EVAL-AD7944EBZ Analog Devices Inc, EVAL-AD7944EBZ Datasheet - Page 14

• Manufacturer Part Number: EVAL-AD7944EBZ
• Description: BOARD EVAL FOR AD7944
• Manufacturer: Analog Devices Inc
• Series: PulSAR®r

Specifications of EVAL-AD7944EBZ

• Number Of Adc's: 1
• Number Of Bits: 14
• Sampling Rate (per Second): 2.5M
• Data Interface: SPI™, QSPI™, MICROWIRE™, and DSP
• Inputs Per Adc: 1 Differential
• Input Range: 0 ~ 5 V
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: AD7944
• Silicon Manufacturer: Analog Devices
• Application Sub Type: ADC
• Kit Application Type: Data Converter
• Silicon Core Number: AD7944
• Kit Contents: Board And Literature
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AD7944
Transfer Functions
The ideal transfer characteristic for the AD7944 is shown in
Figure 22 and Table 7.
000 ... 010
000 ... 001
000 ... 000
111 ... 111
111 ... 110
111 ... 101
–FSR + 0.5 LSB
–FSR
Figure 22. ADC Ideal Transfer Function
–FSR + 1 LSB
0V TO V
NOTES
1. GND REFERS TO REFGND, AGND, AND DGND.
ANALOG INPUT
REF
+FSR – 1.5 LSB
V+
V–
Figure 23. Typical Application Diagram with Multiple Supplies
+FSR – 1 LSB
15Ω
2.7nF
Rev. A | Page 14 of 28
IN+
IN–
10µF
BVDD
REF
5V
AD7944
Table 7. Output Codes and Ideal Input Voltages
Description
FSR − 1 LSB
Midscale + 1 LSB
Midscale
Midscale − 1 LSB
−FSR + 1 LSB
−FSR
1
2
TYPICAL CONNECTION DIAGRAM
Figure 23 shows an example of the recommended connection
diagram for the AD7944 when multiple supplies are available.
AVDD,
DVDD
GND
This is also the code for an overranged analog input (V
This is also the code for an underranged analog input (V
REFGND).
V
2.5V
REF
− REFGND).
1.8V
2.7V
VIO
TO
TURBO
SDO
SCK
CNV
SDI
Analog Input,
V
4.09575 V
2.04825 V
2.048 V
2.04775 V
250 µV
0 V
3- OR 4-WIRE
INTERFACE:
SPI, CS,
DAISY CHAIN
(TURBO = LOW)
VIO
REF
= 4.096 V
Digital Output
Code (Hex)
0x3FFF
0x2001
0x2000
0x1FFF
0x0001
0x0000
IN+
IN+
− V
− V
IN−
1
2
IN−
above
below