MLOTM RF-DC SMT Crossover
GENERAL DESCRIPTION
The MLOTM 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. MLOTM crossovers have been subjected
to JEDEC reliability standards and 100% electrically tested. The RF-DC crossovers
are available in NiSn.
FEATURES
• DC – 6.0 GHz
• RF – DC Crossover
• Low Loss
• DC Isolation
• Surface Mountable
• Tape and Reel
• 100% Tested
APPLICATIONS
• Mobile communications
• GPS
• Vehicle location systems
• Wireless LAN’s
LAND GRID ARRAY
ADVANTAGES
• Inherent Low Profile
• Excellent Solderability
• Low Parasitics
• Better Heat Dissipation
TOP VIEW
Frequency Port Ins. Return Loss Power
θ
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 – 4.0 50 0.10 20 19 140 -55 to +85
4.0 – 6.0 50 0.15 15 9 140 -55 to +85
* Specification based on performance of component assembled properly on printed circuit board with 50Ω 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
6
144
MLOTM RF-DC SMT Crossover
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
6
145
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
MLOTM RF-DC SMT Crossover
RF-DC SMT CROSSOVER PERFORMANCE: 0.3 GHZ TO 6 GHZ
MOUNTING PROCEDURE MOUNTING FOOTPRINT
MLOTM SMT crossovers require 50Ω
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 MLOTM 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)
6
146
MLOTM SMT Crossover
AUTOMATED SMT ASSEMBLY
The following section describes the guidelines for automated
SMT assembly of MLOTM 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 MLOTM 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 MLOTM
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 MLOTM devices onto the PCB. In all cases, a temperature
gradient of 3°C/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 – 180 seconds
Time above TL, 217ºC (tL) 60 – 120 seconds
Peak temperature (Tp) 260°C
Time within 5ºC of peak temperature (tp) 10 – 20 seconds
Ramp-down rate 4ºC/second max.
Time 25ºC to peak temperature 6 minutes max.
Critical Zone
TL to Tp
Ramp-down
Ramp-up
Ts max
25
t 25ºC to Peak
Ts min
ts
Preheat
Tp tp
TLtL
Time
Temperature
6
150
