EVAL-AD7674CBZ Analog Devices Inc, EVAL-AD7674CBZ Datasheet - Page 17

• Manufacturer Part Number: EVAL-AD7674CBZ
• Description: BOARD EVALUATION FOR AD7674
• Manufacturer: Analog Devices Inc
• Series: PulSAR®r

Specifications of EVAL-AD7674CBZ

• Number Of Adc's: 1
• Number Of Bits: 18
• Sampling Rate (per Second): 800k
• Data Interface: Serial, Parallel
• Inputs Per Adc: 1 Differential
• Input Range: 0 ~ 5 V
• Power (typ) @ Conditions: 126mW @ 800kSPS
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: AD7674
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Transfer Functions
Except in 18-bit interface mode, the AD7674 offers straight
binary and twos complement output coding when using OB/ 2C .
See Figure 26 and Table 8 for the ideal transfer characteristic.
ANALOG INPUT+
ANALOG INPUT–
111...111
111...110
111...101
000...010
000...001
000...000
ADR421
2.5V REF
NOTE 1
–FS + 0.5 LSB
–FS
Figure 26. ADC Ideal Transfer Function
ANALOG
SUPPLY
NOTES
1. SEE VOLTAGE REFERENCE INPUT SECTION.
2. OPTIONAL CIRCUITRY FOR HARDWARE GAIN CALIBRATION.
3. THE AD8021 IS RECOMMENDED . SEE DRIVER AMPLIFIER CHOICE SECTION.
4. SEE ANALOG INPUTS SECTION.
5. OPTION, SEE POWER SUPPLY SECTION.
6. OPTIONAL LOW JITTER CNVST, SEE CONVERSION CONTROL SECTION.
NOTE 3
NOTE 3
100nF
(5V)
AD8021
–FS + 1 LSB
1MΩ
AD8021
NOTE 2
–
+
–
+
U1
U2
50Ω
50Ω
ANALOG INPUT
50kΩ
C
C
C
C
15Ω
100nF
15Ω
+
Figure 27. Typical Connection Diagram (Internal Reference Buffer, Serial Interface)
NOTE 1
47μF
C
10μF
REF
NOTE 4
NOTE 4
2.7nF
2.7nF
+FS – 1.5 LSB
100nF
REFBUFIN
IN+
IN–
REF
REFGND
AVDD
+FS – 1 LSB
03083-0-026
NOTE 5
20Ω
AGND
Rev. A | Page 17 of 28
+
10μ F
AD7674
DGND
100nF
Table 8. Output Codes and Ideal Input Voltages
Description
FSR – 1 LSB
FSR – 2 LSB
Midscale + 1 LSB
Midscale
Midscale – 1 LSB
–FSR + 1 LSB
–FSR
1
2
DVDD
DVDD
This is also the code for overrange analog input (V
above V
This is also the code for underrange analog input (V
below –V
REF
OVDD
REF
– V
+ V
REFGND
REFGND
MODE1
MODE0
PDBUF
SDOUT
CNVST
RESET
OGND
OB/2C
SCLK
BUSY
).
).
RD
CS
PD
100nF
Analog Input
V
4.095962 V
4.095924 V
31.25 μV
0 V
–31.25 μV
–4.095962 V
–4.096 V
REF
= 4.096 V
+
NOTE 6
50Ω
DVDD
10μ F
SERIAL PORT
DIGITAL SUPPLY
(3.3V OR 5V)
D
CLOCK
Straight
Binary
(Hex)
3FFFF
3FFFE
20001
20000
1FFFF
00001
00000
IN+
IN+
– V
1
2
– V
μC/μP/DSP
IN–
IN–
Twos
Complement
(Hex)
1FFFF
1FFFE
00001
00000
3FFFF
20001
20000
03083-0-027
AD7674
1
2