omc506 International Rectifier Corp., omc506 Datasheet - Page 5

• Manufacturer Part Number: omc506
• Description: Closed Loop Speed Controller For 3-phase Brushless Dc Motor Mp-3t Package
• Manufacturer: International Rectifier Corp.

The OMC506 has been designed with an internal over temperature protection circuit. The circuit provides a
diagnostic in the event an over temperature condition occurs in the power stage. The circuit normally outputs
a voltage level < 0.5Vdc. When the power stage reaches 140°C, the V
OMC506 also outputs a control function for this circuitry. A logic “0” at pin 18 will disable the over temperature
circuit and a logic “1” will force V
with a system controller. The system controller can act on the pretense of an over temperature and shut the
OMC506 down. The system controller may opt to over ride the over temperature flag and disable the circuit
over temperature circuitry. In addition, the system controller can force the V
(BIT) feature at the system level. The over temperature circuitry will reset when the power stage has cooled to
130°C. Finally, an internal diode can be jumpered causing the temperature circuitry to latch on trip, requiring
a power off reset.
Current Limit
The OMC506 provides outputs from the internal current sense resistor (pin 7& 8). These outputs can be
directly wired to the C.S. +, C.S.- (pin 28 & 27) inputs. The outputs can also be used in external current limit
circuitry. Figure 1 shows a typical connection of the OMC506’s current limit circuitry.
Figure 1 - Current Limit Circuitry
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Over Temperature Protection
OUT
to go high. The over temperature circuitry has been designed to interface
OUT
(pin19) will rise to +15Vdc. The
OUT
high as part of a built in test
OMC506
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