Thursday, December 17, 2020
Wednesday, December 16, 2020
RF Design Reuse - Stackup Comments
For RF design reuse the 50 ohm trace width, distance to RF reference plane and PCB material need to be tightly constrained.
A well designed RF circuit can be moved to another PCB stackup provided the RF trace widths and dielectric thickness to the RF reference plane are nearly the same.
RF matching work will be needed to optimize RF performance after changing stackups.
The Dielectric Constant (Dk or Er) is determined by the ratio of resin to glass.
The Dk of the material and distance to the reference plane determines the trace widths of the controlled impedances.
Dissipation Factor (Df or loss tangent). Low Df materials are preferred for RF performance.
Layer stackup considerations may include high-speed traces on outer layers which will require a thinner dielectric (~2.5mil) between L1 to L2. A thicker dielectric (~3mil) can be used with a few impedance discontinuities and imperfections, i.e. trace width neck downs on the outer layers.
Vias in Pad Plated Over (VIPPO). RF designers appreciate VIPPO because it reduces the parasitics associated with vias and traces connected to RF components.
For fine pitch components in the design use thru-hole vias with a minimum size of 0.2mm / 0.45mm (drill / pads) or 8/18mil and very sparingly use 0.2mm / 0.4mm (8/16) where needed.
Use 10/22mil vias where possible. Vias hole sizes should be 15mil or smaller to accommodate non-conductive fill and plated over vias ( VIPPO).
For high-speed designs consider using blind vias or back drilling a few thru-hole vias to reduce stub lengths.
Blind vias may be less likely than thru-hole vias to experience via barrel fractures from repetitive thermal expansion in the Z axis, Blind vias can also be useful where RF isolation is needed.
That it !
Thursday, December 3, 2020
LOCTITE STYCAST PC 40-UMF
Conformal coating is specifically formulated to rapidly gel and immobilize when exposed to UV light and then fully cure when exposed to atmospheric moisture, ensuring optimum performance even in shadowed areas. LOCTITE STYCAST PC 40-UMF conforms to IPC-CC-830 requirements.
Friday, November 6, 2020
Sunday, October 25, 2020
Isola Core and Prepreg Data
Isola 370HR Core and Prepreg Data
www.isola-group.com › 370HR__Dk_Df_TablesFR408HR Core and Prepreg Data
www.isola-group.com › FR408HR__Dk_Df_TablesThat's it !
Thursday, October 15, 2020
Nine Dots Connect - Services
Nine Dots Connect offers PCB Layout and Librarian Services.
Nine Dots Connect offers Training and Setup for Concord Pro.
That's it !
Tuesday, October 13, 2020
Thursday, October 8, 2020
Capacitors - Epoxy Mount only Automotive Grade
Something to be aware of when selecting capacitors ?
https://www.digikey.com/products/en?keywords=CGA2B3X7R1H104K050BBclick on image to view
MLCC Automotive grade CGA series - May 2019 Datasheet states . . .
Conductive epoxy application CGA series, automotive grade of TDK's multilayer ceramic chip capacitor, is a product for conductive glue mounting, not for solder mounting. The risk of silver migration is reduced due to AgPdCu termination. The maximum operating temperature is 150°C and the capacitance range is up to 10µF.
That's It !
Thursday, September 24, 2020
Saturday, July 11, 2020
Surviving the App Note Challenge - Design 007 (June 2020)
Design007 Magazine, June 2020
Hartley: I loved Lee Hill’s comment that he
made years ago. “When I’m doing a review of
a circuit with a problem, if I see more than one
ground, I know there’s money to be made.”
Gotta love that !
Hartley: I loved Lee Hill’s comment that he
made years ago. “When I’m doing a review of
a circuit with a problem, if I see more than one
ground, I know there’s money to be made.”
Gotta love that !
Monday, June 8, 2020
Stackup Request - Designer to Customer
We need to work with your preferred fabricator to create formal stackups.
Please provide a email contact for your preferred fabricator. We can work with your fabricator to design formal stackups and keep you in the loop (on the email threads).
The overall board thickness, choice of materials (glass and resin) and the material Dk (dielectric constant) will determine precise trace widths and spaces for controlled impedance.
