AD7298-1 Analog Devices, AD7298-1 Datasheet

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AD7298-1

Manufacturer Part Number
AD7298-1
Description
8-Channel, 1 MSPS, 10-Bit SAR ADC
Manufacturer
Analog Devices
Datasheet

Specifications of AD7298-1

Resolution (bits)
10bit
# Chan
8
Sample Rate
1MSPS
Interface
SPI
Analog Input Type
SE-Uni
Ain Range
Uni (Vref),Uni 1.0V,Uni 1.25,Uni 2.0V,Uni 2.5V
Adc Architecture
SAR
Pkg Type
CSP

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
AD7298-1BCPZ
Manufacturer:
ADI
Quantity:
200
FEATURES
10-bit SAR ADC
Temperature range: −40°C to +125°C
Specified for V
Logic voltage V
Power-down current: <10 µA
Internal 2.5 V reference
Internal power-on reset
High speed serial interface SPI
20-lead LFCSP
GENERAL DESCRIPTION
The AD7298-1 is a 10-bit, high speed, low power, 8-channel,
successive approximation ADC. The part operates from a single
3.3 V power supply and features throughput rates up to 1 MSPS.
The device contains a low noise, wide bandwidth track-and-hold
amplifier that can handle input frequencies in excess of 30 MHz.
The AD7298-1 offers a programmable sequencer, which enables
the selection of a preprogrammable sequence of channels for
conversion. The device has an on-chip, 2.5 V reference that can
be disabled to allow the use of an external reference.
The device offers a 4-wire serial interface compatible with SPI and
DSP interface standards.
The AD7298-1 uses advanced design techniques to achieve very
low power dissipation at high throughput rates. The part also
offers flexible power/throughput rate management options. The
part is offered in a 20-lead LFCSP package.
Rev. A
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
8 single-ended inputs
Channel sequencer functionality
Fast throughput of 1 MSPS
Analog input range: 0 V to 2.5 V
DD
DRIVE
of 2.8 V to 3.6 V
= 1.65 V to 3.6 V
8-Channel, 1 MSPS, 10-Bit SAR ADC
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.461.3113
PRODUCT HIGHLIGHTS
1.
2.
3.
V
V
V
REF
Ideally Suited to Monitoring System Variables in a Variety
of Systems. This includes telecommunications, and process
and industrial control.
High Throughput Rate of 1 MSPS with Low Power
Consumption.
Eight Single-Ended Inputs with a Channel Sequencer. A
consecutive sequence of channels can be selected on which
the ADC cycles and converts.
IN0
IN7
FUNCTIONAL BLOCK DIAGRAM
INPUT
V
MUX
PD/RST
DD
©2010–2011 Analog Devices, Inc. All rights reserved.
REF
T/H
AD7298-1
BUF
Figure 1.
APPROXIMATION
SUCCESSIVE
SEQUENCER
CONTROL
10-BIT
LOGIC
ADC
AD7298-1
GND
www.analog.com
SCLK
DOUT
DIN
CS
V
DRIVE

Related parts for AD7298-1

AD7298-1 Summary of contents

Page 1

... High speed serial interface SPI 20-lead LFCSP GENERAL DESCRIPTION The AD7298 10-bit, high speed, low power, 8-channel, successive approximation ADC. The part operates from a single 3.3 V power supply and features throughput rates MSPS. The device contains a low noise, wide bandwidth track-and-hold amplifier that can handle input frequencies in excess of 30 MHz ...

Page 2

... Changes to Figure 22 ...................................................................... 14 10/10—Revision 0: Initial Version Analog Input ............................................................................... 13 V ............................................................................................ 14 DRIVE The Internal or External Reference .......................................... 14 Control Register .............................................................................. 15 Modes of Operation ....................................................................... 16 Traditional Multichannel Mode of Operation ........................ 16 Repeat Operation ....................................................................... 17 Power-Down Modes .................................................................. 18 Powering Up the AD7298-1 ...................................................... 19 Reset ............................................................................................. 19 Serial Interface ................................................................................ 20 Layout and Configuration ............................................................. 21 Outline Dimensions ....................................................................... 22 Ordering Guide .......................................................................... 22 Rev Page ...

Page 3

... V DRIVE 0.3 × V DRIVE ±0.01 ±1 3 Rev Page AD7298-1 = 2.5 V internal −40°C to +125°C, unless A Unit Test Conditions/Comments kHz sine wave 40.1 kHz 41.5 kHz kHz, f ...

Page 4

... AD7298-1 Parameter LOGIC OUTPUTS Output High Voltage Output Low Voltage Floating State Leakage Current 3 Floating State Output Capacitance CONVERSION RATE Conversion Time Track-and-Hold Acquisition Time 2, 3 Throughput Rate POWER REQUIREMENTS DRIVE 5 I TOTAL Normal Mode (Operational) Normal Mode (Static) ...

Page 5

... SCLK falling edge to DOUT high impedance DIN setup time prior to SCLK falling edge DIN hold time after SCLK falling edge Delay from CS rising edge to DOUT high impedance Internal reference power-up time from full power-down Rev Page AD7298-1 ) and timed from a voltage level DRIVE = 20 MHz SCLK ...

