AD7631BCPZ Analog Devices Inc, AD7631BCPZ Datasheet - Page 19

• Manufacturer Part Number: AD7631BCPZ
• Description: IC,A/D CONVERTER,SINGLE,18-BIT,CMOS,LLCC,48PIN
• Manufacturer: Analog Devices Inc
• Series: PulSAR®r

Specifications of AD7631BCPZ

• Number Of Bits: 18
• Sampling Rate (per Second): 250k
• Data Interface: Serial, Parallel
• Number Of Converters: 1
• Power Dissipation (max): 120mW
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 48-VFQFN, CSP Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

ANALOG INPUTS
Input Range Selection
In parallel mode and serial hardware mode, the input range is
selected by using the BIPOLAR (bipolar) and TEN (10 V range)
inputs. See Table 6 for pin details and the Hardware
Configuration section and the Software Configuration section for
programming the mode selection with either pins or the
configuration register. Note that when using the configuration
register, the BIPOLAR and TEN inputs are don’t cares and
should be tied high or low.
NOTES
1. ANALOG INPUTS ARE DIFFERENTIAL (ANTIPHASE). SEE ANALOG INPUTS SECTION.
2. THE AD8021 IS RECOMMENDED. SEE DRIVER AMPLIFIER CHOICE SECTION.
3. THE CONFIGURATION SHOWN IS USING THE INTERNAL REFERENCE. SEE VOLTAGE REFERENCE INPUT/OUTPUT SECTION.
4. A 22µF CERAMIC CAPACITOR (X5R, 1206 SIZE) IS RECOMMENDED (FOR EXAMPLE, PANASONIC ECJ4YB1A226M).
5. OPTIONAL, SEE POWER SUPPLIES SECTION.
6. THE VCC AND VEE SUPPLIES SHOULD BE VCC = [VIN(MAX) + 2V] AND VEE = [VIN(MIN) – 2V] FOR BIPOLAR INPUT RANGES.
7. OPTIONAL LOW JITTER CNVST, SEE CONVERSION CONTROL SECTION.
8. A SEPARATE ANALOG AND DIGITAL GROUND PLANE IS RECOMMENDED, CONNECTED TOGETHER DIRECTLY UNDER THE ADC.
SEE VOLTAGE REFERENCE INPUT/OUTPUT SECTION.
FOR UNIPOLAR INPUT RANGES, VEE CAN BE 0V. SEE POWER SUPPLIES SECTION.
SEE LAYOUT GUIDELINES SECTION.
–7V TO –15.75V
+7V TO +15.75V
ANALOG
ANALOG
INPUT+
INPUT–
NOTE 6
SUPPLY
SUPPLY
SUPPLY (5V)
ANALOG
NOTE 1
NOTE 4
NOTE 2
U1
C
C
NOTE 2
U1
10µF
10µF
C
C
C
22µF
10µF
REF
2.7nF
2.7nF
15Ω
15Ω
Figure 27. Typical Connection Diagram Shown with Serial Interface and Serial Programmable Port
100nF
100nF
100nF
100nF
VCC
VEE
IN–
REF
REFBUFIN
REFGND
IN+
AVDD
NOTE 3
NOTE 5
AGND
10Ω
10µF
DGND
PDREF
Rev. A | Page 19 of 32
100nF
NOTE 3
AD7631
PDBUF
AGND
SUPPLY (5V)
NOTE 8
DIGITAL
DVDD
DGND
PD
Input Structure
Figure 28 shows an equivalent circuit for the input structure of
the AD7631.
OVDD
IN+ OR IN–
RD
100nF
MODE[1:0]
CS
VEE
D0/OB/2C
BIPOLAR
SCCLK
HW/SW
SDOUT
SDCLK
CNVST
OGND
SCCS
RESET
BUSY
SCIN
TEN
Figure 28. Simplified Analog Input
10µF
C
PIN
VCC
33Ω
OVDD
D1
D2
NOTE 7
DIGITAL
INTERFACE
SUPPLY
(2.5V, 3.3V, OR 5V)
D
RANGE ONLY
CLOCK
0V TO 5V
AVDD
D3
D4
SERIAL
PORT 1
MICROPROCESSOR/
SERIAL
PORT 2
R
AGND
MicroConverter
IN
DSP
C
AD7631
IN
®
/