Renard8
First PCB Revision
This board can be distinguished by the letters XA on the solder side of the board, and by not having any silkscreen or soldermask.
Schematic
This schematic is intended to exactly represent the first revision of the PCB.
Revision XA PCB Errata
The board has three known issues that will be changed on the next revision of the PCB (if there is one).
1) The order of the outputs on J4, J5 is exactly reversed from that of the Renard16, Renard64 and other Renard boards. Output 1 appears on the connector (J5, pin 8) where Output 8 would be expected (based on the other boards) instead of the expected location (J4, pin 2), and so forth. The power and ground connections are in the proper and expected location on these connectors.
2) The RS232/RS485 connections on pins 4,5 of J1 and J2 are transposed with respect to the other boards.
3) The input biasing resistors (R5, R6) are connected wrong, so that they force the serial input on the PIC to go low when the input cable to the board is disconnected. This does not appear to cause any problems at the time.
PCB Image
The blue layer is the solder side, and the red layer represents the component side. The silkscreen layer is shown on this composite image to indicate where the various components are located. None of the boards manufactured to date actually include the silkscreen or soldermask layers.
BOM
Note: this BOM is slightly different from the previously published versions. The preferred part for diode D3 is now a BAT42 diode, because it has lower forward voltage drop and will fit in the holes on the board better. The old parts can continue to be used on previously assembled and working boards. In addition, the regulator is now specified as a LP2950, although you may substitute a LM79L05 if the input voltage to the board is high enough.
The part numbers in this BOM take precedence over those in the schematic above.
PCB 1 TBA Renard8 PCB Resistors 3 299-27K-RC 27K Resistor, 1/4 W, Axial R5, R6, R8 2 299-1K-RC 1K Resistor, 1/4 W, Axial R3, R4 1 660-MF1/4DCT52R1200F 120 Resistor, 1/4 W, Axial R1 1 299-330-RC 330 Resistor, 1/4 W, Axial R7 1 299-10K-RC 10K Resistor, 1/4 W, Axial R2 Capacitors 1 80-C322C104K5R 0.1 uF Radial-lead Ceramic Capacitor C2 1 140-XRL16V1000-RC 1000 uF, 16V Electrolytic Capacitor C1 Diodes 1 78-1N5229B 4.3v 0.5w Zener D2 1 78-1N5239B 9.1v 0.5w Zener D1 1 625-BAT42 30V 100mA Schottky Diode (preferred) D3 or 1 625-1N5819-E3 50V 1A Schottky Diode (not preferred) D3 or 1 625-1N4001-E3 50v 1A Diode (not preferred) D3 or 1 625-1N4148-E3 50V, 100 mA Diode (not preferred) D3 1 604-WP7104GT T1 Green LED D4 Transistors 1 512-2N3904TA Small Signal Transistor Q1 Connectors 4 571-5202514 AMP Modular Jacks, Right Angle J1, J2, J4, J5 or 4 571-5564161 AMP Modular Jacks, Top Entry or 4 538-95003-2881 Molex Modular Jacks, Vertical PCB mount 1 575-199314 14 Pin Low Profile IC Socket XU3 ICs 1 595-SN65LBC179PE4 RS485 Receiver/Transmitter 65LBC179 U1 1 579-PIC16F688-I/P PIC16F688, unprogrammed, DIP14, Industrial Temp U3 1 --- Regulator, 5V, Low Power LP2950ACZ-5.0 U2
There isn't a mouser part number specified for the regulator because they are only available in large quantities. It is available from other sources, and there are other regulators available that should work.
BOM Revision History
7/21/2007 PJS Changed regulator
Second Revision
TBA