Micrel, Inc. SY88903V 5V/3.3V 1.25Gbps HIGH-SPEED SY88903V LIMITING POST AMPLIFIER FEATURES DESCRIPTION 3.3V and 5V power supply option The SY88903V limiting post amplifier with its high gain and wide bandwidth is ideal for use as a post amplifier in Up to 1.25Gbps operation fiber optic receivers with data rates up to 1.25Gbps. Signals Low noise as small as 5mV can be amplified to drive devices with pp Chatter-free LOS generation PECL inputs. The SY88903V generates a chatter-free, Loss- Open collector TTL LOS output -of-Signal (LOS), open-collector TTL output. The SY88903V is an integrated limiting amplifier intended TTL /EN Input for high-frequency fiber optic applications. The circuit Differential PECL inputs for data connects to typical transimpedance amplifiers found within Single power supply a fiber optics link. The linear signal output from a Designed for use with laser diode driver and transimpedance amplifier can contain significant amounts controller of noise, and may vary in amplitude over time. The SY88903V limiting amplifier quantizes the signal and outputs Available in a tiny 10-pin (3mm 3mm) MSOP a voltage-limited waveform. The /EN pin allows the user to disable the output signal without removing the input signal. The SY88903V incorporates a programmable level detect APPLICATIONS function to identify when the input signal has been lost. This information can be fed back to the /EN input of the 1.25Gbps Gigabit Ethernet device to maintain stability under loss of signal condition. 531Mbps and 1062Mbps Fibre Channel The sensitivity of the level detection can be adjusted using 622Mbps SONET LOS . The LOS voltage can be set by connecting a LVL LVL Gigabit Interface Converter resistor divider between V and V as shown in Figure CC REF 3. Typical Characteristics show the relationship between input level sensitivity and the voltage set on LOS . LVL The LOS output is a TTL open-collector output that requires a pull-up resistor for proper operation, Figure 1. V CC BLOCK DIAGRAM SY88903V 2.5k LOS DIN DOUT Limiting ECL Figure 1. LOS Output with Desired Rise Time Amplifer Buffer DIN DOUT All support documentation can be found on Micrels web site at www.micrel.com. VREF Enable EN VCC Level GND Detect LOS LOSLVL Rev.: F Amendment: /0 M9999-111307 1 Issue Date: November 2007 hbwhelp micrel.com or (408) 955-1690Micrel, Inc. SY88903V PACKAGE/ORDERING INFORMATION (1) Ordering Information /EN 1 10 VCC Package Operating Package Lead DIN 2 9 DOUT Part Number Type Range Marking Finish /DIN 3 8 /DOUT SY88903VKC K10-1 Commercial 903V with Sn-Pb Pb-free bar-line indicator VREF 4 7 LOS (2) LOSLVL 5 6 GND SY88903VKCTR K10-1 Commercial 903V with Sn-Pb Pb-free bar-line indicator SY88903VKG K10-1 Industrial 903V with NiPdAu 10-Pin MSOP (K10-1) Pb-free bar-line indicator Pb-Free (2) SY88903VKGTR K10-1 Industrial 903V with NiPdAu Pb-free bar-line indicator Pb-Free Notes: 1. Contact factory for die availability. Die is guaranteed at T = 25C, DC electricals only. A 2. Tape and Reel. PIN DESCRIPTION Pin Number Pin Name Type Pin Function 1EN TTL Input Output Enable (Active Low). 2 DIN Data Input Data Input. 3 /DIN Data Input Inverting Data Input. 4 VREF Output Reference Voltage Output for LOS Level Set (see Figure 3). 5 LOSLVL Input LOS Limit Set. 6 GND Ground Ground 7 LOS TTL Output Loss-of-Signal Indicator (Active Low). (Open Collector) 8 /DOUT PECL Output Inverting Data Output. 9 DOUT PECL Output Data Output. 10 VCC Power Supply Positive Power Supply. M9999-111307 2 hbwhelp micrel.com or (408) 955-1690