AD7982BRMZ Analog Devices Inc, AD7982BRMZ Datasheet - Page 23

• Manufacturer Part Number: AD7982BRMZ
• Description: IC ADC 18BIT 1MSPS PULSAR 10MSOP
• Manufacturer: Analog Devices Inc
• Series: PulSAR®r

Specifications of AD7982BRMZ

• Data Interface: DSP, MICROWIRE™, QSPI™, Serial, SPI™
• Design Resources: Converting a Single-Ended Signal with AD7982 Differential PulSAR ADC (CN0032) Precision Single-Supply Differential ADC Driver for Industrial-Level Signals (CN0180)
• Number Of Bits: 18
• Sampling Rate (per Second): 1M
• Number Of Converters: 1
• Power Dissipation (max): 8.6mW
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 10-TFSOP (0.118", 3.00mm Width)
• Resolution (bits): 18bit
• Sampling Rate: 1MSPS
• Input Channel Type: Differential
• Supply Voltage Range - Analog: 2.375V To 2.625V
• Supply Current: 350nA
• Package: 10MSOP
• Resolution: 18 Bit
• Architecture: SAR
• Number Of Analog Inputs: 1
• Digital Interface Type: Serial (3-Wire, 4-Wire, SPI, QSPI, Microwire)
• Input Type: Voltage
• Signal To Noise Ratio: 98(Typ) dB
• Polarity Of Input Voltage: Bipolar
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AD7982
APPLICATION HINTS
LAYOUT
AD7982
The printed circuit board that houses the AD7982 should be
designed so that the analog and digital sections are separated
and confined to certain areas of the board. The pinout of the
AD7982, with its analog signals on the left side and its digital
signals on the right side, eases this task.
Avoid running digital lines under the device because these
couple noise onto the die, unless a ground plane under the
AD7982 is used as a shield. Fast switching signals, such as CNV
or clocks, should not run near analog signal paths. Crossover of
digital and analog signals should be avoided.
At least one ground plane should be used. It can be common or
split between the digital and analog sections. In the latter case,
the planes should be joined underneath the AD7982s.
Figure 41. Example Layout of the AD7982 (Top Layer)
The AD7982 voltage reference input REF has a dynamic input
impedance and should be decoupled with minimal parasitic
inductances. This is done by placing the reference decoupling
ceramic capacitor close to, ideally right up against, the REF and
GND pins and connecting them with wide, low impedance traces.
Finally, the power supplies VDD and VIO of the AD7982
should be decoupled with ceramic capacitors, typically 100 nF,
placed close to the AD7982 and connected using short, wide
traces to provide low impedance paths and to reduce the effect
of glitches on the power supply lines.
An example of layout following these rules is shown in
Figure 41 and Figure 42.
EVALUATING AD7982 PERFORMANCE
Figure 42. Example Layout of the AD7982 (Bottom Layer)
Other recommended layouts for the AD7982 are outlined
in the documentation of the evaluation board for the AD7982
(EVAL-AD7982CBZ). The evaluation board package includes
a fully assembled and tested evaluation board, documentation,
and software for controlling the board from a PC via the
EVAL-CONTROL
BRD3.
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