Digilent PmodOC1TM Open Collector Output Module Board Reference Manual (R) www.digilentinc.com Revision: 04/12/05 215 E Main Suite D | Pullman, WA 99163 (509) 334 6306 Voice and Fax Overview The Digilent PmodOC1 Open Collector Output Module Board (the OC1TM) can drive high current devices using MMBT3904 output transistors. The transistors are driven by logic signals from a Digilent system board. * * * * * four 100mA (200mA max) MMBT3904 transistors a 6-pin header and 6-pin connector four output clamp diodes 40V voltage threshold small form factor (0.75" x 0.80"). Functional Description Each transistor functions independently of the others, so they can be used individually or simultaneously. Each transistor has a collector that conducts current between an outside device and a ground connection established by the OC1. When a transistor is turned on, current flows through the circuit connected to the corresponding pin on J2. J1 Connector Features include: P1 P1 P2 P2 P3 P3 P4 P4 J2 Connector The transistors function as switches and can drive relays and turn on LEDs, motors, and other outside devices. GND Vcc OC1 Circuit Diagram The OC1 has four output clamp diodes that prevent damage to the transistors by dissipating fly-back current from inductive loads. system boards, like the Digilent Pegasus board, have a 6-pin header that can connect to the module with a 6-pin cable. To connect the OC1 to other Digilent system boards, a Digilent Modular Interface Board (MIB) and a 6-pin cable may be needed. The MIB plugs into the system board, and the cable connects the MIB to the OC1.The OC1 also has a 6-pin connector for easy connection to the Digilent Pmod connector module. The OC1 has a 6-pin header for easy connection to a Digilent system board. Some For more information, see the reference manual at www.digilentinc.com. Doc: 502-062 page 1 of 1 Copyright Digilent, Inc. All rights reserved. Other product and company names mentioned may be trademarks of their respective owners. Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Digilent: 410-062P