micrel, Inc. DESCRIPTION FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ 3.3V and 5V power supply options Up to 2.5Gbps operation Low noise Chatter-Free LOS Generation Open Collector TTL LOS Output TTL /EN Input Differential PECL inputs for data Single power supply Designed for use with Micrel's Laser Diode Driver and Controller ■ Available in a tiny 10-pin (3mm) MSOP The SY88923V limiting post amplifier with its high gain and wide bandwidth is ideal for use as a post amplifier in fiber-optic receivers with data rates up to 2.5Gbps. Signals as small as 5mVPP can be amplified to drive devices with PECL inputs. The SY88923V generates a chatter-free Loss of Signal (LOS) open collector TTL output. The SY88923V incorporates a programmable level detect function to identify when the input signal has been lost. The LOS output will change from logic “LOW” to logic “HIGH” when input signal is smaller than the swing set by LOSLVL. This information can be fed back to the EN input of the device to maintain stability under loss of signal condition. Using LOSLVL pin, the sensitivity of the level detection can be adjusted. The LOSLVL voltage can be set by connecting a resistor divider between VCC and VREF show in Figure 3. Performance Curves show the relationship between input level sensitivity and the voltage set on LOSLVL. The LOS output is a TTL open collector output that requires a pull-up resistor for proper operation, Figure 1. APPLICATIONS ■ ■ ■ ■ ■ ■ SY88923V SY88923V 1.25Gbps and 2.5Gbps Gigabit Ethernet 531Mbps, 1062Mbps and 2.12Gbps Fibre Channel 622Mbps SONET Gigabit Interface Converter 2.5Gbps SDH/SONET 2.5Gbps Proprietary Links VCC SY88923V LOS 2.5kΩ Figure 1. LOS Output with Desired Rise Time BLOCK DIAGRAM DIN DOUT ECL Buffer Limiting Amplifer /DIN /DOUT VREF Enable /EN VCC Level Detect GND LOS LOSLVL M9999-051706 [email protected] or (408) 955-1690 Rev.: E 1 Amendment: /0 Issue Date: May 2006 Micrel, Inc. SY88923V PACKAGE/ORDERING INFORMATION Ordering Information(1) /EN 1 10 VCC DIN 2 MSOP K10-1 /DIN 3 VREF 4 LOSLVL 5 9 DOUT Part Number Package Type Operating Range Package Marking Lead Finish 8 /DOUT SY88923VKC K10-1 Commercial 923V Sn-Pb 7 LOS SY88923VKCTR(2) K10-1 Commercial 923V Sn-Pb 6 GND SY88923VKG(3) K10-1 Industrial 923V with Pb-Free bar-line indicator Pb-Free NiPdAu SY88923VKGTR(2, 3) K10-1 Industrial 923V with Pb-Free bar-line indicator Pb-Free NiPdAu 10-Pin MSOP (K10-1) Notes: 1. Contact factory for die availability. Dice are guaranteed at TA = 25°C, DC Electricals only. 2. Tape and Reel. 3. Pb-Free package is recommended for new designs. PIN NAMES GENERAL DESCRIPTION Pin Type DIN Data Input Data Input /DIN Data Input Inverting Data Input LOSLVL Input LOS Limit Set /EN TTL Input Output Enable (Active Low) LOS TTL Output (Open Collector) Loss of Signal Indicator (Active High) GND Ground Ground /DOUT PECL Output Inverting Data Output DOUT PECL Output Data Output VCC Power Supply Positive Power Supply VREF Output Reference Voltage Output for LOS Level Set (see Fig. 3) General The SY88923V is an integrated limiting amplifier intended for high-frequency fiber-optic applications. The circuit connects to typical trans-impedance 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 SY88923V 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 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 DOUT, /DOUT Output Voltage (with 50Ω load) VCC –2.5 to VCC +0.3 V /EN Input Voltage 0 to VCC V LOSLVL Input Voltage 0 to VCC V VREF Output Voltage VCC –2.0 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. M9999-051706 [email protected] or (408) 955-1690 2 Micrel, Inc. SY88923V DC ELECTRICAL CHARACTERISTICS VCC = +5V ±10% or +3.3V ±10%, RLOAD = 50Ω to VCC –2V TA = –40°C Symbol Parameter ICC Power Supply Current(1) IIL /EN Input LOW Current TA = 0°C TA = +25°C TA = +85°C Min. Max. Min. Max. Min. Typ. Max. Min. Max. Unit — — 40 40 — — 40 40 — — 30 28 40 40 — — 45 45 mA –0.3(6) — –0.3(6) — –0.3(6) — — –0.3(6) — mA — — 20(4) 100(5) — — — — 20(4) 100(5) — — 20(4) 100(5) µA 5V 3.3V IIH /EN