UG-1882
Rev. 0 | Page 4 of 28
EVALUATION BOARD HARDWARE GUIDE
IN0
COM
IN1
CS
AD4696
160-PIN FMC
OR
12-PIN PMOD
+3.3V
–2.5V
+12V
V
REF
REFERENCE
BUFFER
POWER MANAGEMENT CIRCUITRY
REFERENCE
ON-BOARD
DC BIAS
CHANNEL 2
TO
CHANNEL 15
CNV
SDI
SCK
SDO
BSY_ALT_GP0
RESET
IN14
IN15
+1.8V
+5V
+7.5V
8-LEAD MSOP
DUAL OP AMPS
R
R
V
REF
REF
SM
A
CO
NNE
C
T
O
RS
CH0
AND CH1
V
REF
/2
25058-
002
Figure 2. EVAL-AD4696FMCZ Simplified Block Diagram
HARDWARE OVERVIEW
Figure 2 shows a simplified block diagram of the EVAL-
AD4696FMCZ hardware. This evaluation board features the
and peripheral circuitry required for evaluating the
device.
The EVAL-AD4696FMCZ is a quick start evaluation platform that
showcases the performance of the AD4696 with no or minimal
modifications required. Figure 24 to Figure 30 contain the EVAL-
AD4696FMCZ schematics. The evaluation board includes an
on-board 5 V reference, an ADC driver amplifier for all 16
AD4696 channels, the ability to configure driver amplifiers on
Channel IN0 and Channel IN1 in many common configurations,
and configurable dc voltage levels for the IN2 through the IN15
channels. By default, the EVAL-AD4696FMCZ is powered entirely
from the FMC connector supplies. The Analog Front-End section,
the Reference section, the Power Supplies section, and the
Digital Interface section describe the design of each of these
circuit blocks, how they are used to evaluate the AD4696, and
common hardware modifications for each.
ANALOG FRONT-END
The EVAL-AD4696FMCZ evaluation hardware includes an
ADC driver amplifier for each of the 16 analog inputs (IN0 to
IN15). The driver amplifiers (
and seven
devices to drive IN2 and IN15) come in a
common dual-amplifier, 8-lead MSOP package, which allows
multiple ADC driver options to be evaluated with the AD4696
on the EVAL-AD4696FMCZ.
Channel IN0 and Channel IN1 have been configured to
demonstrate ac performance of the AD4696, whereas Channel
IN2 through Channel IN15 have been configured to demonstrate
simple noise measurements and signal settling measurements
with dc voltages generated on board. The amplifiers driving
Channel IN0 and Channel IN1 can be configured to perform
common signal conditioning functions by adding specific passive
components (see the Evaluating AD4696 AC Performance section).
The amplifiers driving Channel IN2 to Channel IN15 are driven
to dc voltages by on-board amplifiers and user configurable
resistor dividers (see the Configuring DC Channels (IN2
Through IN15) section).
Evaluating AD4696 AC Performance (IN0 and IN1)
The EVAL-AD4696FMCZ hardware includes two channels for
evaluating the ac performance of the AD4696 using a precision
ac signal generator.
Component A0 includes two amplifiers that function as the
ADC drivers for the AD4696 IN0 and IN1 inputs. By default,
A0 is populated with the ADA4805-2 due to its low noise and low
distortion that makes it suitable for ac performance evaluation.
The Subminiature Version A (SMA) connectors, J1 through J4,
are routed to the inputs of A0 via the signals labeled CH0 and
CH1 in Figure 24 and Figure 26.
The J1 through J4 SMA connectors are shown in Figure 24. To
apply an ac signal to the IN0 channel, connect the ac signal
generator output to J1 or J3. Likewise, to apply an ac signal to
the IN1 channel, connect the ac signal generator output to J2 or
J4. The ac signal generator must have similar or lower noise and
distortion specifications to the AD4696 to properly evaluate
AD4696 ac performance (see the AD4696 data sheet for
AD4696 device specifications).
The IN0 and IN1 channel amplifiers in A0 can be configured to
implement common feedback topologies including a unity-gain
buffer, non inverting or inverting amplifier, and active filters, by
populating the surrounding passive components appropriately
