EVAL-AD7686CB Analog Devices Inc, EVAL-AD7686CB Datasheet - Page 24

• Manufacturer Part Number: EVAL-AD7686CB
• Description: BOARD EVALUATION FOR AD7686
• Manufacturer: Analog Devices Inc
• Series: PulSAR®r

Specifications of EVAL-AD7686CB

• Number Of Adc's: 1
• Number Of Bits: 16
• Sampling Rate (per Second): 500k
• Data Interface: Serial
• Inputs Per Adc: 1 Differential
• Input Range: ±VREF
• Power (typ) @ Conditions: 15mW @ 500kSPS, 5 V
• Voltage Supply Source: Single
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: AD7686
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

AD7686
TRUE 16-BIT ISOLATED APPLICATION EXAMPLE
In applications where high accuracy and isolation are required,
such as power monitoring, motor control, and some medical
equipment, the circuit shown in Figure 47, using the AD7686
and the
high performance solution.
Multiple AD7686 devices are daisy-chained to reduce the
number of signals to isolate. Note that the SCKOUT, which is a
readback of the AD7686 clock, has a very short skew with the
DATA signal.
ADuM1402C
±10V INPUT
±10V INPUT
±10V INPUT
±10V INPUT
digital isolator, provides a compact and
2V REF
2V REF
2V REF
2V REF
4kΩ
4kΩ
4kΩ
4kΩ
1/4 AD8618
1/4 AD8618
1/4 AD8618
1/4 AD8618
1kΩ
1kΩ
1kΩ
1kΩ
5V
5V
5V
5V
5V REF
5V REF
5V REF
5V REF
Figure 47. A True 16-Bit Isolated Simultaneous Sampling Acquisition System
10µF
10µF
10µF
10µF
IN+
IN+
IN+
IN+
REF VDD VIO
REF VDD VIO
REF VDD VIO
REF VDD VIO
IN– GND
IN– GND
IN– GND
IN–
GND
AD7686
AD7686
AD7686
AD7686
Rev. B | Page 24 of 28
100nF
100nF
100nF
100nF
5V
5V
5V
5V
SDO
SCK
CNV
SCK
CNV
SCK
CNV
SDO
SCK
CNV
SDO
SDO
SDI
SDI
SDI
SDI
This skew is the channel-to-channel matching propagation
delay of the digital isolator (t
serial interface at the maximum speed of the digital isolator
(45 Mbps for the ADuM1402C), which would have been
otherwise limited by the cascade of the propagation delays of
the digital isolator. For instance, four AD7686 devices running
at 330 kSPS can be chained together.
The complete analog chain runs on a single 5 V supply using
the
CMOS
100nF
ADR391
5V
5V
AD8618
IN
ADR391
GND
low dropout reference voltage and the rail-to-rail
V
GND
V
V
V
V
DD1
OUT
OC
OD
IA
IB
amplifier while offering true bipolar input range.
1kΩ
1
, V
E1
10μF
ADuM1402C
1kΩ
1kΩ
5V
100nF
V
PSKCD
DD2
GND
4kΩ
, V
V
V
V
V
5V REF
). This allows running the
OA
OB
IC
ID
E2
2V REF
2
DATA
SCKOUT
SCKIN
CONVERT
100nF
2.7V TO 5V