Preliminary Product Information

This document contains information for a new product.

Cirrus Logic reserves the right to modify this product without notice.

1

Copyright

 Cirrus Logic, Inc. 2000

(All Rights Reserved)

P.O. Box 17847, Austin, Texas 78760

(512) 445 7222 FAX: (512) 445 7581

http://www.cirrus.com

CS5540

Low-Power, Low-Voltage, 24 - Bit

∆Σ ADC

Features

l

∆Σ Analog-to-Digital Converter

- Linearity Error: 0.0015% FS

- RMS Noise: 4

µV

Voltage Reference Inputs

- Single Conversion Settling at 6.7 SPS

- Simultaneous 50/60 Hz Rejection

- Schmitt Trigger on Serial Clock (SCLK)

- Single +3.0 V Supply

- 330

µA Supply Current

- 10

µA in Sleep Mode

Description

The CS5540 is a low-power and low-voltage

∆Σ ana-

log-to-digital converter (ADC), which achieves highly

accurate conversions using a simple non-programmable

interface that is easy to understand and design-in. It is

optimized to convert analog signals in DC measurement

applications, such as temperature and pressure mea-

surement,

and

various

portable

devices

where

low-power consumption is required.

To accommodate these applications, the ADC integrates

analog input and reference buffers for increased input

impedance and a two-channel multiplexer.

The CS5540 includes a digital filter, which achieves si-

multaneous rejection of 50/60 Hz signals and provides

single conversion settling at 6.7 SPS throughput. Abso-

lute accuracy is achieved via continuous internal

self-calibration. The device draws a nominal 330 µA.

Low-power, low-voltage operation, and a simple serial

interface make the CS5540 an ideal device for low-cost,

power-conscious DC measurement applications.

ORDERING INFORMATION

CS5540-

AS

-40 ºC - +85 ºC

16-Pin SSOP

Differential

4th Order

∆Σ

Modulator

Digital

Filter

Serial

Interface

Calibration

Register

Output

Register

Input

Mux

Clock

Generator

X1

X1

X1

X1

VA+

VA-

VD+

DGND

VREF+

VREF-

OSC1 OSC2

AIN1+

AIN1-

AIN2+

AIN2-

SDO

SCLK

CS

CHS

JUN ‘01

DS503PP1