CY8C42323/CY8C42423
PRELIMINARY
CY8C42123/CY8C42223
Document 38-12034 Rev. *C
Page 7 of 42
5.3
Brushless DC Fan Motor
The CY8C42x23 PSoC can be configured as a one- or two-phase brushless DC motor controller suitable for use in small brushless
fans. In this configuration, the HVdd voltage is high enough to drive a one- or two-phase brushless motor coil, typically 12V. The
HVdd voltage is converted to 5V by the internal Low Drop-Out Regulator for use by the Power PSoC Core. Additionally, several
milliamperes of 5V from the internal regulator is made available to bias a hall sensor and thermistor. The high side PFETs of the
H-bridge are driven by the GDO0 and GDO1 pins controlled by the processor. The low side NFETs of the H-bridge are driven by
the HVO[0] and HVO[1] pins controlled by a combination of the processor and the pulse width modulator (PWM) for speed control.
A differential comparator is used to determine rotor position from either an analog or digital hall sensor to facilitate rotor commu-
tation. A second comparator and 8-bit DAC, VDAC0, are available to provide an optional hardware current limit. The 10-bit ADC
is available to measure optional parameters such as ambient temperature or motor coil current. The M8C processor handles coil
commutation, user customizable speed, and control algorithms as well as an optional communications interface. The PSoC digital
resources provide an 8-bit PWM output to drive the motor coil as well as two timer configurations. Using dynamic reconfiguration,
two digital blocks are used to create a 16-bit timer to measure the tachometer period while the same two blocks are also used to
create two 8-bit timers to measure the input PWM duty cycle.
5.3.1
Resources
This application leaves 3 GPIO pins, 1 digital block, I2C and ample memory unused for further application customization.
Figure 5-3. Brushless DC Fan Motor
PWM DB
GDO1
ATTEN0
ATTEN1
AMuxBus0
AMuxBus1
AMuxBus2
AMuxBus3
P0[6]
P0[4]
P0[2]
P0[0]
P1[0]
P0[7]
P0[5]
P0[3]
`
P1[1]
ODAC0
ODAC1
VDAC0
ODAC0
VBG
IBIAS
VDAC0
VDAC1
ODAC1
VDAC1
VS1,HVO[1]
GDO0
VS0,HVO[0]
DBC01
DBC00
IDAC0
COMP1
COMP0
Analogto
Digital
Convertor
IDAC1
Kill
HVdd
InternalVdd
ANALOG and HIGH VOLTAGE
SECTIONS
LowDrop-Out
Regulator
HVdd
R
ISENSE
HVdd
Analog
Hall
Sensor
5V
P0[1]
5V
T
16-bit Timer (Tachometer)
2x8-bit Timer (Input PWM)
PWMOut
Capture
InputPWM
TachOut
Optional
Optional
5V Out
DIGITAL SECTION
1 or 2 Phase
Brushless
Motor
(1 Phase
Depicted)
HVDriver
HVDriver