Input HIGH Current — — 20(4) 100(5) VCMR Common Mode Range GND +2.0 VCC GND +2.0 VCC GND +2.0 — VCC GND +2.0 VCC V Voffset Differential Output Offset — ±100 — ±100 — ±17 ±100 — ±100 mV LOSLVL LOSLVL Level VREF VCC VREF VCC VREF — VCC VREF VCC V — 0.5 — 0.5 — — 0.5 — 0.5 V — 100 — 100 — — 100 — 100 uA VOL LOS Output Low Level(2) Leakage(3) IOH LOS Output VOH DOUT and /DOUT HIGH Output VCC –1085 VCC –880 VCC –1025 VCC –880 VCC –1025 VCC –955 VCC –880 VCC –1025 VCC –880 mV VOL DOUT and /DOUT LOW Output VCC –1830 VCC –1555 VCC –1810 VCC –1620 VCC –1810 VCC –1705 VCC –1620 VCC –1810 VCC –1620 mV VREF Reference Supply VCC –1.38 VCC –1.26 VCC –1.38 VCC –1.26 VCC –1.38 VCC –1.32 VCC –1.26 VCC –1.38 VCC –1.26 V IREF VREF Output Current –0.8 0.5 –0.8 0.5 –0.8 — 0.5 –0.8 0.5 mA 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 — 0.8 V Notes: 1. No output load 2. IOL = + 2mA 3. VOH = 5.5V 4. VIN = 2.7V 5. VIN = VCC 6. VIN = 0.5V AC ELECTRICAL CHARACTERISTICS VCC = +5V ±10% or +3.3V ±10%, RLOAD = 50Ω to VCC –2V TA = –40°C Symbol Parameter TA = 0°C TA = +25°C TA = +85°C Min. Max. Min. Max. Min. Typ. Max. Min. Max. Unit PSRR Power Supply(1) Rejection Ratio — — — — — 35 — — — dB VID Input Voltage Range 5 1800 5 1800 5 — 1800 5 1800 mVPP VOD Differential Output Voltage Swing(2) — — — — — — — — — — 700 300 — — — — — — mV mV tOFFL LOS Release Time(3) Minimum Input — 0.5 — 0.5 — 0.1 0.5 — 0.5 µs tONL LOS Assert Time(3) — 0.5 — 0.5 — 0.2 0.5 — 0.5 µs Conditions Input referred, 55MHz VID = 15mVPP VID = 5mVPP tOFFH LOS Release Maximum Input — 0.5 — 0.5 — 0.1 0.5 — 0.5 µs VSR LOS Sensitivity Range 5 50 5 50 5 — 50 5 50 mVPP 223-1 pattern HYS LOS Hysteresis 2 8 2 8 2 4.6 8 2 8 dB 223-1 pattern tr, tf Output Rise/Fall Time — — 175 — — — 175 — — — 150 trin,tfin 175 — — — 175 — ps VID > 100mVPP VID < 100mVPP Time(4) 3. Input is a 200MHz square wave, tr < 300ps, 8mVPP. 4. Input is a 200MHz square wave, tr < 300ps, 1.8VPP. Notes: 1. Input referred noise = RMS output noise/low frequency gain. 2. Input is a 622MHz square wave. M9999-051706 [email protected] or (408) 955-1690 3 Micrel, Inc. SY88923V DESIGN PROCEDURE Output Termination The SY88923V outputs must be terminated with a 50Ω load to VCC – 2V (or Thevenin equivalent). The SY88923V 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. Layout and PCB Design Since the SY88923V 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 the power supply. VCC 0.1µF DIN+ R1 0.1µF 50Ω DIN– LOSLVL 50Ω R2 VREF VREF 0.1µF Figure 2. Differential Input Configuration Figure 3. LOSLVL Circuit Notes: R2 × 1.32V LOSLVL = VCC -1.32V + R1 + R2 R1 + R2 ≥ 2.6kΩ M9999-051706 [email protected] or (408) 955-1690 4 Micrel, Inc. SY88923V PERFORMANCE CURVE INPUT LEVEL (mVpp) 100 De-Assert Assert 0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 LOSLVL = VCC — V (V) LOS Assert and De-Assert Levels vs LOSLVL 90 80 70 60 3.3V TA = 25¡C 2.5Gbps Pattern 27-1 50 40 30 De-Assert 20 10 0 INPUT LEVEL (mVpp) 50 40 30 20 10 0 100 3.3V TA = 25¡C 2.5Gbps Pattern 223-1 90 80 70 60 0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 LOSLVL = VCC — V (V) M9999-051706 [email protected] or (408) 955-1690 5 5.0V TA = 25¡C 2.5Gbps Pattern 223-1 50 40 30 20 10 0 De-Assert Assert 0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 LOSLVL = VCC — V (V) LOS Assert and De-Assert Levels vs LOSLVL 5.0V TA = 25¡C 2.5Gbps Pattern 27-1 80 70 60 50 De-Assert 40 30 20 10 0 Assert LOS Assert and De-Assert Levels vs LOSLVL 90 80 70 60 100 90 INPUT LEVEL (mVpp) INPUT LEVEL (mVpp) 100 LOS Assert and De-Assert Levels vs LOSLVL Assert 0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 LOSLVL = VCC — V (V) Micrel, Inc. SY88923V 10-PIN MSOP (K10-1) Rev. 00 MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 TEL + 1 (408) 944-0800 FAX + 1 (408) 474-1000 WEB USA http://www.micrel.com The information furnished by Micrel in this datasheet 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 at Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2006 Micrel, Incorporated. M9999-051706 [email protected] or (408) 955-1690 6