FCM8201 Fairchild Semiconductor, FCM8201 Datasheet - Page 14

• Manufacturer Part Number: FCM8201
• Description: FCM8201 is a three-phase sinusoidal brushless DC (BLDC) motor controller
• Manufacturer: Fairchild Semiconductor

© 2011 Fairchild Semiconductor Corporation
FCM8201 • Rev. 1.0.2
Digital-to-Analog Converter
FCM8201 has an 8-bit digital-to-analog converter (DAC)
to control the DUTY and IP through the SPI interface.
Analog to Digital Converter
FCM8201 has a 5-bit analog-to-digital converter (ADC)
for the signal on AS, VSENSE, I_FB, and RT pins. Its
voltage can be read through the SPI interface.
I/O Optional Function
The pins 5~8 of FCM8201 are two types of I/O for both
stand-alone
applications. FCM8201 uses stand-alone mode by
default. The microcontroller should use pin 7 (XP) and
pin 8 (XN) to complete the signal toggle procedure
Table 4. Timing Specification of I/O Function Selection
Symbol
t
t
t
t
RES
SEL
ACT
TR
Select-Bit Stable Time
Select-Bit Transient Time
Acknowledge Bit Pull Low Time
FCM8201 Response Time
and
microcontroller
Parameter
Figure 21.
Figure 22.
(SPI
I/O Select Timing of Entering SPI Mode
I/O Select Timing of Exiting SPI Mode
mode)
f
f
f
f
SYS
SYS
SYS
SYS
=1.28MHz
=1.28MHz
=1.28MHz
=1.28MHz
14
shown in Figure 21. In the way, FCM8201 activates SPI
operation mode. Afterwards, The pins 5~8 change to
SPI function.
To return from SPI mode to stand-alone mode, the
microcontroller has to complete the signal toggle
procedure shown in Figure 22.
SPI Interface
The microcontroller can access FCM8201 through the
SPI interface. In SPI operation mode, FCM8201
provides more motor control function than in stand-alone
operation mode. Please refer to the Table 6 and Table 7
for the details.
Conditions
Min.
12
0
Typ.
1
4
Max.
www.fairchildsemi.com
100
12
Unit
ms
µs
µs
µs