ISL26132_14 Datasheet, PDF (1/23 Pages) Intersil Corporation – Low-Noise 24-bit Delta Sigma ADC

DATASHEET
Low-Noise 24-bit Delta Sigma ADC
ISL26132, ISL26134
The ISL26132 and ISL26134 are complete analog front ends
for high resolution measurement applications. These 24-bit
Delta-Sigma Analog-to-Digital Converters include a very
low-noise amplifier and are available as either two or four
differential multiplexer inputs. The devices offer the same
pinout as the ADS1232 and ADS1234 devices and are
functionally compatible with these devices. The ISL26132 and
ISL26134 offer improved noise performance at 10Sps and
80Sps conversion rates.
The on-chip low-noise programmable-gain amplifier provides
gains of 1x/2x/64x/128x. The 128x gain setting provides an
input range of ±9.766mVFS when using a 2.5V reference. The
high input impedance allows direct connection of sensors, such
as load cell bridges to ensure the specified measurement
accuracy without additional circuitry. The inputs accept signals
100mV outside the supply rails when the device is set for unity
gain.
The Delta-Sigma ADC features a third order modulator
providing up to 21.6-bit noise-free performance. The device
can be operated from an external clock source, crystal
(4.9152MHz typical), or the on-chip oscillator.
The two channel ISL26132 is available in a 24 Ld TSSOP
package and the four channel ISL26134 is available in a 28 Ld
TSSOP package. Both are specified for operation over the
automotive temperature range (-40°C to +105°C).
Features
• Up to 21.6 Noise-free bits
• Low noise amplifier with gains of 1x/2x/64x/128x
• RMS noise: 10.6nV @ 10Sps (PGA = 128x)
• Linearity error: 0.0002% FS
• Simultaneous rejection of 50Hz and 60Hz (@ 10Sps)
• Two (ISL26132) or four (ISL26134) channel differential
input multiplexer
• On-chip temperature sensor (ISL26132)
• Automatic clock source detection
• Simple interface to read conversions
• +5V Analog, +5 to +2.7V digital supplies
• Pb-Free (RoHS compliant)
• TSSOP packages: ISL26132, 24 pin; ISL26134, 28 pin
Applications
• Weigh scales
• Temperature monitors and controls
• Industrial process control
• Pressure sensors
AVDD
CAP
DVDD
INTERNAL
CLOCK
EXTERNAL
OSCILLATOR
XTALIN/CLOCK
XTALOUT
AIN1+
AIN1-
AIN2+
AIN2-
ISL26134
Only
AIN3+
AIN3-
AIN4+
AIN4-
INPUT
MULTIPLEXER
PGA
1x/2x/64x/
128x
ADC
SDO/RDY
SCLK
PWDN
A0 A1/TEMP AGND
GAIN0 GAIN1
CAP
DGND
VREF+
NOTE for A1/TEMP pin: Functions as A1 on ISL26134; Functions as TEMP on ISL26132
FIGURE 1. BLOCK DIAGRAM
VREF-
DGND DGND
SPEED
November 20, 2014
1
FN6954.3
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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