User manual

MTD6505 3-Phase BLDC Sensorless Fan Controller Demo Board User’s Guide
DS52009A-page 14 © 2011 Microchip Technology Inc.
2.2.1.1 CONTROL/MONITORING
The Control/Monitoring Group box contains two buttons:
• Turn On/Off VDD button enables/disables the power supply on the V
DD
pin of the
MTD6505 device.
• Change Direction is used to inverse the sense of the fan rotation. The Change
Direction button is available only when V
DD
is turned off.
2.2.1.2 R
PROG
PIN
The R
PROG
Pin Group box allows the selection of the desired R
PROG
resistor value.
This value depends on the K
M
(mV/Hz) of the fan. See the section Section 2.3 “How
to define the correct R
PROG
Value” for more information on the R
PROG
selection.
One particular mode, HighZ, allows the setting of an external R
PROG
resistor value
directly on the plug-in module.
In order to use the MTD6502B with the MTD6505 3-Phase BLDC Sensorless Fan Con-
troller Demo Board, use K
M
= 0.
2.2.1.3 CHART
This part of the GUI displays a chart of the MTD6505 current consumption (mA) on the
V
DD
pin, and the fan speed (Revolutions Per Minute - RPM) by measuring the FG fre-
quency. The chart adds 10 values per second. The three buttons have the following
functions:
• Start/Stop – allows the values acquisition to start or stop
• Clear – removes all the values added to the chart
• Auto Scale – allows the restoration of the default scaling. In the default scaling
mode, the chart will automatically adjust the scaling to ensure the complete view
of the whole added values. In addition, when selecting a part of the chart with the
mouse, it is possible to zoom in the selection. The mouse wheel zoom in/out is
also enabled.
2.2.1.4 PWM PIN
The PWM Group box provides a slide bar to set the PWM ratio on the MTD6505 PWM
pin. The gauge below indicates the current PWM applied.
2.2.1.5 V
DD
PIN
The V
DD
Group box also provides a slide bar to set the desired V
DD
value. The gauge
below indicates the instant V
DD
value measured by the MTD6505 3-Phase BLDC
Sensorless Fan Controller Demonstration Board.
2.2.1.6 CURRENT/SPEED FIELDS
Current field shows the instant current measure (mA). Speed field shows the instant
speed measure (RPM).