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. 1999
(All Rights Reserved)
Cirrus Logic, Inc.
Crystal Semiconductor Products Division
P.O. Box 17847, Austin, Texas 78760
(512) 445 7222 FAX: (512) 445 7581
http://www.crystal.com
CS5521
CS5523
2- or 4-Channel 16-Bit Buffered
∆Σ
Multi-Range ADC
Features
l
Delta-Sigma A/D Converter
— Linearity Error: 0.0015%FS
l
Buffered Bipolar/Unipolar Input Ranges
— 25 mV, 55 mV, 100 mV, 1 V, 2.5 V and 5 V
l
Chopper Stabilized Instrumentation Amplifier
l
On-Chip Charge Pump Drive Circuitry
l
Differential Multiplexer
l
Conversion Data FIFO
l
Programmable/Auto Channel Sequencer
l
2-Bit Output Latch
l
Simple three-wire serial interface
— SPI™ and Microwire™ Compatible
— Schmitt Trigger on Serial Clock (SCLK)
l
Output Settles in One Conversion Cycle
l
50/60 Hz ±3 Hz Simultaneous Rejection
l
Buffered V
REF
with +5 V Input Capability
l
System and Self-Calibration with R/W
Registers per Channel
l
5 V Analog Supply
+3.0 V or +5 V Digital Supply
l
Power Consumption: 5.5 mW
- 1.8 mW in 1 V, 2.5 V and 5 V input ranges
General Description
The 16-bit CS5521/23 are highly integrated
∆Σ
A/D con-
verters which include an instrumentation amplifier, a PGA
(programmable gain amplifier), a multi-channel multiplexer,
digital filters, and self and system calibration circuitry.
The chips are designed to provide their own negative
supply which enables their on-chip instrumentation am-
plifiers to measure bipolar ground-referenced signals
less-than or equal to ±100 mV.
The digital filters provide programmable output update
rates of 1.88 Hz, 3.76 Hz, 7.51 Hz, 15 Hz, 30 Hz,
61.6 Hz, 84.5 Hz, and 101.1 Hz when operating from a
32 kHz crystal. The CS5521/23 are capable of producing
output update rates up to 303 Hz with a 100kHz clock.
The filters are designed to settle to full accuracy for the
selected output update rate within one conversion cycle.
When operated at word rates of 15 Hz or less, the digital
filters reject both 50 and 60 Hz line interference
±
3 Hz
simultaneously.
Low power, single conversion settling time, programma-
ble output rates, and the ability to handle negative input
signals make these single supply products ideal solu-
tions for isolated and non-isolated applications.
ORDERING INFORMATION
See page 33.
VD+
DGND
Differential
4th order
delta-sigma
modulator
Digital Filter
Calibration
Register
Calibration
µ
C
VA+
Control
Register
XIN XOUT
Programmable
Gain
AGND
CS
SCLK
SDI
SDO
VREF-
CPD
NBV
X20
A0 A1
Calibration
Memory
VREF+
Latch
AIN1-
AIN1+
AIN2+
AIN2-
+
-
Output
Register
X1
X1
X1
MUX
CS5523
Shown
AIN3-
AIN3+
AIN4+
AIN4-
C lock
Gen.
MAR ‘99
DS317PP2
