CS5501
CS5501
CS5503
CS5503
16 &
16- & 20-bit A/D Converters
Non-aliasing,
20-Bit A/D Converter
Features
I
Monolithic CMOS ADC with Filtering
-
6-pole, Low-pass Gaussian Filter
Description
The CS5501 and CS5503 are CMOS A/D converters
ideal for measuring low-frequency signals representing
physical, chemical, and biological processes. They uti-
lize charge-balance techniques to achieve 16-bit
(CS5501) and 20-bit (CS5503) performance with up to 4
kSps word rates.
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 kSps 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.
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
System Calibration Capability
Flexible Serial Communications Port
-
Microcontroller-compatible Formats
-
3-state Data and Clock Outputs
-
UART Format (CS5501 only)
Pin-selectable Unipolar/Bipolar Ranges
Low Power Consumption: 25 mW
-
10 µW Sleep Mode for Portable Applications
I
BP/UP SLEEP
SC1
SC2
CS5501
12
CS5503
BP/UPSLEEP
12
11
VREF
10
9
VREF
10
9
AIN
AIN
AGND
DGND
8
AGND 8
5
DGND 5
SC1
4
SC2
17
4
Calibration
Calibration
13
Calibration
Calibration
SRAM
Microcontroller
Microcontroller
SRAM
14
Charge-balanced A/D Converter
Charge-Balanced A/D Converter
7
Analog
6-pole Gaussian
Low-pass Digital
Analog
Modulator
6-Pole Gaussian
Filter
15
Modulator
Low-Pass Digital Filter
6
11
13
CAL
14
VA+
CAL
VA+
7
VA-
VA-
VD+
15
VD+
VD-
6
VD-
20
SDATA
SDATA
Clock Generator
Serial Interface
Clock Generator Serial Interface Logic
Logic
3
2
18
18
1
2
3
16 1
16
19
CLKIN
CLKOUT
CLKOUTCLKIN DRDY
DRDY
MODESCLK
CS
CS MODE
20
19
SCLK
Copyright Cirrus Logic,
2005
Copyright
©
Cirrus Logic, Inc.
Inc. 2003
(All
(All Rights Reserved)
Rights Reserved)
SEP
‘05
AUG
‘04
DS31F4
DS31F5
1
CIRRUS [ CIRRUS LOGIC ]
