Difference between pages "VGAX49" and "VGAX49 Assembly Sheet"

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[[File:VGAX49_P901-cropped-720px.jpg]]
+
[[File:VGAX49-BW.PNG]]
  
== Features ==
+
* Resistor values depend on drive current of the IC driving the pins (see [[VGAX49#Simulation|this page for details]])
  
* Digital VGA adapter
+
== 5:6:5 Parts List ==
* 16-bit digital video
 
** 5:6:5 (R:G:B) mapping (maximum)
 
** 2:2:2 (R:G:B) mapping (option)
 
* Uses summing resistors
 
* DB-15F connector
 
* 49x49mm ODAS form factor
 
* Mounting holes
 
  
== Connectors ==
+
{| class="wikitable"
 +
! Qty
 +
! Value
 +
! RefDes
 +
!
 +
! Qty
 +
! Value
 +
! RefDes
 +
|-
 +
| 3
 +
| 1K
 +
| R3,R8,R14
 +
|
 +
| 1
 +
| Conn, Rt ang, 2x10
 +
| J1
 +
|-
 +
| 3
 +
| 2.2K
 +
| R4,R9,R15
 +
|
 +
| 1
 +
| VGA
 +
| P1
 +
|-
 +
| 3
 +
| 270
 +
| R1,R6,R12
 +
|
 +
|
 +
|
 +
|
 +
|-
 +
| 3
 +
| 3.9K
 +
| R5,R10,R16
 +
|
 +
|
 +
|
 +
|
 +
|-
 +
| 3
 +
| 560
 +
| R2,R7,R13
 +
|
 +
|
 +
|
 +
|
 +
|-
 +
| 1
 +
| 8.2K
 +
| R11
 +
|
 +
|
 +
|
 +
|
 +
|-
 +
|}
  
[[File:VGAX49.PNG]]
+
== 2:2:2 Parts List ==
  
=== J1 - Digital Connections ===
+
{| class="wikitable"
 
+
! Qty
=== P1 - VGA connector ===
+
! Value
 
+
! RefDes
== Simulation ==
+
!
 
+
! Qty
=== 2:2:2 Resistor Simulation ===
+
! Value
 
+
! RefDes
* 3.3V Drive out of FPGA
+
|-
* 1V is drive level for VGA specification
+
| 3
* 8 mA max drive current
+
| 270
* VGA presents a 75 Ohm load
+
| R1,R6,R12
* Series resistors present a voltage divider between the resistors on the card and the VGA load
+
|
* 1V at 75 Ohms is 13.3 mA
+
| 1
* Each color is independently driven
+
| Conn, Rt ang, 2x10
* The resistor with the smallest resistance value has larger current from the FPGA pin
+
| J1
* Current switches from source to sink depending on the voltages on the other resistors
+
|-
* Use common value, 1% resistors
+
| 3
* 330 Ohm series resistor into a 75 Ohm load is 8.15 mA
+
| 560
** Voltage with 330/75 ohm voltage divider is 0.61V - not full brightness
+
| R2,R7,R13
 
+
|
=== 5:6:5 Resistor Simulation ===
+
| 1
 
+
| VGA
* 3.3V Drive out of FPGA
+
| P1
* 1V is drive level for VGA specification
+
|-
* 8 mA max drive current
+
|}
* VGA presents a 75 Ohm load
 
* Series resistors present a voltage divider between the resistors on the card and the VGA load
 
* 1V at 75 Ohms is 13.3 mA
 
* Each color is independently driven
 
* The resistor with the smallest resistance value has larger current from the FPGA pin
 
* Current switches from source to sink depending on the voltages on the other resistors
 
* Use common value, 1% resistors
 
* 330 Ohm series resistor into a 75 Ohm load is 8.15 mA
 
** Voltage with 330/75 ohm voltage divider is 0.61V - not full brightness
 
 
 
== Schematic ==
 
 
 
* [http://land-boards.com/VGAX49/VGAX49_Rev1_Schematic.pdf VGAX49 schematic]
 
 
 
== Assembly Sheet ==
 
 
 
* [[VGAX49 Assembly Sheet]]
 

Revision as of 18:10, 13 February 2020

VGAX49-BW.PNG

5:6:5 Parts List

Qty Value RefDes Qty Value RefDes
3 1K R3,R8,R14 1 Conn, Rt ang, 2x10 J1
3 2.2K R4,R9,R15 1 VGA P1
3 270 R1,R6,R12
3 3.9K R5,R10,R16
3 560 R2,R7,R13
1 8.2K R11

2:2:2 Parts List

Qty Value RefDes Qty Value RefDes
3 270 R1,R6,R12 1 Conn, Rt ang, 2x10 J1
3 560 R2,R7,R13 1 VGA P1