AD7783 Analog Devices, AD7783 Datasheet - Page 6
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AD7783
Manufacturer Part Number
AD7783
Description
Single-Channel, Read-Only, Pin-Configured, 24-bit Sigma-Delta A/D Converter with Switchable Current Sources
Manufacturer
Analog Devices
Datasheet
1.AD7783.pdf
(12 pages)
Specifications of AD7783
Resolution (bits)
24bit
# Chan
1
Sample Rate
n/a
Interface
Ser,SPI
Analog Input Type
Diff-Bip
Ain Range
0.32 V p-p,5.12 V p-p
Adc Architecture
Sigma-Delta
Pkg Type
SOP
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
AD7783BRUZ
Manufacturer:
ADI/亚德诺
Quantity:
20 000
AD7783
Pin No. Mnemonic
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
XTAL1
REFIN(+)
REFIN(–)
AIN(+)
AIN(–)
IOUT1
IOUT2
IPIN
RANGE
SCLK
CS
DOUT/RDY Serial Data Output/Data Ready Output. DOUT/RDY serves a dual purpose in this interface. When a conver-
MODE
GND
V
XTAL2
DD
Function
Input to the 32.768 kHz Crystal Oscillator Inverter.
Positive Reference Input. REFIN(+) can lie anywhere between V
ence voltage (REFIN(+) – REFIN(–)) is 2.5 V, but the part functions with a reference from 1 V to V
Negative Reference Input. This reference input can lie anywhere between GND and V
Analog Input. AIN(+) is the positive terminal of the fully differential analog input pair AIN(+)/AIN(–).
Analog Input. AIN(–) is the negative terminal of the fully differential analog input pair AIN(+)/AIN(–).
Output from Internal 200 mA Excitation Current Source. Either current source IEXC1 or IEXC2 can be
switched to this output using hardware control pin IPIN.
Output from Internal 200 mA Excitation Current Source. Either current source IEXC1 or IEXC2 can be
switched to this output using hardware control pin IPIN.
Logic Input that Selects the Routing of the On-Chip Current Sources. When IPIN is tied to GND, IEXC1
is routed to IOUT1 and IEXC2 is routed to IOUT2. When IPIN is tied to V
IOUT2 and IEXC2 is routed to IOUT1.
Logic Input that Configures the Input Range on the Internal PGA. With RANGE = 0, the full-scale input
range is ± 160 mV; the full-scale input range equals ± 2.56 V when RANGE = 1 for a 2.5 V reference.
Serial Clock Input/Output for Data Transfers from the ADC. When the device is operated in master mode,
SCLK is an output with one SCLK period equal to one XTAL period. In slave mode, SCLK is generated
by an external source. In slave mode, all the data can be transmitted on a continuous train of pulses. Alter-
natively, it can be a noncontinuous clock with the information being transmitted from the AD7783 in
smaller batches of data. SCLK is Schmitt triggered (slave mode), making the interface suitable for opto-
isolated applications.
Chip Select Input. CS is an active low logic input used to select the AD7783. When CS is low, the PLL
establishes lock and allows the AD7783 to initiate a conversion. When CS is high, the conversion is aborted,
DOUT and SCLK are three-stated, the AD7783 enters standby mode, and any conversion result in the
output shift register is lost.
sion is initiated, DOUT/RDY goes high and remains high until the conversion is complete. DOUT/RDY will
then return low to indicate that valid data is available to be read from the device. In slave mode, this acts as
an interrupt to the processor, indicating that valid data is available. If data is not read after a conversion,
DOUT/RDY will go high before the next update occurs. In master mode, DOUT/RDY goes low for at
least half an SCLK cycle before the device produces SCLKs. When SCLK becomes active, data is output
on the DOUT/RDY pin. Data is output on the falling SCLK edge and is valid on the rising edge.
The MODE pin selects master or slave mode of operation. When MODE = 0, the AD7783 operates in
master mode; the AD7783 is configured for slave mode when MODE = 1.
Ground Reference Point for the AD7783.
Supply Voltage, 3 V or 5 V Nominal.
Output from the 32.768 kHz Crystal Oscillator Inverter.
PIN FUNCTION DESCRIPTIONS
REFIN(+)
REFIN(–)
XTAL1
AIN(+)
AIN(–)
IOUT1
IOUT2
PIN CONFIGURATION
IPIN
1
2
3
4
5
6
7
8
(Not to Scale)
AD7783
TOP VIEW
–6–
16
15
14
13
12
11
10
9
XTAL2
V
GND
MODE
DOUT/RDY
CS
SCLK
RANGE
DD
DD
and GND + 1 V. The nominal refer-
DD
, IEXC1 is routed to
DD
– 1 V.
REV. C
DD
.