====== Pmod OC1 Reference Manual ======
The Digilent Pmod OC1 (Revision C) uses open-collector BJTs to drive high current applications.

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== Download This Reference Manual == 
  * {{:reference:pmod:pmodoc1:pmodoc1_rm.pdf| PDF}}

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===== Features =====
  * Four 100mA (200mA max) transistors
  * Four output clamp diodes 
  * 40V voltage threshold 
  * 6-pin Pmod port with %%GPIO%% interface


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=====Functional Description =====
The %%Pmod OC1%% utilizes [[http://www.nxp.com/documents/data_sheet/MMBT3904.pdf|MMBT3904 transistors]] in an open collector format. Each transistor can drive up to 100 mA of current individually and can draw up to 200 mA of current. 

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===== Interfacing with the Pmod=====
The %%Pmod%% communicates with the host board via the [[pmod:communication_protocols:gpio|GPIO protocol]]. A logic level high voltage will "turn on" the BJT and a logic low signal will keep the BJT "off". 


==== Pinout Description Table ====
^  Pin  ^  Signal  ^  Description          ^
|  1    |  P1      |  Output 1             |
|  2    |  P2      |  Output 2             |
|  3    |  P3      |  Output 3             |
|  4    |  P4      |  Output 4             |
|  5    |  GND     |  Power Supply Ground  |
|  6    |  VCC     |  Positive Power Supply  |

Any external power applied to the %%Pmod OC1%% must be within 2.7V and 5.25V; however, it is recommended that Pmod is operated at 3.3V.

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===== Physical Dimensions =====
The pins on the pin header are spaced 100 mil apart. The PCB is 1 inch long on the sides parallel to the pins on the pin header and 0.8 inches long on the sides perpendicular to the pin header.

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===== Additional Information =====
The schematics of the %%Pmod OC1%% are available {{reference:pmod:pmodoc1:pmodoc1_sch.pdf|here}}. Additional information about the BJTs including specific timings of the chip can be found by checking out its datasheet [[http://www.nxp.com/documents/data_sheet/MMBT3904.pdf|here]]. 

Example code demonstrating how to get information from the %%Pmod OC1%% can be found [[pmod:pmodoc1:start#example_projects|here]]. 

If you have any questions or comments about the %%Pmod OC1%%, feel free to post them under the appropriate section ("Add-on Boards") of the [[https://forum.digilent.com/|Digilent Forum]].