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. As such, 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.
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 D3 or (not preferred) 1 625-1N5819-E3 50V 1A Schottky Diode D3 or (not preferred) 1 625-1N4001-E3 50v 1A Diode 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 1 595-UA78L05ACLPRE3 Regulator, 5V U2
If you can obtain it, a LP2950-5.0 regulator is preferred for U2 in place of the 78L05, because it has a lower dropout voltage and lower quiescent current.
Second Revision
TBA