EVAL-AD7403FMCZ Datasheet, PDF (7/20 Pages) Analog Devices – Full featured evaluation board

EVAL-AD7403FMCZ User Guide
EVALUATION BOARD HARDWARE
AD7403 DESCRIPTION
This user guide describes the evaluation board for the AD7403
isolated ADC. The AD7403 is a second-order, Σ-Δ modulator
that converts an analog input signal into a high speed, 1-bit data
stream with on-chip digital isolation based on Analog Devices,
Inc., iCoupler technology. The AD7403 operates from a
5 V (VDD1) power supply and accepts a differential input signal
of ±250 mV (±320 mV full scale). The differential input is
ideally suited to shunt voltage monitoring in high voltage
applications where galvanic isolation is required.
The analog input is continuously sampled by a high performance
analog modulator and converted to a ones density, digital
output stream with a data rate of up to 20 MHz. The original
information can be reconstructed with an appropriate digital
filter. The serial I/O can use a 5 V or a 3.3 V supply (VDD2).
The serial interface is digitally isolated. High speed CMOS,
combined with monolithic transformer technology, allows the on-
chip isolation to provide outstanding performance characteristics
that are superior to the performance of alternatives, such as
optocoupler devices. The AD7403 device is offered in a 16-lead,
wide-body SOIC package and has an operating temperature range
of −40°C to +125°C.
Complete specifications for the AD7403 device are provided in
the AD7403 data sheet and should be consulted in conjunction
with this user guide when using the evaluation board. Full
details on the EVAL-SDP-CH1Z are available on the SDP-H1
product page.
POWER SUPPLIES
Care should be taken before applying power and signals to
the evaluation board to ensure that all link positions are set
according to the required operating mode. See Table 2 for the
complete list of link options.
This evaluation board is designed to be supplied via the EVAL-
SDP-CH1Z. The EVAL-SDP-CH1Z generates 12 V and 3.3 V
UG-683
supply rails. The 12 V supply is connected to the on-board 5 V
linear regulator that supplies the ADuM6000 with power. The
ADuM6000 generates an isolated 5 V supply to power the VDD1
rail of the AD7403. The 3.3 V supply rail from the EVAL-SDP-
CH1Z is used to supply the VDD2 rail of the AD7403.
If the user wishes to supply VDD1 externally, an external power
supply in the range of 24 V ± 5% can be connected to the
HIGH_V connector, J7. Alternatively, an external supply in the
range of 5 V ± 10% can be connected to the J5 connector.
The VDD2 supply can also be supplied via an external power
supply in the range of 3 V to 5.5 V via the J6 connector.
There are two main ground planes: GND1 and GND2. These
planes are isolated with a creepage and clearance of 8 mm.
Caution
When the EVAL-AD7403FMCZ is connected to the EVAL-
SDP-CH1Z, care must be taken to ensure that if an external
voltage is supplied to the J6 input connector, the voltage does
not exceed 3.3 V. Exceeding this voltage may cause permanent
damage to the EVAL-SDP-CH1Z board.
INPUT SIGNALS
The analog input range to the AD7403 is ±250 mV (±320 mV
full scale), which should not be exceeded. An input signal in the
range of 500 mV p-p should be connected to the evaluation
board via the analog input connector, J1.
The EVAL-AD7403FMCZ has analog and digital ground planes
that are physically isolated from one other. As such, power to
the analog supply rail is by default, supplied through the on-
board ADuM6000 isolated iCoupler 5 kV, dc-to-dc converter.
VDD1 can optionally be supplied from the J5 external connector
or from the J7 high voltage external connector. A 24 V supply
connected to J7 is stepped down to 5 V by means of the on-
board ADP2441 step-down dc-to-dc regulator. See Table 2 for
more information about supplying VDD1 externally.
Table 1. External Power Supplies (Optional)
Power Supply
Connector
VDD1
J5
VDD2
J6
HIGH_V
J7
Voltage Range
5 V ± 10%
3 V to 5.5 V
3.3 V ± 5%
24 V ± 5%
Purpose
Analog supply rail
Digital supply rail without EVAL-SDP-CH1Z connected
Digital supply rail with EVAL-SDP-CH1Z connected
Analog supply rail (high voltage alternative to J5)
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