Microchip Technology MCP19117, Руководство пользователя

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MCP19117 Flyback Stand-Alone Evaluation Board User’s Guide
DS50002472A-page 24
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2016 Microchip Technology Inc.
3.2.1.3 PARAMETERS SECTION
This section controls the Switching Frequency, Maximum Duty Cycle, Output Current
and Current Sense Resistor parameters, as shown in
Figure 3-4
FIGURE 3-4: Parameters Options
The switching frequency is user programmable in Fixed Frequency mode over the
range of 60 kHz to 1 MHz. Switching Frequency can be adjusted in 10 kHz intervals.
The maximum duty cycle is programmable from 0 to 100%.
The Output Current can be adjusted within a range of 0 to 500 mA. The Current Sense
Resistor (R6) value on the MCP19117 Flyback Stand-Alone Evaluation Board is
200 m

. Both of these values are used to calculate the set point value written to the
VREFCON register. Do NOT raise the resistor value in the GUI without changing the
resistor on the evaluation board to match. Failure to do so could result in damage to
the evaluation board.
CAUTION
Increasing switching frequency results in increased switching losses in the MOSFETs.
It is the user's responsibility to ensure that the MOSFETs are operated within their safe
operating range.
Note: Attempting to write a value larger than 0xFF to VREFCON is prohibited by
the GUI.