I asked PcbWay to produce this small pcb series for use of optical fiber POF duplex cables with HFBR-1523Z / 2523Z series transmitters and receivers at 40kbps, for my automation / remote control loop project at a maximum distance of 100m.

No restrictions on being able to adopt compatible Versatile Link HFBR-x5xxZ tx / rx also for other higher speed kbps / Mbps devices based on Avago technical documentation (now Broadcom).

SN75451BP DIP-8 driver on Machined Tin Plated socket and electrolytic capacitor such as through hole assembly, for practical reasons in case of future replacement and repairs, while remaining resistor and capacitor components are all in SMD.

The component marked FB is a smd ferrite in series between the connector and the entire + 5VDC module power supply.

On the opposite side of the pcb module of the opto tx / rx devices, I adopted 2x5 90 ° IDC male connectors, with the choice of connecting with a short flat cable IDC connectors headed to another pcb MCU, or on an intermediate pcb backplane for multiple management of these opto modules with direct 2x5 vertical or 90 ° IDC female pcb to MCU by mechanical guide supports.

The connector arrangement of power pins and TTL tx / rx signals follows the PORT'x strip 2x5 connection layout adopted on Mikroe development boards.

In this pcb I had foreseen the presence of two 3mm led through hole, one red and one green 5V direct integrated resistor for monitor presence of tx and rx activity (ex. Kingbright L-7104ID-5V & L-7104GD-5V), idea then abandoned .

The assembly of the red LED on the tx part is however perfectly functional as shown in the example photo.

The green led, due to project error distances and dimensions is still possible but slightly hindered by the plastic protruding tooth HFBR-2523Z.

Again, from another circuit design error, the green led driving from the unused section SN75451 via "0 RX" ohm jumper will only work with a trick, by soldering between 2 edge pads zero ohm base pin and collector pin towards anode green led by a PNP digital transistor BCR162 or equivalent, and applying to the emitter pin the + 5V taken from the + 4.7uF ring pad soldering via another zero ohm smd jumper or wire jumper (*).

Some remaining smd pads connected to the tx or rx circuits for other capacitors or resistors are not used, as they are free inserted for experimental purposes only.

Bill of materials:

W194356ASH4 PCB

1 HFBR-1523z or HFBR-15xxZ tx series

1 HFBR-2523z or HFBR-25xxZ rx series

1 SN75451BP DIP or equivalent driver

2 res 1k SMD 1206

1 res 3.3k SMD 1206

1 res 47..50 ohm SMD 1206 1 / 2W

1 cond 4.7uF 16V..25V

1 cond 100nF SMD 1206

1 cond 100pF SMD 1206

1 ferrite bead SMD 1206 (ex. Wurth 74279215 or other)

1 IDC male 2x5 2.54 90 °

1 DIP-8 socket turned

+ for led tx / rx mods option:

1 Kingbright L-7104ID-5V

1 Kingbright L-7104GD-5V

1 BCR162 digital PNP or eq. SOT-23

2 res 0 ohm SMD 1206 jumper (as 1 for 5v emitter pin jumper (*))

1 res 1k SMD 1206