Техническая Спецификация для Microchip Technology MA330031-2
dsPIC33EPXXXGP50X, dsPIC33EPXXXMC20X/50X AND PIC24EPXXXGP/MC20X
DS70000657H-page 32
2011-2013 Microchip Technology Inc.
2.7
Oscillator Value Conditions
on
Device Start-up
If the PLL of the target device is enabled and
configured for the device start-up oscillator, the
maximum oscillator source frequency must be limited
to 3 MHz < F
configured for the device start-up oscillator, the
maximum oscillator source frequency must be limited
to 3 MHz < F
IN
< 5.5 MHz to comply with device PLL
start-up conditions. This means that if the external
oscillator frequency is outside this range, the
application must start-up in the FRC mode first. The
default PLL settings after a POR with an oscillator
frequency outside this range will violate the device
operating speed.
Once the device powers up, the application firmware
can initialize the PLL SFRs, CLKDIV and PLLFBD, to a
suitable value, and then perform a clock switch to the
Oscillator + PLL clock source. Note that clock switching
must be enabled in the device Configuration Word.
oscillator frequency is outside this range, the
application must start-up in the FRC mode first. The
default PLL settings after a POR with an oscillator
frequency outside this range will violate the device
operating speed.
Once the device powers up, the application firmware
can initialize the PLL SFRs, CLKDIV and PLLFBD, to a
suitable value, and then perform a clock switch to the
Oscillator + PLL clock source. Note that clock switching
must be enabled in the device Configuration Word.
2.8
Unused I/Os
Unused I/O pins should be configured as outputs and
driven to a logic low state.
Alternatively, connect a 1k to 10k resistor between V
driven to a logic low state.
Alternatively, connect a 1k to 10k resistor between V
SS
and unused pins, and drive the output to logic low.
2.9
Application
Examples
• Induction heating
• Uninterruptable Power Supplies (UPS)
• DC/AC inverters
• Compressor motor control
• Washing machine 3-phase motor control
• BLDC motor control
• Automotive HVAC, cooling fans, fuel pumps
• Stepper motor control
• Audio and fluid sensor monitoring
• Camera lens focus and stability control
• Speech (playback, hands-free kits, answering
• Uninterruptable Power Supplies (UPS)
• DC/AC inverters
• Compressor motor control
• Washing machine 3-phase motor control
• BLDC motor control
• Automotive HVAC, cooling fans, fuel pumps
• Stepper motor control
• Audio and fluid sensor monitoring
• Camera lens focus and stability control
• Speech (playback, hands-free kits, answering
machines, VoIP)
• Consumer audio
• Industrial and building control (security systems
• Industrial and building control (security systems
and access control)
• Barcode reading
• Networking: LAN switches, gateways
• Data storage device management
• Smart cards and smart card readers
Examples of typical application connections are shown
in
• Networking: LAN switches, gateways
• Data storage device management
• Smart cards and smart card readers
Examples of typical application connections are shown
in
through
.
FIGURE 2-4:
BOOST CONVERTER IMPLEMENTATION
I
PFC
V
OUTPUT
ADC Channel
Op Amp/
ADC Channel
PWM
k
1
k
2
k
3
FET
dsPIC33EP
V
INPUT
Comparator
Output
Driver