CS5532 Datasheet, PDF (1/50 Pages) Cirrus Logic – 24-bit ΔΣ ADCs with Ultra-low-noise PGIA

CS5532/34-BS
24-bit ∆Σ ADCs with Ultra-low-noise PGIA
Features
‰Chopper-stabilized PGIA (Programmable
Gain Instrumentation Amplifier, 1x to 64x)
– 6 nV/√Hz @ 0.1 Hz (No 1/f noise) at 64x
– 1200 pA Input Current with Gains >1
‰Delta-sigma Analog-to-digital Converter
– Linearity Error: 0.0007% FS
– Noise-free Resolution: Up to 23 bits
‰Two- or Four-channel Differential MUX
‰Scalable Input Span via Calibration
– ±5 mV to differential ±2.5V
‰Scalable V_REF Input: Up to Analog Supply
‰Simple Three-wire Serial Interface
– SPI™ and Microwire™ Compatible
– Schmitt Trigger on Serial Clock (SCLK)
‰R/W Calibration Registers Per Channel
‰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 CS5532/34 are highly integrated ∆Σ Analog-to-Digi-
tal Converters (ADCs) which use charge-balance
techniques to achieve 24-bit performance. The ADCs
are optimized for measuring low-level unipolar or bipolar
signals in weigh scale, process control, scientific, and
medical applications.
To accommodate these applications, the ADCs come as
either two-channel (CS5532) or four-channel (CS5534)
devices and include a very low-noise, chopper-stabilized
instrumentation amplifier (6 nV/√Hz @ 0.1 Hz) with se-
lectable gains of 1×, 2×, 4×, 8×, 16×, 32×, and 64×.
These ADCs also include a fourth-order ∆Σ modulator
followed 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 ADCs and a micro-
controller, the converters include 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 makes these ADCs ideal
solutions for weigh scale and process control
applications.
ORDERING INFORMATION
See page 47
VA+
C1
C2
VREF+ VREF-
VD+
AIN1+
AIN1-
AIN2+
AIN2-
AIN3+
AIN3-
AIN4+
AIN4-
MUX
(CS5534
SHOWN)
VA-
PGIA
1,2,4,8,16
32,64
DIFFERENTIAL
4^TH ORDER ∆Σ
MODULATOR
PROGRAMMABLE
SINC FIR FILTER
SERIAL
INTERFACE
CS
SDI
SDO
SCLK
LATCH
A0/GUARD
A1
CLOCK
GENERATOR
OSC1 OSC2
CALIBRATION
SRAM/CONTROL
LOGIC
DGND
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Copyright © Cirrus Logic, Inc. 2008
(All Rights Reserved)
OCT ‘08
DS755F3