DSPIC30F5011-20I/PTG Microchip Technology, DSPIC30F5011-20I/PTG Datasheet - Page 131

• Manufacturer Part Number: DSPIC30F5011-20I/PTG
• Description: IC, DSC, 16BIT, 66KB, 40MHZ 5.5V TQFP-64
• Manufacturer: Microchip Technology
• Series: DsPIC30Fr

Specifications of DSPIC30F5011-20I/PTG

• Core Frequency: 40MHz
• Core Supply Voltage: 5.5V
• Embedded Interface Type: CAN, I2C, SPI, UART
• No. Of I/o's: 52
• Flash Memory Size: 66KB
• Supply Voltage Range: 2.5V To 5.5V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

19.4
The conversion trigger will terminate acquisition and
start the requested conversions.
The SSRC<2:0> bits select the source of the
conversion trigger. The SSRC bits provide for up to four
alternate sources of conversion trigger.
When SSRC<2:0> = 000, the conversion trigger is
under software control. Clearing the SAMP bit will
cause the conversion trigger.
When SSRC<2:0> = 111 (Auto-Start mode), the
conversion trigger is under ADC clock control. The
SAMC bits select the number of ADC clocks between
the start of acquisition and the start of conversion. This
provides the fastest conversion rates on multiple chan-
nels. SAMC must always be at least one clock cycle.
Other trigger sources can come from timer modules or
external interrupts.
19.5
Clearing the ADON bit during a conversion will abort
the current conversion and stop the sampling
sequencing until the next sampling trigger. The
ADCBUF will not be updated with the partially
completed A/D conversion sample. That is, the
ADCBUF will continue to contain the value of the last
completed conversion (or the last value written to the
ADCBUF register).
If the clearing of the ADON bit coincides with an
auto-start, the clearing has a higher priority and a new
conversion will not start.
19.6
The ADC conversion requires 14 T
the ADC conversion clock is software selected, using a
6-bit counter. There are 64 possible options for T
EQUATION 19-1:
© 2008 Microchip Technology Inc.
Programming the Start of
Conversion Trigger
Aborting a Conversion
Selecting the ADC Conversion
Clock
T
AD
= T
CY
* (0.5*(ADCS<5:0> + 1))
CLOCK
ADC CONVERSION
AD
. The source of
AD
.
The internal RC oscillator is selected by setting the
ADRC bit.
For correct ADC conversions, the ADC conversion
clock (T
time of 334 nsec (for V
“Electrical Characteristics” for minimum T
other operating conditions.
Example 19-1 shows a sample calculation for the
ADCS<5:0> bits, assuming a device operating speed
of 30 MIPS.
EXAMPLE 19-1:
Since,
Sampling Time = Acquisition Time + Conversion Time
Therefore,
Sampling Rate =
If SSRC<2:0> = ‘111’ and SAMC<4:0> = ‘00001’
dsPIC30F5011/5013
Therefore,
Set ADCS<5:0> = 19
AD
ADCS<5:0> = 2
Minimum T
) must be selected to ensure a minimum T
Actual T
= ~200 kHz
= 1 T
= 15 x 334 nsec
AD
T
(15 x 334 nsec)
AD
CY
=
AD
= 2 •
= 19
=
= 334 nsec
DD
ADC CONVERSION
CLOCK AND SAMPLING
RATE CALCULATION
= 334 nsec
= 33.33 nsec (30 MIPS)
+ 14 T
T
33.33 nsec
= 5V). Refer to Section 23.0
1
T
T
CY
2
AD
33.33 nsec
CY
334 nsec
2
AD
(ADCS<5:0> + 1)
– 1
DS70116H-page 131
(19 + 1)
– 1
AD
under
AD