Schematic Design Tips -1
Based on my experience here I'm sharing some points to do error free hardware schematic design.
1.While creating schematic symbol and Footprint give easy and consistence naming.
For Example
2.Don't ever make four cross wire junction in your schematic.
For schematic review most of the time we will send schematic PDF only. Four cross wire junction is very difficult to make ensure all the four wires are connected properly at that junction. If we miss it will leads to one more PCB revision.
While selecting connectors (Specially optical connectors) we should have at least 2 alternate part numbers.This alternate components save our life when actual part goes obsolete.
4. Use consistence symbols and text placement.
Proper text alignment in schematic will be easy while reviewing the schematic.
If schematic has proper text alignment, you don't need to rotate your head left and right while reviewing the schematic and this will avoid unwanted headache 😀
5. While doing schematic maintain the same sheet size. This will be very help full while taking printout. Better don't go beyond A3 paper size.
6. If you are going to add any new block in your schematic design refer Eval PCB.
Before adding any new IC's in your design check the reference design or Eval board schematic for that particular chip. That chip might need some special care in power supply section or other thermal aspects.
7. While using connectors add placement note.
Most of the times connectors need to be placed in board edge. Some connectors needs more mechanical care.
8. Properly mention the differential pair line and 50 Ohm single ended line in schematic.
9. If not really needed don't unnecessary use too many different value resistors and capacitors. This will simply add too many line items in design.
If you are using 1.1k resistor value for Linear regulator feedback network that is reasonable. If you are use 1.1k for LED current limiting purpose then that is not good idea. Similarly most of the times we will use 0.1uf with different voltage rating, that can be avoided.
10. Based on the design requirement select the proper component
Example:
For automotive designs all components should be AEC qualified. For RF section you might need COG/NPO capacitors.
1.While creating schematic symbol and Footprint give easy and consistence naming.
For Example
- Diode and LED - pin name as A, K
- For Transistors C,B,E
- MOSFET G,D, S
- IF IC's has more Ground pins, Provide GND1, GDN2 ... GNDn.
- For thermal ground pads TGND
In my early stage, I used to give the name as 1 and 2 for Diode symbol, while matching the Footprint it made chaos.
2.Don't ever make four cross wire junction in your schematic.
For schematic review most of the time we will send schematic PDF only. Four cross wire junction is very difficult to make ensure all the four wires are connected properly at that junction. If we miss it will leads to one more PCB revision.
3.While selecting components at-least select 2 alternate part numbers.
While selecting connectors (Specially optical connectors) we should have at least 2 alternate part numbers.This alternate components save our life when actual part goes obsolete.
4. Use consistence symbols and text placement.
Proper text alignment in schematic will be easy while reviewing the schematic.
If schematic has proper text alignment, you don't need to rotate your head left and right while reviewing the schematic and this will avoid unwanted headache 😀
5. While doing schematic maintain the same sheet size. This will be very help full while taking printout. Better don't go beyond A3 paper size.
6. If you are going to add any new block in your schematic design refer Eval PCB.
Before adding any new IC's in your design check the reference design or Eval board schematic for that particular chip. That chip might need some special care in power supply section or other thermal aspects.
7. While using connectors add placement note.
Most of the times connectors need to be placed in board edge. Some connectors needs more mechanical care.
8. Properly mention the differential pair line and 50 Ohm single ended line in schematic.
9. If not really needed don't unnecessary use too many different value resistors and capacitors. This will simply add too many line items in design.
If you are using 1.1k resistor value for Linear regulator feedback network that is reasonable. If you are use 1.1k for LED current limiting purpose then that is not good idea. Similarly most of the times we will use 0.1uf with different voltage rating, that can be avoided.
10. Based on the design requirement select the proper component
Example:
For automotive designs all components should be AEC qualified. For RF section you might need COG/NPO capacitors.