The ideal material for high-speed designs will have low a Df (dissipation factor) to minimize signal attenuation. The length of the traces should be considered when selecting the materials. If traces are short and wide then Df will not be a significant factor. Low Df material is typically used on a high speed back planes and RF designs. Note low Df materials are more expensive.
To maintain manufacturable trace widths as layer count increases where overall board thickness is ~80 mils or less the Dk needs to be lower than what is typically found on popular FR4 materials like 370HR. FR408HR and GETEK are a popular choices for low Dk materials.
Fabricators prefer plated holes (vias) sized with 10:1 or less aspect ratio. Where the aspect ratio is the overall board thickness divided by the drill hole size.
Note drill/pad sizes 8/20mil (0.2/0.5mm) are needed to allow for routing diff pairs or two signal traces between the vias under 1mm pitch BGA and routing one trace between the vias 0.8mm pitch connectors.
That's it !
Saturday, May 30, 2020
Electrical Calculators
Online Electrical Calculators - RapidTables
- Amps to kW calculator
- Amps to kVA calculator
- Amps to VA calculator
- Amps to volts calculator
- Amps to watts calculator
- Electricity bill calculator
- Energy consumption calculator
- Energy cost calculator
- eV to volts calculator
- Joules to watts calculator
- Joules to volts calculator
- kVA to amps calculator
- kVA to watts calculator
- kVA to kW calculator
- kVA to VA calculator
- kW to amps calculator
- kW to volts calculator
- kW to kWh calculator
- kW to VA calculator
- kW to kVA calculator
- kWh to kW calculator
- kWh to watts calculator
- mAh to Wh calculator
- Ohm's Law calculator
- Power calculator
- Power factor calculator
- VA to amps calculator
- VA to watts calculator
- VA to kW calculator
- VA to kVA calculator
- Voltage divider calculator
- Voltage drop calculator
- Volts to amps calculator
- Volts to watts calculator
- Volts to kW calculator
- Volts to joules calculator
- Volts to eV calculator
- Watts-volts-amps-ohms calculator
- Watts to amps calculator
- Watts to joules calculator
- Watts to kWh calculator
- Watts to volts calculator
- Watts to VA calculator
- Watts to kVA calculator
- Wh to mAh calculator
- Wire gauge calculator
Monday, May 11, 2020
Controlled Volume NPI - TTM
TTM is one of my favorite fabricators. TTM has great customer service and excellent stackup designers. Advanced and Engineering Capabilities.
So what is "Controlled Volume NPI" ?
This just a another buzzword for cutting edge (advanced) capabilities.
Example Controlled Volume NPI Design Technology:
Drill / Pad = 8 / 16mil (0.2 / 0.4mm) Thru-Hole Vias with VIPPO
Trace / Space = 3 / 3.25mil
As the title implies this is not high volume production. It is for low volume specialty designs which require special handling by a highly experienced fabricator with advanced capabilities.
And it's going to be a bit more expensive $$$
That's It !
So what is "Controlled Volume NPI" ?
This just a another buzzword for cutting edge (advanced) capabilities.
Example Controlled Volume NPI Design Technology:
Drill / Pad = 8 / 16mil (0.2 / 0.4mm) Thru-Hole Vias with VIPPO
Trace / Space = 3 / 3.25mil
As the title implies this is not high volume production. It is for low volume specialty designs which require special handling by a highly experienced fabricator with advanced capabilities.
And it's going to be a bit more expensive $$$
That's It !
Monday, May 4, 2020
10A 0402 Zero Ohm Resistor
For those times when you need a bigger zero ohm 0402 resistor :)
All zero ohm resistors are not equal and some maybe good fuses if your not careful.
KOA comes to the rescue. See KOA P/N TLRZ1ETTB
click on image to view.
That's it !
All zero ohm resistors are not equal and some maybe good fuses if your not careful.
KOA comes to the rescue. See KOA P/N TLRZ1ETTB
click on image to view.
That's it !
PCIE Express - AC Coupling Capacitors
click on image to view
Source: https://community.nxp.com/thread/463277
Other Refs:
xilinx - https://www.xilinx.com/support/answers/58921.html
Stack Exchange - Why Place Capacitors on PCIE Traces
That's it !
Source: https://community.nxp.com/thread/463277
Other Refs:
xilinx - https://www.xilinx.com/support/answers/58921.html
Stack Exchange - Why Place Capacitors on PCIE Traces
That's it !
Thursday, February 20, 2020
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