AD7403 Datasheet, PDF (1/25 Pages) Analog Devices – 16-Bit, Isolated Sigma-Delta Modulator

Data Sheet
16-Bit, Isolated Sigma-Delta Modulator
AD7403
FEATURES
5 MHz to 20 MHz external clock input rate
16 bits, no missing codes
Signal-to-noise ratio (SNR): 88 dB typical
Effective number of bits (ENOB): 14.2 bits typical
Offset drift vs. temperature
AD7403: 1.6 µV/°C typical
AD7403-8: 2 µV/°C typical
On-board digital isolator
On-board reference
Full-scale analog input range: ±320 mV
Operating range
AD7403: −40°C to + 125°C
AD7403-8: −40°C to + 105°C
High common-mode transient immunity: >25 kV/µs
Wide-body SOIC with increased creepage package
Slew rate limited output for low EMI
Safety and regulatory approvals
UL recognition
5000 V rms for 1 minute per UL 1577
CSA Component Acceptance Notice 5A
VDE Certificate of Conformity
DIN V VDE V 0884-10 (VDE V 0884-10):2006-12
VIORM = 1250 VPEAK
APPLICATIONS
Shunt current monitoring
AC motor controls
Power and solar inverters
Wind turbine inverters
Data acquisition systems
Analog-to-digital and optoisolator replacements
GENERAL DESCRIPTION
The AD7403¹ is a high performance, second-order, Σ-Δ modulator
that converts an analog input signal into a high speed, single-bit
data stream, with on-chip digital isolation based on Analog
Devices, Inc., iCoupler® technology. The device 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
1 _{Protected by U.S. Patents 5,952,849; 6,873,065; and 7,075,329.}
Rev. B
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FUNCTIONAL BLOCK DIAGRAM
V_DD1
V_DD2
BUF
V_IN+
V_IN–
REF
Σ-Δ ADC
CLK
DECODER
DATA
ENCODER
AD7403
CLK
ENCODER
MCLKIN
(5MHz
TO 20MHz)
DATA
DECODER
MDAT
GND₁
Figure 1.
GND₂
information can be reconstructed with an appropriate digital
filter to achieve 88 dB signal to noise ratio (SNR) at 78.1 kSPS.
The serial input/output can use a 5 V or a 3 V supply (VDD2).
The serial interface is digitally isolated. High speed complementary
metal oxide semiconductor (CMOS) technology, combined with
monolithic transformer technology, means the on-chip isolation
provides outstanding performance characteristics, superior to
alternatives such as optocoupler devices. The AD7403 device is
offered in a 16-lead, wide-body SOIC package and has an oper-
ating temperature range of −40°C to +125°C. The AD7403-8
device is offered in an 8-lead, wide-body SOIC package and has
an operating temperature range of −40°C to +105°C.
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