AD7664 Analog Devices, AD7664 Datasheet - Page 12

• Manufacturer Part Number: AD7664
• Manufacturer: Analog Devices

Specifications of AD7664

• Resolution (bits): 16bit
• # Chan: 1
• Sample Rate: 570kSPS
• Interface: Par,Ser,SPI
• Analog Input Type: Diff-Uni
• Ain Range: (Vref) p-p,Uni (Vref)
• Adc Architecture: SAR
• Pkg Type: CSP,QFP

AD7664
The Normal Mode is the fastest mode (500 kSPS) without any
limitation on the time between conversions. This mode makes the
AD7664 ideal for asynchronous applications such as data
acquisition systems, where both high accuracy and fast sample
rate are required.
The Impulse Mode, the lowest power dissipation mode, allows
power saving between conversions. When operating at 100 SPS,
for example, it typically consumes only 21 µW. This feature
makes the AD7664 ideal for battery-powered applications.
Transfer Functions
Using the OB/2C digital input, the AD7664 offers two output
codings: straight binary and twos complement. The LSB size is
V
teristics for the AD7664 are shown in Figure 4 and Table II.
REF
/65536, which is about 38.15 µV. The ideal transfer charac-
ANALOG INPUT
111...111
111...110
111...101
000...010
000...001
000...000
(0V TO 2.5V)
Figure 4. ADC Ideal Transfer Function
ANALOG
SUPPLY
0.5 LSB
2.5V REF
0V
(5V)
1 LSB = V
1 LSB
1
U1
2
NOTES
1
2
3
REF
THE ADR421 IS RECOMMENDED WITH C
THE AD8021 IS RECOMMENDED WITH A COMPENSATION CAPACITOR C
OPTIONAL LOW JITTER CNVST.
C
C
REF
C
/65536
ANALOG INPUT
15
1
10 F
4.7nF
1 F
100nF
V
REF
REF
REFGND
IN
INGND
– 1.5 LSB
AVDD
Figure 5. Typical Connection Diagram
V
PD
REF
100
AGND
– 1 LSB
RESET
REF
10 F
= 47 F.
AD7664
DGND
–12–
100nF
CS
D
FSR – 1 LSB
FSR – 2 LSB
Midscale + 1 LSB
Midscale
Midscale – 1 LSB
–FSR + 1 LSB
–FSR
NOTES
1
2
TYPICAL CONNECTION DIAGRAM
Figure 5 shows a typical connection diagram for the AD7664.
This is also the code for overrange analog input (V
This is also the code for underrange analog input (V
V
escription
REF
DVDD
– V
Table II. Output Codes and Ideal Input Voltages
REFGND
OVDD
RD
C
).
= 10 pF, TYPE CERAMIC NPO.
SER/PAR
IMPULSE
SDOUT
CNVST
OGND
OB/2C
WARP
BUSY
SCLK
100nF
Analog
Input
2.499962 V
2.499923 V
1.250038 V
1.25 V
1.249962 V
38 µV
0 V
DVDD
10 F
D
3
SERIAL
PORT
CLOCK
DIGITAL SUPPLY
(3.3V OR 5V)
Digital Output Code
Straight
Binary
FFFF
FFFE
8001
8000
7FFF
0001
0000
IN
IN
– V
2
below V
1
C/ P/DSP
INGND
Hexa
above
INGND
Twos
Complement
7FFF
7FFE
0001
0000
FFFF
8001
8000
).
2
1
REV. E