20-151-0178 Rabbit Semiconductor, 20-151-0178 Datasheet - Page 66

• Manufacturer Part Number: 20-151-0178
• Description: CABLE CONVERTER RS-232 TO USB
• Manufacturer: Rabbit Semiconductor

Specifications of 20-151-0178

• Accessory Type: USB to RS232 Adapter
• Product: Microcontroller Accessories
• For Use With/related Products: Rabbit-based Boards
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 20-151-0178; 316-1181

Figure 5.2 Water Tower Analogy of Sinking and Sourcing Power
5.4.2 Line Drivers
Line drivers are used to increase current, thereby enhancing transmission reliability.
5.4.3 Protection Diodes
A protection diode gives a path for high voltages to follow when driving an inductive load. Just as you
cannot stop a freight train instantaneously, you cannot stop current in a magnetic coil instantaneously.
When the transistor is turned on, current runs through the transistor, then through the coil. The diode has
no current running through it at all because it is back biased (current only runs in the direction of the diode
arrow.) For a very short time immediately after the transistor turns off, current is still moving through the
coil. It must go somewhere. The protection diode provides a path for that current to go around in a loop
until the coil’s resistance eventually stops the current (typically takes less than 5 ms). A very high voltage
would develop at the transistor’s collector without the protection diode, which could zap and destroy the
transistor. Typical inductive loades include the magnetic coils in relays, soleniods and electric motors.
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