ADAS3022BCPZ datasheet(22/40 Pages) AD

22 / 40 page

ADAS3022

Data Sheet

Rev. A | Page 22 of 40

THEORY OF OPERATION

OVERVIEW

The ADAS3022 is the first system on a single chip that integrates

the typical components used in a data acquisition system in one

easy to use, programmable device. This single-chip solution is

capable of converting up to 1,000,000 samples per second

(1 MSPS) of aggregate throughput. The ADAS3022 features

•

High impedance inputs

•

High common-mode rejection

•

8-channel, low crosstalk multiplexer (mux)

•

Programmable gain instrumentation amplifier (PGIA) with

seven selectable differential input ranges from ±0.64 V to

±24.576 V

•

16-bit PulSAR® ADC with no missing codes

•

Internal, precision, low drift 4.096 V reference and buffer

•

Temperature sensor

•

Channel sequencer

The ADAS3022 uses an Analog Devices patented high voltage

iCMOS® process, allowing up to a ±24.576 V differential input

voltage range when using ±15 V supplies, which makes the

device suitable for industrial applications.

The device is housed in a small, 6 mm × 6 mm, 40-lead LFCSP

and can operate over the industrial temperature range (−40°C

to +85°C). A typical discrete multichannel data acquisition

system containing similar circuitry would require at least three

times more space on the circuit board. Therefore, advantages of

the ADAS3022 solution include reduced footprint and less

complex design requirements, which also results in faster time

to market and lower cost.

ADAS3022 OPERATION

As shown in Figure 51, the ADAS3022 internal analog circuitry

consists of a high impedance, low leakage multiplexer and a

programmable gain instrumentation amplifier that can accept

full-scale differential voltages of ±0.64 V, ±1.28 V, ±2.56 V, ±5.12 V,

±10.24 V, ±20.48 V, and ±24.576 V. The ADAS3022 can be con-

figured to use up to eight single-ended input channels or four

pairs of channels, that is, 125 kSPS per channel for eight channels

or effectively 250 kSPS for four channel pairs. The device can also

provide a relative temperature measurement using the internal

temperature sensor. In addition, the differential auxiliary channel

pair (AUX+ and AUX−) is provided with the specified input

range of ±VREF. This option bypasses the mux and PGIA stages,

allowing direct access to the SAR ADC core.

Reducing the number of channels or pairs increases the throughput

rate by an amount proportional to the reciprocal of the number

of sampled channels multiplied by the aggregate throughput:

1/(Number of Channels or Pairs) × 1000 kSPS

For a single channel or channel pair, the maximum throughput

rate is 1 MSPS. For all eight channels, the AUX channel pair, and

the temperature sensor, the throughput rate of a given channel

decreases to 100 kSPS.

IN4

IN5

IN3

IN2

BUF

IN6

IN7

IN1

IN0

IN0/IN1

PAIR

DIFF TO

DIFF

COM

IN2/IN3

IN4/IN5

IN6/IN7

PulSAR

ADC

LOGIC/

INTERFACE

REFIN

REF

REFx

CNV

RESET

SCK

DIN

SDO

VSSH

VDDH

AGND

VIO

DVDD

AVDD

DGND

COM

AUX+

AUX–

BUSY

ADAS3022

MUX

TEMP

SENSOR

PGIA

Figure 51. ADAS3022 Simplified Block Diagram

ADAS3022BCPZ датащи(PDF) 22 Page - Analog Devices

ADAS3022BCPZ датащи(HTML) 22 Page - Analog Devices

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

датащи скачать

ссылки URL