CS5501-AP Datasheet, PDF (1/54 Pages) Cirrus Logic – Low-Cost, 16 & 20-Bit Measurement A/D Converter

CS5501
CS5503
Low-Cost, 16 & 20-Bit Measurement A/D Converter
Features
l Monolithic CMOS ADC with Filtering
- 6-Pole, Low-Pass Gaussian Filter
l Up to 4 kHz Output Word Rates
- On Chip Self-Calibration Circuitry
- Linearity Error: ±0.0003%
- Differential Nonlinearity:
CS5501: 16-Bit No Missing Codes
(DNL ±1/8 LSB)
CS5503: 20-Bit No Missing Codes
l System Calibration Capability
l Flexible Serial Communications Port
- µC-Compatible Formats
- 3-State Data and Clock Outputs
- UART Format (CS5501 only)
l Pin-Selectable Unipolar/Bipolar Ranges
l Low Power Consumption: 25 mW
- 10 µW Sleep Mode for Portable Applications
l Evaluation Boards Available
Description
The CS5501 and CS5503 are low-cost CMOS A/D con-
verters ideal for measuring low-frequency signals
representing physical, chemical, and biological process-
es. They utilize charge-balance techniques to achieve
16-bit (CS5501) and 20-bit (CS5503) performance with
up to 4 kHz word rates at very low cost.
The converters continuously sample at a rate set by the
user in the form of either a CMOS clock or a crystal. On-
chip digital filtering processes the data and updates the
output register at up to a 4 kHz rate. The converters’ low-
pass, 6-pole Gaussian response filter is designed to al-
low corner frequency settings from 0.1 Hz to 10 Hz in the
CS5501 and 0.5 Hz to 10 Hz in the CS5503. Thus, each
converter rejects 50 Hz and 60 Hz line frequencies as
well as any noise at spurious frequencies.
The CS5501 and CS5503 include on-chip self-calibra-
tion circuitry which can be initiated at any time or
temperature to insure offset and full-scale errors of typi-
cally less than 1/2 LSB for the CS5501 and less than
4 LSB for the CS5503. The devices can also be applied
in system calibration schemes to null offset and gain er-
rors in the input channel.
Each device’s serial port offers two general purpose
modes of operation for direct interface to shift registers
or synchronous serial ports of industry-standard micro-
controllers. In addition, the CS5501’s serial port offers a
third, UART-compatible mode of asynchronous
communication.
ORDERING INFORMATION
See page 33.
I
BP/UPSLEEP
12 11
Calibration
SRAM
SC1 SC2
4
Calibration
Microcontroller
VREF ¹⁰
AIN ⁹
Charge-Balanced A/D Converter
Analog
6-Pole Gaussian
Modulator Low-Pass Digital Filter
AGND ⁸
DGND ⁵
Clock Generator Serial Interface Logic
23
18 16 1 19
CLKOUTCLKIN DRDY CS MODESCLK
13 _CAL
14 _VA+
7 _VA-
15 _VD+
6 _VD-
20 _SDATA
Cirrus Logic, Inc.
Crystal Semiconductor Products Division
P.O. Box 17847, Austin, Texas 78760
[phone] FAX: [phone]
http://www.crystal.com
Copyright © Cirrus Logic, Inc. 1997
(All Rights Reserved)
MAR ‘95
DS31F2
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