8-Channel DAS with 18-Bit, Bipolar,
Simultaneous Sampling ADC
Data Sheet
AD7608
FEATURES
APPLICATIONS
8 simultaneously sampled inputs
True bipolar analog input ranges: ±10 V, ±± V
Single ± V analog supply and 2.3 V to ±.2± V VDRIVE
Fully integrated data acquisition solution
Analog input clamp protection
Power line monitoring and protection systems
Multiphase motor controls
Instrumentation and control systems
Multiaxis positioning systems
Data acquisition systems (DAS)
Input buffer with 1 MΩ analog input impedance
Second-order antialiasing analog filter
On-chip accurate reference and reference buffer
18-bit ADC with 200 kSPS on all channels
Oversampling capability with digital filter
Flexible parallel/serial interface
SPI/QSPI™/MICROWIRE™/DSP compatible
Pin compatible solutions from 14-bits to 18-bits
Performance
7 kV ESD rating on analog input channels
98 dB SNR, −107 dB THD
Low power: 100 mW
Standby mode: 2± mW
64-lead LQFP package
COMPANION PRODUCTS
External References: ADR421, ADR431
Digital Isolators: ADuM1402, ADuM±000, ADuM±402
Voltage Regulator Design Tool: ADIsimPower, Supervisor
Parametric Search
Complete list of complements on AD7608 product page
Table 1. High Resolution, Bipolar Input, Simultaneous
Sampling DAS Solutions
Single-
Ended
Resolution Inputs
True
Number of
Differential Simultaneous
Inputs
Sampling Channels
18 Bits
16 Bits
AD76081
AD7606
AD7609
8
8
6
4
8
AD7606-6
AD7606-4
AD7607
14 Bits
FUNCTIONAL BLOCK DIAGRAM
AV
CC
AV
CC
REGCAP REGCAP REFCAPB REFCAPA
R
1MΩ
FB
V1
CLAMP
CLAMP
T/H
SECOND
ORDER LPF
V1GND
2.5V
LDO
2.5V
LDO
R
R
FB
FB
1MΩ
1MΩ
REFIN/REFOUT
V2
CLAMP
CLAMP
T/H
T/H
T/H
T/H
T/H
T/H
T/H
SECOND
V2GND
ORDER LPF
R
R
FB
FB
1MΩ
1MΩ
REF SELECT
AGND
2.5V
REF
V3
CLAMP
CLAMP
OS 2
OS 1
OS 0
SECOND
ORDER LPF
V3GND
R
R
FB
FB
1MΩ
1MΩ
V4
CLAMP
CLAMP
D
D
A
B
SECOND
ORDER LPF
OUT
V4GND
SERIAL
R
R
FB
FB
1MΩ
1MΩ
OUT
8:1
MUX
PARALLEL/
SERIAL
RD/SCLK
CS
DIGITAL
FILTER
18-BIT
SAR
V5
CLAMP
CLAMP
INTERFACE
SECOND
ORDER LPF
V5GND
R
R
FB
FB
1MΩ
1MΩ
PAR/SER SEL
V
DRIVE
V6
CLAMP
CLAMP
SECOND
ORDER LPF
PARALLEL
DB[15:0]
V6GND
R
R
FB
FB
1MΩ
1MΩ
AD7608
V7
CLAMP
CLAMP
SECOND
ORDER LPF
V7GND
CLK OSC
R
R
FB
FB
1MΩ
1MΩ
BUSY
CONTROL
INPUTS
V8
CLAMP
CLAMP
SECOND
ORDER LPF
FRSTDATA
V8GND
R
FB
1MΩ
AGND
CONVST A CONVST B RESET RANGE
Figure 1.
1 Patent pending.
Rev. A
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