EVAL-AD974CB Analog Devices Inc, EVAL-AD974CB Datasheet - Page 2

• Manufacturer Part Number: EVAL-AD974CB
• Description: BOARD EVAL FOR AD974
• Manufacturer: Analog Devices Inc

Specifications of EVAL-AD974CB

• Rohs Status: RoHS non-compliant
• Number Of Adc's: 1
• Number Of Bits: 16
• Sampling Rate (per Second): 200k
• Data Interface: Serial
• Inputs Per Adc: 4 Single Ended
• Input Range: ±10 V
• Power (typ) @ Conditions: 120mW @ 200kSPS
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: AD974
• Lead Free Status / RoHS Status: Not Compliant

EVAL-AD974CB
OPERATING THE EVAL-AD974CB
The AD974-CB is a four-layer board carefully laid out and tested
to demonstrate the specific high accuracy performance of the
device. Figure 2 shows the schematics of the evaluation board.
Figure 3 shows the component side silkscreen. The layouts of
the board are given in:
Component Layer – Figure 4
Power Layer – Figure 5
Ground Layer – Figure 6
Circuit Side Layer – Figure 7.
The AD974-CB is a flexible design that enables the user to
choose among many different board configurations. The avail-
able test points are listed in Table IV and a description of each
selectable jumper is listed in Table V.
The evaluation board schematic shows the factory installed
jumper selections. The AD974 is configured for ± 10 V input
range on each channel, powered through the EVAL-CONTROL
BOARD, the AD780 external reference applied to the REF pin
and on-board R/C generation used. The serial interface is con-
figured to operate with its internal data clock, DCLK. Conver-
sion data is available at the outputs of two 8-bit shift registers,
U4 and U5, for parallel transfer via the 40-pin IDC connector,
J4, or the 96-pin DIN connector, P5. Additionally, conversion
results are available in serial format from the 20-pin connector,
P4. The AD974 conversion control inputs, R/C and CS, are
configured to provide continuous conversions with the CS
input set low and the R/C input connected to the output of
the counter, U6.
Power Supplies and Grounding
The AD974-CB power supply connectors and ground planes are
configured to provide the multiple power and grounding con-
figurations used in most system applications.
The evaluation board ground plane is separated into two sec-
tions: a plane for the digital interface circuitry and an analog
plane for the AD974 and its analog input and external reference
circuitry. To attain high resolution performance the board was
designed to ensure that all digital ground return paths do not
cross the analog ground return paths.
The EVAL-AD974CB has three power supply blocks: a single
+5 V supply for the AD974 V
+5 V supply for the digital interface circuitry (P2), and a ± 12 V
supply for the analog signal conditioning circuitry (P3). All
supplies are decoupled to ground with 10 µF tantalum and
0.1 µF ceramic capacitors. Figure 1 shows the recommended
power connection diagram.
+15V
POWER SUPPLIES
+V
GND
CC
P4
ANALOG
AGND
–15V
P3
–V
ANA
EE
and V
V
ANA
+5V GND
P1
AGND
DIG
P2
SYSTEM POWER
power pins (P1), a
DIGITAL
V
+5V GND
DIG
DGND
Analog Input Ranges
The AD974-CB provides the flexibility of operating the AD974
in each of its specified analog input ranges. Through easy to
follow jumper selections, the four channels of the AD974 can be
operated independently in the bipolar input range ± 10 V, or in
all two unipolar input ranges of 0 V to +4 V, and 0 V to +5 V.
Table I through Table III list the jumper configurations for each
input range.
Jumper Designation
JP12, JP27, JP23, JP25
JP11, JP26, JP22, JP24
Jumper Designation
JP12, JP27, JP23, JP25
JP11, JP26, JP22, JP24
Jumper Designation
JP12, JP27, JP23, JP25
JP11, JP26, JP22, JP24
Test Point
TP1
TP2
TP3
TP4
TP5
TP6
TP7
TP8
TP9
TP10
TP11
TP12
TP13
TP14
TP15
TP16
TP17
Table III. 0 V to +5 V Analog Input Range
Table II. 0 V to +4 V Analog Input Range
Table IV. EVAL-AD974CB Test Points
Table I.
10 V Analog Input Range
Header Shunt Position
B
B
Header Shunt Position
A
B
Header Shunt Position
A
A
Available Signal
AIN1 (BUFFERED)
BUSY
R/C
DGND
VDIG
AGND1
SYNC
DCLK
DATA
CAP
AGND
AIN1 (SMB)
–VCC
+VCC
VANA
AGND
R/C (BNC)