MTD6505 MICROCHIP [Microchip Technology], MTD6505 Datasheet - Page 10

• Manufacturer Part Number: MTD6505
• Description: Sinusoidal Sensorless 3-Phase Brushless DC Fan Motor Driver
• Manufacturer: MICROCHIP [Microchip Technology]

MTD6505
4.7
V
supply internal logical blocks. The V
connect an external decoupling capacitor (1 µF or
higher). Notice that this pin is for IC internal use, and is
not designed to supply DC current to external blocks.
4.8
Km is the electro-mechanical coupling coefficient of the
motor (also referred to as “motor constant” or “BEMF
constant”). Depending on the conventions in use, the
exact definition of Km and its measurement criteria can
vary among motor manufacturers. To accommodate
various motor applications, the MTD6505 provides
options to facilitate diverse BEMF coefficients.
The MTD6505 defines BEMF coefficient (Km) as the
peak value of the phase-to-phase BEMF voltage,
normalized to the electrical speed of the motor. The
following table offers methods to set the Km value for
the MTD6505 device.
TABLE 4-2:
The R
trolled by the firmware. For any given R
nal control block will output the corresponding Km
range.
DS22281A-page 10
BIAS
Option
Km0
Km1
Km2
Km3
Km
PROG
voltage is generated internally and is used to
Internal Voltage Regulator
BEMF Coefficient Setting
sensing is actually a sequence that is con-
Km (mV/Hz) Range
3.25
Min
Km SETTINGS
6.5
13
26
Phase-to-Phase
Max
6.5
13
26
52
BIAS
PROG
pin is used to
, the inter-
R
3.9 k
24 k
V
GND
PROG
BIAS
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