LTC1609ACSW datasheet(8/24 Pages) LINER

8 / 24 page

LTC1609

1609fa

16-BIT CAPACITIVE DAC

COMP

REF BUF

2.5V REF

CAP

(2.5V)

CSAMPLE

DATA

DATACLK

SYNC

BUSY

CONTROL LOGIC

R/C

PWRD

SB/BTC

EXT/INT

TAG

INTERNAL

CLOCK

ZEROING SWITCHES

VDIG

VANA

R1IN

R2IN

R3IN

REF

AGND1

AGND2

DGND

1609 BD

–

SUCCESSIVE APPROXIMATION

SERIAL INTERFACE

20k

10k

20k

FUNCTIONAL BLOCK DIAGRA

APPLICATIO S I FOR ATIO

Conversion Details

The LTC1609 uses a successive approximation algorithm

and an internal sample-and-hold circuit to convert an

analog signal to a 16-bit serial output. The ADC is complete

with a precision reference and an internal clock. The

control logic provides easy interface to microprocessors

and DSPs. (Please refer to the Digital Interface section for

timing information.)

Conversion start is controlled by the CS and R/C inputs. At

the start of conversion the successive approximation

it cannot be restarted.

During the conversion, the internal 16-bit capacitive DAC

output is sequenced by the SAR from the most significant

bit (MSB) to the least significant bit (LSB). Referring to

Figure 1, VIN is connected through the resistor divider to

the sample-and-hold capacitor during the acquire phase

and the comparator offset is nulled by the autozero switches.

In this acquire phase, a minimum delay of 2

µs will provide

enough time for the sample-and-hold capacitor to acquire

the analog signal. During the convert phase, the autozero

switches open, putting the comparator into the compare

mode. The input switch switches CSAMPLE to ground,

injecting the analog input charge onto the summing junc-

tion. This input charge is successively compared with the

binary-weighted charges supplied by the capacitive DAC.

Bit decisions are made by the high speed comparator. At

VDAC

1609 F01

–

CDAC

DAC

SAMPLE

HOLD

CSAMPLE

16-BIT

SHIFT REGISTER

COMPARATOR

SAMPLE

RIN2

RIN1

VIN

Figure 1. LTC1609 Simplified Equivalent Circuit

LTC1609ACSW Datasheet(PDF) 8 Page - Linear Technology

LTC1609ACSW Datasheet(HTML) 8 Page - Linear 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

Datasheet Descarga

Enlace URL