AD7193BCPZ Analog Devices Inc, AD7193BCPZ Datasheet - Page 30

• Manufacturer Part Number: AD7193BCPZ
• Description: 4ch VeryLow Noise 24Bit SD ADC With PGA
• Manufacturer: Analog Devices Inc

Specifications of AD7193BCPZ

• Number Of Bits: 24
• Sampling Rate (per Second): 4.8k
• Data Interface: DSP, MICROWIRE™, QSPI™, Serial, SPI™
• Number Of Converters: 1
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 32-WFQFN, CSP Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AD7193
ADC CIRCUIT INFORMATION
OVERVIEW
The AD7193 is an ultralow noise ADC that incorporates a Σ-Δ
modulator, a buffer, PGA, and on-chip digital filtering intended
for the measurement of wide dynamic range signals such as
those in pressure transducers, weigh scales, and strain gage
applications. Figure 22 shows the basic connections required
to operate the part.
Analog Inputs
The device can be configured to have four differential or eight
pseudo differential analog inputs. The analog inputs can be
buffered or unbuffered.
Multiplexer
The on-chip multiplexer increases the channel count of the device.
Because the multiplexer is included on chip, any channel changes
are synchronized with the conversion process.
PGA
The analog input signal can be amplified using the PGA. The
PGA allows gains of 1, 8, 16, 32, 64, and 128.
Reference Detect
The AD7193 is capable of monitoring the external reference. If
the reference is not present, a flag is set in the status register of
the device.
Burnout Currents
Two 500 nA burnout currents are included on-chip to detect
the presence of the external sensor.
OUT–
IN+
IN–
5V
OUT+
REFIN1(+)
BPDSW
AIN1
AIN2
AIN3
AIN4
AIN5
AIN6
AIN7
AIN8
AINCOM
REFIN1(–)
AGND
MUX
AGND
Figure 22. Basic Connection Diagram
AGND
AV
AV
DD
AD7193
DD
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SENSOR
TEMP
PGA
MCLK1 MCLK2
CIRCUITRY
Sigma-Delta (Σ-Δ) ADC and Filter
The AD7193 contains a fourth-order Σ-Δ modulator followed
by a digital filter. The device has several filter options
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Serial Interface
The AD7193 has a 4-wire SPI interface. The on-chip registers
are accessed via the serial interface.
Clock
The AD7193 has an internal 4.92 MHz clock. Either this clock
or an external clock can be used as the clock source to the AD7193.
The internal clock can also be made available on a pin if a clock
source is required for external circuitry.
Bridge Power-Down Switch
External circuitry such as strain gages or bridges can be
powered up/down using the bridge power-down switch.
Temperature Sensor
The on-chip temperature sensor monitors the die temperature.
Digital Outputs
The AD7193 has four general-purpose digital outputs. These
can be used for driving external circuitry. For example, an
external multiplexer can be controlled by these outputs.
Calibration
Both internal and system calibration are included on chip;
therefore, the user has the option of removing offset/gain errors
internal to the AD7193 only, or removing the offset/gain errors
of the complete end system.
CLOCK
DV
MODULATOR
CALIBRATION
AND FILTER
Sinc
Sinc
Chop enabled/disabled
Fast settling
Zero latency
DD
Σ-Δ ADC
DGND
4
3
P0/REFIN2(–) P1/REFIN2(+)
INTERFACE
CONTROL
SERIAL
LOGIC
REFERENCE
AND
DETECT
DOUT/RDY
DIN
SCLK
CS
SYNC
P3
P2