MCP48FVB08 datasheet(89/112 Pages) MICROCHIP

89 / 112 page

 2020 Microchip Technology Inc.

DS20006362A-page 89

MCP48FXBX4/8

8.0

APPLICATIONS INFORMATION

The MCP48FXBX4/8 devices are general purpose,

quad/octal-channel voltage output DACs for various

applications, where a precision operation with

low-power and nonvolatile EEPROM memory is

needed.

Since the devices include a nonvolatile EEPROM

memory, the user can utilize these devices for

applications that require the output to return to the

previous setup value on subsequent power-ups.

8.1

Power Supply Considerations

The power source should be as clean as possible. The

power supply to the device is also used for the DAC

voltage reference internally if the internal VDD is

selected as the resistor ladder’s reference voltage

(VRnB:VRnA = 00).

Any noise induced on the VDD line can affect the DAC

performance. Typical applications will require a bypass

capacitor in order to filter out high-frequency noise on

the VDD line. The noise can be induced onto the power

supply’s traces or as a result of changes on the DAC out-

put. The bypass capacitor helps to minimize the effect of

these noise sources on signal integrity. Figure 8-1

shows an example of using two bypass capacitors (a

10 µF tantalum capacitor and a 0.1 µF ceramic capaci-

tor) in parallel on the VDD line. These capacitors should

be placed as close to the VDD pin as possible (within

4 mm). If the application circuit has separate digital and

analog power supplies, the VDD and VSS pins of the

device should reside on the analog plane.

When setting the part voltage reference to Band Gap

mode, the use of the VREF pin decoupling capacitors is

not recommended.

FIGURE 8-1:

Example Circuit.

Analog

VDD

SDI

SDO

VSS

VOUT0

To MCU

C1:

0.1 µF capacitor

= Ceramic

C2:

10 µF capacitor

= Tantalum

C3:

~0.1 µF

= Optional to reduce noise

in VOUT pin

C4:

0.1 µF capacitor

= Ceramic

C5:

10 µF capacitor

= Tantalum

C6:

0.1 µF capacitor

= Ceramic

Optional

(a) Circuit when VDD is selected as reference.

Note: VDD is connected to the reference circuit internally.

(b) Circuit when external reference is used.

Output

VREF

LAT/HVC

VOUTN

Analog

VDD

VREF

Analog

VOUT0

Optional

Output

VOUTN

SCK

SDI

SDO

VSS

To MCU

LAT/HVC

SCK

MCP48FVB08 Arkusz danych(PDF) 89 Page - Microchip Technology

MCP48FVB08 Arkusz danych(HTML) 89 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

Arkusz danych Pobierz

Link URL