DM163006 datasheet(197/320 Pages) MICROCHIP

197 / 320 page

 2001 Microchip Technology Inc.

Advance Information

DS39541A-page 197

PIC18C601/801

The value in the ADRESH/ADRESL registers is not

modified for a Power-on Reset. The ADRESH/ADRESL

registers will contain unknown data after a Power-on

Reset.

After the A/D module has been configured as desired,

the selected channel must be acquired before the con-

version is started. The analog input channels must

have their corresponding TRIS bits selected as an

input. To determine acquisition time, see Section 17.1.

After this acquisition time has elapsed, the A/D conver-

sion can be started. The following steps should be fol-

lowed to do an A/D conversion:

Configure the A/D module:

•

Configure analog pins, voltage reference

and digital I/O (ADCON1)

•

Select A/D input channel (ADCON0)

•

Select A/D conversion clock (ADCON2)

•

Turn on A/D module (ADCON0)

Configure A/D interrupt (if desired):

•

Clear ADIF bit

•

Set ADIE bit

•

Set GIE bit

Wait the required acquisition time.

Start conversion:

•

Set GO/DONE bit (ADCON0 register)

Wait for A/D conversion to complete, by either:

•

Polling for the GO/DONE bit to be cleared,

•

Waiting for the A/D interrupt

Read A/D Result registers (ADRESH:ADRESL);

clear bit ADIF, if required.

For next conversion, go to step 1 or step 2, as

required. The A/D conversion time per bit is

defined as TAD. A minimum wait of 2TAD is

required before next acquisition starts.

FIGURE 17-2:

ANALOG INPUT MODEL

VAIN

CPIN

ANx

5 pF

VDD

VT = 0.6 V

I leakage

RIC

≤ 1 k

Sampling

Switch

RSS

CHOLD = 120 pF

VSS

Sampling Switch

567 8 9 10 11

( k

Ω )

VDD

± 500 nA

Legend: CPIN

I LEAKAGE

RIC

CHOLD

= input capacitance

= threshold voltage

= leakage current at the pin due to

= interconnect resistance

= sampling switch

= sample/hold capacitance (from DAC)

various junctions

= sampling switch resistance

RSS

DM163006 Datasheet(PDF) 197 Page - Microchip Technology

DM163006 Datasheet(HTML) 197 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