description 3.3v and 5v power supply options up to 1.5gbps operation low power low noise chatter-free /los generation pecl /los output ttl /en input differential pecl inputs for data /en input is ttl with internal 27k pull up single power supply designed for use with micrel-synergy laser diode driver and controller available in a tiny 10-pin (3mm) msop the SY88913V 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 1.5gbps. signals as small as 5mvp-p can be amplified to drive devices with pecl inputs. the SY88913V generates a chatter-free pecl loss of signal (/los) output. the SY88913V 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 los lvl pin the sensitivity of the level detect can be adjusted. the los lvl voltage can be set by connecting a resistor divider between v cc and v ref , figure 2. figure 3 and 4 show the relationship between input level sensitivity and the voltage set on los lvl . features 5v/3.3v 1.25gbps high-speed limiting post amplifier SY88913V final applications 1.25gbps gigabit ethernet 531mbps and 1062mbps fibre channel 622mbps sonet gigabit interface converter pin configuration block diagram 1 /en din /din vref loslvl 10 vcc dout /dout /los gnd 9 8 7 6 2 3 4 5 msop k10-1 limiting amplifer ecl buffer gnd enable level detect /en los d in /d in v ref v cc los lv l d out /d out 1 rev.: b amendment: /0 issue date: august 2000
2 SY88913V micrel general the SY88913V 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 SY88913V limiting amplifier quantizes the signal and outputs a voltage-limited waveform. the ttl /en pin allows the user to disable the signal without removing the input signal. general description pin type function d in data input data input /d in data input inverting data input los lvl input loss of signal level set /en ttl input output enable (active low) /los pecl output loss of signal indicator (active low) gnd ground ground d out pecl output data output /d out pecl output inverting data output v cc power supply positive power supply v ref output reference voltage output for los level set (see fig. 2) pin names symbol rating value unit v cc power supply voltage 0 to +7.0 v d in , /d in input voltage 0 to v cc v d out , /d out , /los output voltage (with 50 ? load) v cc ?.5 to v cc +0.3 v los lvl input voltage 0 to v cc v v ref output voltage v cc ?.0 to v cc v t a operating temperature range ?0 to +85 c t store storage temperature range ?5 to +125 c absolute maximum ratings (1) note: 1. permanent device damage may occur if absolute maximum ratings are exceeded. this is a stress rating only and functional oper ation is not implied at conditions other than those detailed in the operational sections of this data sheet. exposure to absolute maximum ratlng co nditions for extended periods may affect device reliability.
3 SY88913V micrel t a = ?0 ct a = 0 ct a = +25 ct a = +85 c symbol parameter min. max. min. max. min. typ. max. min. max. unit i cc power supply 5v 35 35 21 35 40 ma current (1) 3.3v 35 35 23 35 40 i il /en input low current ?.3 (5) ?.3 (5) ?.3 (5) ?.3 (5) ?a i ih /en input high current ?0 (2) ?0 (2) 20 (2) ?0 (2) a 100 (3) 100 (3) 100 (3) 100 (3) v cmr common mode range gnd +2.0 v cc ?.0 gnd +2.0 v cc ?.0 gnd +2.0 v cc ?.0 gnd +2.0 v cc ?.0 v v offset differential output offset 100 100 40 100 100 mv los lvl los lvl level v ref v cc v ref v cc v ref ? cc v ref v cc v v oh d out and /d out v cc ?085 v cc ?80 v cc ?025 v cc ?80 v cc ?025 v cc ?55 v cc ?80 v cc ?025 v cc ?80 mv high output v ol d out and /d out v cc ?830 v cc ?555 v cc ?810 v cc ?620 v cc ?810 v cc ?705 v cc ?620 v cc ?810 v cc ?620 mv low output v ref reference supply (4) v cc ?.38 v cc ?.26 v cc ?.38 v cc ?.26 v cc ?.38 v cc ?.32 v cc ?.26 v cc ?.38 v cc ?.26 v v ih /en input high voltage 2.0 2.0 2.0 2.0 v v il /en input low voltage 0.8 0.8 0.8 0.8 v notes: 1. no output load. 2. v in = 2.7v. 3. v in = v cc . dc electrical characteristics v cc = +3.3v 10% or +5v 10%, r load = 50 ? to v cc ?v 4. i ref must be limited to be within ?.8ma (source) and 0.5ma (sink). 5. v in = 0.5v. t a = ?0 ct a = 0 ct a = +25 ct a = +85 c symbol parameter min. max. min. max. min. typ. max. min. max. unit conditions psrr power supply (1) 35 db input referred, rejection ratio 55mhz v id input voltage range 5 1800 5 1800 5 1800 5 1800 mvp-p v od differential output 700 mv v id = 15mvp-p voltage swing (2) 200 200 200 250 200 mv v id = 5mvp-p t offl /los release time (3) 0.5 0.5 0.1 0.5 0.5 s minimum input t onl /los assert time (3) 0.5 0.5 0.2 0.5 0.5 s t offh /los release time (4) 0.5 0.5 0.1 0.5 0.5 s maximum input v sr /los sensitivity range 5 50 5 50 5 50 5 50 mvp-p hys /los hysteresis 2 8 2 8 2 4.6 8 2 8 db t r , t f output rise/fall time 260 260 170 260 260 ps v id > 100mvp-p t rin ,t fin v id < 100mvp-p ac electrical characteristics v cc = +3.3v 10% or +5v 10%, r load = 50 ? to v cc ?v notes: 1. input referred noise = rms output noise/low frequency gain. 2. input is 622mhz square wave. 3. input is a 200mhz square wave, tr < 300ps, 8mvp-p. 4. input is a 200mhz square wave, tr < 300ps, 1.8vp-p.
4 SY88913V micrel product ordering code ordering package operating code type range SY88913Vkc k10-1 commercial output termination the SY88913V outputs must be terminated with a 50 ? load to v cc ?v (or thevenin equivalent). layout and pcb design since the SY88913V 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. application note r1 r2 v cc los lv l v ref figure 2. los lvl circuit notes: los lvl = v cc 1.32 + r1 + r2 5k ? 50 ? 50 ? 0.1 f 0.1 f 0.1 f d in+ d in v ref figure 1. differential input configuration the SY88913V 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. r2 1.32 r1 + r2
5 SY88913V micrel performance curve 0 10 20 30 40 50 60 70 80 90 100 0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 input level (mvp-p) los lvl = v cc v (v) los assert and deassert levels vs los lvl 3.3v t a = 25 c 1.25gbps pattern 2 7 -1 0 10 20 30 40 50 60 70 80 90 100 0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 input level (mvp-p) los lvl = v cc v (v) los assert and deassert levels vs los lvl 5.0v t a = 25 c 1.25gbps pattern 2 7 -1 figure 3. 3.3v los assert and deassert levels vs. los lvl figure 4. 5.0v los assert and deassert levels vs. los lvl
6 SY88913V micrel 10 lead msop (k10-1) rev. 00 micrel-synergy 3250 scott boulevard santa clara ca 95054 usa tel + 1 (408) 980-9191 fax + 1 (408) 914-7878 web http://www.synergysemi.com 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 an y 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 pat ent right of micrel inc. ? 2000 micrel incorporated
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