Cirrus Logic CS5530 User Manual

Copyright  Cirrus Logic, Inc. 2009
(All Rights Reserved)
http://www.cirrus.com
CS5530
24-bit ADC with Ultra-low-noise Amplifier
Features & Description
 Chopper-stabilized Instrumentation
Amplifier, 64X
• 12 nV/√Hz @ 0.1 Hz (No 1/f noise)
• 1200 pA Input Current

Digital Gain Scaling up to 40x
 Delta-sigma Analog-to-digital Converter
• Linearity Error: 0.0015% FS
• Noise Free Resolution: Up to 19 bits

Scalable V
REF
Input: Up to Analog Supply
 Simple Three-wire Serial Interface
• SPI™ and Microwire™ Compatible
• Schmitt-trigger on Serial Clock (SCLK)

Onboard Offset and Gain Calibration
Registers
 Selectable Word Rates: 6.25 to 3,840 Sps
 Selectable 50 or 60 Hz Rejection
 Power Supply Configurations
• VA+ = +5 V; VA- = 0 V; VD+ = +3 V to +5 V
• VA+ = +2.5 V; VA- = -2.5 V; VD+ = +3 V to +5 V
• VA+ = +3 V; VA- = -3 V; VD+ = +3 V
General Description
The CS5530 is a highly integrated ΔΣ Analog-to-Digital
Converter (ADC) which uses charge-balance techniques
to achieve 24-bit performance. The ADC is optimized for
measuring low-level unipolar or bipolar signals in weigh
scale, process control, scientific, and medical
applications.
To accommodate these applications, the ADC
includes
a very-low-noise, chopper-stabilized instrumentation
amplifier (12 nV/√Hz
@ 0.1 Hz) with a gain of 64X. This
device also includes a fourth-order ΔΣ modulator fol-
lowed by a digital filter
which provides twenty selectable
output word rates of 6.25, 7.5, 12.5, 15, 25, 30, 50, 60, 100,
120, 200, 240, 400, 480, 800, 960, 1600, 1920, 3200, and
3840 Sps (MCLK = 4.9152 MHz).
To ease communication between the ADC and a micro-
controller, the converter includes a simple three-wire se-
rial interface which is SPI and Microwire compatible with
a Schmitt-trigger input on the serial clock (SCLK).
High dynamic range, programmable output rates, and
flexible power supply options make this device an ideal
solution for weigh scale and process control
applications.
ORDERING INFORMATION
See page 35.
VA+ C1 C2 VREF+ VREF- VD+
DIFFERENTIAL
4
TH
ORDER ΔΣ
MODULATOR
PROGRAMMABLE
SINC FIR FILTER
AIN1+
AIN1-
SERIAL
INTERFACE
LATCH
CLOCK
GENERATOR
CALIBRATION
SRAM/CONTROL
LOGIC
DGND
CS
SDI
SDO
SCLK
OSC2OSC1A1A0VA-
64X
NOV ‘09
DS742F3

Cirrus Logic CS5530 Specifications

General

Brand	Cirrus Logic
Model	CS5530
Category	Media Converter
Language	English

Summary

Characteristics and Specifications

Analog Characteristics

Detailed analog performance parameters including linearity, offset, and noise.

Digital Characteristics

Electrical characteristics for digital inputs and outputs at 5V and 3V supplies.

Absolute Maximum Ratings

Limits for voltage, current, and temperature to prevent device damage.

Switching Characteristics

Timing parameters for serial interface, clock, and start-up.

General Description

Analog Input

Details the front-end instrumentation amplifier and input models.

ADC Register Structure and Operating Modes

Describes internal registers for calibration, configuration, and commands.

Calibration

Explains procedures for setting zero and gain slope of the ADC.

Performing Conversions

Details single and continuous conversion modes and timing.

Pin Descriptions

Control Pins and Serial Data I/O

Explains CS, SDI, SDO, SCLK, A0, and A1 pin functions.

Measurement and Reference Inputs

Details analog input and voltage reference pins.

Specification Definitions

Linearity Error

Definition of deviation from the ideal ADC transfer function.

Differential Nonlinearity

Definition of deviation in code width from ideal.

Full-scale Error

Definition of deviation of last code transition from ideal.

Package Drawings

Ordering Information

Environmental, Manufacturing, & Handling Information