MCP47DA1 datasheet(29/76 Pages) MICROCHIP

29 / 76 page

 2012-2013 Microchip Technology Inc.

DS25118D-page 29

MCP47DA1

4.0

GENERAL OVERVIEW

The MCP47DA1 device is a general purpose DAC

intended to be used in applications where a program-

mable voltage output with moderate bandwidth is

desired.

Applications generally suited for the MCP47DA1

devices include:

• Computer servers

• Set point or offset trimming

• Sensor calibration

• Cost-sensitive mechanical trim pot replacement

The MCP47DA1 has four main functional blocks.

These are:

• POR/BOR Operation

• Serial Interface – I2C Module

• Resistor Network

• Output Buffer

The POR/BOR operation is discussed in this section

and the I2C and Resistor Network operation are

described in their own sections. The commands are

discussed in Section 5.3, Serial Commands.

Figure 4-1 shows a block diagram for the resistive

network of the device. An external pin, called VREF, is

the DAC’s reference voltage. The resistance from the

VREF pin to ground is typically 30 k. The reference

voltage connected to the VREF pin needs to support this

resistive load.

This resistor network functions as a windowed voltage

divider. This means that the VOUT pin’s voltage range is

from approximately 1/3 * VREF to approximately 2/3 *

VREF. This windowed range is determined by the 10 k

resistors (R1 and R2) that window the 10 k digital

potentiometer (see Figure 4-1).

FIGURE 4-1:

Resistor Network and

Output Buffer Block Diagram.

RFS

RW (1)

Analog Switch MUX

Note 1: The wiper resistance is tap dependent.

That is, each tap selection resistance

has a small variation.

RW (1)

RZS

2: The RFS and RZS resistances are

determined by the analog switches that

connect the resistor network to the other

circuitry.

VREF

Goes to Output

Buffer’s input

Op Amp

VOUT

MCP47DA1 датащи(PDF) 29 Page - Microchip Technology

MCP47DA1 датащи(HTML) 29 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

датащи скачать

ссылки URL