PIC16F1526 datasheet(150/354 Pages) MICROCHIP

150 / 354 page

PIC16(L)F1526/27

DS41458A-page 150

Preliminary

 2011 Microchip Technology Inc.

16.1

ADC Configuration

When configuring and using the ADC the following

functions must be considered:

• Port configuration

• Channel selection

• ADC voltage reference selection

• ADC conversion clock source

• Interrupt control

• Result formatting

16.1.1

PORT CONFIGURATION

The ADC can be used to convert both analog and

digital signals. When converting analog signals, the I/O

pin should be configured for analog by setting the

associated

TRIS

and

ANSEL

bits.

Refer

Section 12.0 “I/O Ports”

for more information.

16.1.2

CHANNEL SELECTION

There are 32 channel selections available:

• AN<29:0> pins

• Temperature Indicator

• FVR (Fixed Voltage Reference) Output

Refer to Section 14.0 “Fixed Voltage Reference

(FVR)”

and Section 15.0 “Temperature Indicator

Module”

for more information on these channel selec-

tions.

The CHS bits of the ADCON0 register determine which

channel is connected to the sample and hold circuit.

When changing channels, a delay is required before

starting the next conversion. Refer to Section 16.2

“ADC Operation”

for more information.

16.1.3

ADC VOLTAGE REFERENCE

The ADPREF bits of the ADCON1 register provides

control of the positive voltage reference. The positive

voltage reference can be:

•VREF+ pin

•VDD

• FVR 2.048V

• FVR 4.096V (Not available on LF devices)

See Section 14.0 “Fixed Voltage Reference (FVR)”

for more details on the Fixed Voltage Reference.

16.1.4

CONVERSION CLOCK

The source of the conversion clock is software select-

able via the ADCS bits of the ADCON1 register. There

are seven possible clock options:

•FOSC/2

•FOSC/4

•FOSC/8

•FOSC/16

•FOSC/32

•FOSC/64

•FRC (dedicated internal oscillator)

The time to complete one bit conversion is defined as

TAD. One full 10-bit conversion requires 11.5 TAD peri-

ods as shown in Figure 16-2.

For correct conversion, the appropriate TAD specifica-

tion must be met. Refer to the A/D conversion require-

ments in Section 25.0 “Electrical Specifications” for

more information. Table 16-1 gives examples of appro-

priate ADC clock selections.

Note:

Analog voltages on any pin that is defined

as a digital input may cause the input buf-

fer to conduct excess current.

Note:

Unless using the FRC, any changes in the

system clock frequency will change the

ADC

clock

frequency,

which

may

adversely affect the ADC result.

PIC16F1526 Datasheet(PDF) 150 Page - Microchip Technology

PIC16F1526 Datasheet(HTML) 150 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL