ADS1258IPHPREP datasheet(16/57 Pages) TI

16 / 57 page

AIN0

AIN1

AIN2

AIN3

AIN4

AIN5

AIN6

AIN7

AIN8

AIN9

AIN10

AIN11

AIN12

AIN13

AIN14

AIN15

AINCOM

Control

Logic

VREFP

VREFN

AVSS

PLLCAP

XTAL1

XTAL2

DRDY

PWDN

RESET

START

SPI

Interface

SCLK

DIN

DOUT

Digital Filter

Clock Control

16−Channel

MUX

AVDD

Sensor

Bias

MUXOUTP MUXOUTN

ADCINP

GND

ADCINN

ADC Channel Control

Supply Monitor

GPIO

GPIO[7:0]

DVDD

Temperature

Ext Ref Monitor

Internal Ref

ADC

CLKSEL

CLKIO

ADS1258-EP

SBAS445C – MARCH 2009 – REVISED DECEMBER 2009

www.ti.com

OVERVIEW

The ADS1258 is a flexible, 24-bit, low-noise ADC

VIN = (ADCINP – ADCINN), against the differential

optimized

for

fast

multi-channel,

high-resolution

reference input, VREF = (VREFP – VREFN). The

measurement systems. The converter provides a

digital

filter

receives

the

modulator

signal

and

maximum channel scan rate of 23.7kSPS, providing a

provides a low-noise digital output. The ADC channel

complete 16-channel scan in less than 700

μs.

block controls the multiplexer Auto-Scan feature.

Channel Auto-Scan occurs at a maximum rate of

Figure 34 shows the block diagram of the ADS1258.

23.7kSPS. Slower scan rates can be used with

The input multiplexer selects the analog input pins

corresponding increases in resolution.

connected

the

multiplexer

output

pins

(MUXOUTP/MUXOUTN). External signal conditioning

Communication is handled over an SPI-compatible

can be used between the multiplexer output pins and

serial interface with a set of simple commands

the

ADC

input

pins

(ADCINP/ADCINN)

the

providing control of the ADS1258. Onboard registers

multiplexer output can be routed internally to the ADC

store the various settings for the input multiplexer,

inputs without external circuitry. Selectable current

sensor detect bias, data rate selection, etc. Either an

sources within the input multiplexer can be used to

external 32.768kHz crystal, connected to pins XTAL1

bias sensors or detect for a failed sensor. On-chip

and XTAL2, or an external clock applied to pin CLKIO

system

function

readings

provide

readback

can be used as the clock source. When using the

temperature, supply voltage, gain, offset, and external

external

crystal

oscillator,

the

system

clock

reference.

available as an output for driving other devices or

controllers.

General-purpose

digital

I/Os

(GPIO)

The ADS1258 converter comprises a fourth-order,

provide input and output control of eight pins.

delta-sigma modulator followed by a programmable

digital

filter.

The

modulator

measures

the

differential

input

signal,

Figure 34. ADS1258 Block Diagram

Submit Documentation Feedback

Product Folder Link(s): ADS1258-EP

ADS1258IPHPREP датащи(PDF) 16 Page - Texas Instruments

ADS1258IPHPREP датащи(HTML) 16 Page - Texas Instruments

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

датащи скачать

ссылки URL