1 mlo tm rf-dc smt crossover general description the mlo tm smt rf-dc crossover is a very low profile crossover that intersects an rf and dc circuit trace in an smt package. the rf-dc crossover is a low cost solution for applications where a critical rf circuit trace intersects a dc circuit pre- cluding the need for an expensive multilayer printed circuit board. the smt pack- age can support frequencies up to 6 ghz. mlo tm crossovers have been subjected to jedec reliability standards and 100% electrically tested. the rf-dc crossovers are available in nisn. features ? dc C 6.0 ghz ? rf C dc crossover ? low loss ? dc isolation ? surface mountable ? tape and reel ? 100% tested applications ? mobile communications ? gps ? vehicle location systems ? wireless lans l and g rid a rray advantages ? inherent low profile ? excellent solderability ? low parasitics ? better heat dissipation top view frequency port ins. return loss power jc operating (ghz) impedance loss (db min) (watts) (oc /watts) temperature (ohms) (db max) (oc) dc -2.5 50 0.05 20 30 140 -55 to +85 2.5 C 4.0 50 0.10 20 19 140 -55 to +85 4.0 C 6.0 50 0.15 15 9 140 -55 to +85 * specification based on performance of component assembled properly on printed circuit board with 50 nominal impedance. quality inspection finished parts are 100% tested for electrical parameters and visual characteristics. termination nisn compatible with automatic soldering technologies: pb free reflow, wave soldering, vapor phase and manual. operating temperature - 55oc to +85oc x2a series 2020 size t packaging t = 1000pcs t&r t/250 = 250pcs t&r b = bulk how to order rfdc type
mlo tm rf-dc smt crossover 2 rf in/out gnd gnd rf in/out 0.76 0.10 x4 (0.030 0.004 x4) 0.99 0.20 x4 sq (0.039 0.008 x4 sq) top bottom 4.98 0.25 (0.196 0.010) gnd gnd gnd gnd gnd 4.98 0.25 (0.196 0.010) rf in/out rf in/out 1.12 0.10 (0.044 0.004) 0.40 0.04 (0.016 0.002) gnd 0.74 0.10 x4 (0.029 0.004 x4) side 0.40 0.04 (0.016 0.002) x4) mechanical outline
0.0 -0.1 -0.2 -0.3 -0.4 -0.5 insertion loss (db) frequency (ghz) 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 rf/dc crossover ?insertion loss rf/dc crossover ? insertion loss 3 mlo tm rf-dc smt crossover rf-dc smt crossover performance: 0.3 ghz to 6 ghz mounting procedure mounting footprint mlo tm smt crossovers require 50 transmission lines leading to and from all of the rf ports. proper grounding is required in order to ensure optimal device performance. if these conditions are not met then performance parameters including insertion loss, return loss and any isolation may not meet published values. all of the mlo tm components utilize castellated interconnects which allow for high yield assembly, expansion matched and halogen free dielectric. when mounting the user must be mindful of the following: a) ensure the rf pads of the device are in contact with the circuit trace of the printed circuit board and b) the ground plane of neither the component nor the pcb is in contact with the rf signal. parts are specifically oriented in the tape and reel. to ensure proper electrical and thermal performance there must be a ground plane with 100% solder connection underneath the part. -10- -20 -30 -40 -50 -60 return loss (db) frequency (ghz) 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 rf/dc crossover ?return loss rf/dc crossover ? return loss 1.60 sq typ (0.063) 50 transmission line multiple plated thru holes to ground dc line 0.86 typ (0.034) 3.75 (0.148) dimensions are in mm (inches)
mlo tm rf-dc smt crossover automated smt assembly the following section describes the guidelines for automated smt assembly of mlo tm rf devices which are typically land grid array (lga) packages or side termination smt packages. control of solder and solder paste volume is critical for surface mount assembly of mlo tm rf devices onto the pcb. stencil thickness and aperture openings should be adjusted according to the optimal solder volume. the following are general recommendations for smt mounting of mlo tm devices onto the pcb. smt reflow profile common ir or convection reflow smt processes shall be used for the assembly. standard smt reflow profiles, for eutectic and pb free solders, can be used to surface mount the mlo tm devices onto the pcb. in all cases, a temperature gradient of 3c/sec, or less, should be maintained to prevent warpage of the package and to ensure that all joints reflow properly. additional soak time and slower preheating time may be required to improve the out-gassing of solder paste. in addition, the reflow profile depends on the pcb density and the type of solder paste used. standard no-clean solder paste is generally recommended. if another type of flux is used, complete removal of flux residual may be necessary. example of a typical lead free reflow profile is shown below: profile parameter pb free, convection, ir/convection ramp-up rate (tsmax to tp) 3oc/second max. preheat temperature (ts min to ts max) 150oc to 200oc preheat time (ts) 60 C 180 seconds time above t l , 217oc (t l ) 60 C 120 seconds peak temperature (tp) 260c time within 5oc of peak temperature (tp) 10 C 20 seconds ramp-down rate 4oc/second max. time 25oc to peak temperature 6 minutes max. critical zone t l to tp ramp-down ramp-up ts max 25 t 25? to peak ts min ts preheat tp tp t l t l time temperature 4
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