EVAL-AD7986EBZ Analog Devices Inc, EVAL-AD7986EBZ Datasheet - Page 14

• Manufacturer Part Number: EVAL-AD7986EBZ
• Description: 18-Bit A/D Converter Eval. Board
• Manufacturer: Analog Devices Inc
• Series: PulSAR®r

Specifications of EVAL-AD7986EBZ

• Silicon Manufacturer: Analog Devices
• Application Sub Type: ADC
• Kit Application Type: Data Converter
• Silicon Core Number: AD7986
• Kit Contents: Board
• Number Of Adc's: 1
• Number Of Bits: 18
• Sampling Rate (per Second): 2M
• Data Interface: Serial
• Inputs Per Adc: 1 Differential
• Input Range: ±VREF
• Power (typ) @ Conditions: 29mW @ 2MSPS
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: AD7986
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AD7986
Transfer Functions
The ideal transfer characteristic for the AD7986 is shown in
Figure 22 and Table 7.
011 ... 101
100 ... 010
100 ... 001
100 ... 000
011 ... 111
011 ... 110
–FSR + 0.5 LSB
–FSR
Figure 22. ADC Ideal Transfer Function
V
NOTES
1. GND REFERS TO REFGND, AGND, AND DGND.
0V TO V
REF
–FSR + 1 LSB
TO 0V
REF
ANALOG INPUT
V+
V+
V–
V–
+FSR – 1.5 LSB
2.7nF
2.7nF
15Ω
15Ω
+FSR – 1 LSB
Figure 23. Typical Application Diagram with Multiple Supplies
Rev. B | Page 14 of 28
IN+
IN–
10µF
BVDD
5V
AD7986
REF
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 AD7986 when multiple supplies are available.
This is also the code for an overranged analog input (V
This is also the code for an underranged analog input (V
AVDD,
DVDD
REFGND).
2.5V
GND
DD VIO
1
1.8V TO 2.7V
TURBO
SCLK
SDO
CNV
SDI
VIO
Analog Input
V
+4.095969 V
+31.25 µV
0 V
−31.25 µV
−4.095969 V
−4.096 V
3- OR 4-WIRE
INTERFACE:
SPI, CS
DAISY CHAIN (TURBO = LOW)
REF
= 5 V
IN+
IN+
Digital Output
Code (Hex)
0x1FFFF
0x00001
0x00000
0x3FFFF
0x20001
0x20000
− V
− V
IN−
IN−
above V
below REFGND).
1
2
REF
−