Page 6

... AD7298-1 ABSOLUTE MAXIMUM RATINGS Table 3. Parameter V to GND, GND1 GND, GND1 DRIVE Analog Input Voltage to GND1 Digital Input Voltage to GND Digital Output Voltage to GND V to GND1 REF AGND to GND Input Current to Any Pin Except Supplies Operating Temperature Range Storage Temperature Range ...

Page 7

... Serial Data Output. The conversion result from the AD7298-1 is provided on this output as a serial data stream. The bits are clocked out on the falling edge of the SCLK input. The data stream from the AD7298-1 consists of four address bits indicating which channel the conversion result corresponds to, followed by the 10 bits of conversion data (MSB first) ...

Page 8

... This pin can be used to reset the device by toggling the pin low for a minimum and a maximum of 100 ns. If the maximum time is exceeded, the part enters power-down mode. When placing the AD7298-1 into full power-down mode, the analog inputs must return ...

Page 9

... V (V) REF Figure 6. INL vs. V REF 0.50 0.40 INL (Positive) 0.30 0.20 0.10 0 –0.10 INL (Negative) –0.20 –0.30 –0.40 –0.50 1.0 1.2 1.4 1.6 1.8 2.0 V (V) REF Figure 7. DNL vs. V REF 0.5 1.0 1.5 EXTERNAL VOLTAGE REFERENCE (V) Figure 8. Effective Number of Bits vs. V AD7298-1 2.2 2.4 2.6 2.2 2.4 2 DRIVE 2.0 2.5 REF ...

Page 10

... AD7298-1 3 DRIVE 2.5 2.0 1.5 1.0 0 0.5 1.0 1.5 2.0 2.5 CURRENT LOAD (mA) Figure 9. V vs. Reference Output Current Drive REF – –92 DRIVE –94 –96 –98 –100 –102 –104 –106 –108 –110 1k 10k 100k 1M RIPPLE FREQUENCY (Hz) Figure 10. PSRR vs. Supply Ripple Frequency Without Supply Decoupling 110 105 ...

Page 11

... DRIVE 10 0 Figure 17. Power vs. Throughput in Normal Mode with V 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 1000 1200 2.8 Figure 18. Full Shutdown Current vs. Supply Voltage for Various Rev Page AD7298 DRIVE 100 200 300 400 500 600 700 800 900 THROUGHPUT (kSPS) V –40°C +85°C DRIVE 0°C +105° ...

Page 12

... N- bit converter with a sine wave input is given by Signal-to-(Noise + Distortion) = (6. 1.76) dB Thus, the SINAD is 61.96 dB for an ideal 10-bit converter. Total Harmonic Distortion (THD) The ratio of the rms sum of harmonics to the fundamental. For the AD7298- defined ...

Page 13

... CIRCUIT INFORMATION The AD7298 high speed, 8-channel, 10-bit ADC. The part can be operated from a 2 3.6 V supply and is capable of throughput rates of 1 MSPS per analog input channel. The AD7298-1 provides the user with an on-chip, track-and-hold ADC and a serial interface housed in a 20-lead LFCSP. The ...

Page 14

... V (see the Absolute Maximum Ratings DD section). THE INTERNAL OR EXTERNAL REFERENCE The AD7298-1 can operate with either the internal 2.5 V on-chip reference or an externally applied reference. The EXT_REF bit in the control register is used to determine whether the internal reference is used. If the EXT_REF bit is selected in the control register, an external reference can be supplied through the V pin ...

Page 15

... This partial power-down mode is selected by writing this bit in the control register. In this mode, some of the internal analog circuitry is powered down. The AD7298-1 retains the information in the control register while in partial power-down mode. The part remains in this mode until written to this bit. ...

Page 16

... FOR CHANNEL 2 NO WRITE TO THE DIN CONTROL REGISTER Figure 24. Configuring a Conversion and Read with the AD7298-1, Numerous Channels Selected for Conversion subsequent (second) CS falling edge; and the third CS falling edge will have the result (V operates with one cycle latency, therefore the conversion result corresponding to each conversion is available one serial read cycle after the cycle in which the conversion was initiated ...

Page 17

... The conversion sequence of the selected channels in the repeat mode of operation continues until the control register of the AD7298-1 is reprogrammed not necessary to write to the control register once a repeat operation is initiated unless a change in the AD7298-1 configuration is required. The WRITE bit ...

Page 18

... Serial Interface section. The data presented to the AD7298-1 on the DIN line during the first 16 clock cycles of the data transfer are loaded into the control register (provided the WRITE bit is 1). The part remains fully powered up in normal mode at the end of the conversion as long as the PPD bit is set the write transfer during that conversion ...

Page 19

... RESET The AD7298-1 includes a reset feature that can be used to reset the device and the contents of all internal registers, including the control register, to their default state. ...

Page 20

... SERIAL INTERFACE Figure 28 shows the detailed timing diagram for the serial interface to the AD7298-1. The serial clock provides the conversion clock and controls the transfer of information to and from the AD7298-1 during each conversion. The CS signal initiates the data transfer and conversion process. ...

Page 21

... The PCB containing the AD7298-1 should have separate analog and digital sections, each having its own area of the board. The AD7298-1 should be located in the analog section on any PCB. Decouple the power supply to the AD7298-1 to ground with 10 µF and 0.1 µF capacitors. Place the capacitors as physically close as possible to the device, with the 0.1 µ ...

Page 22

... AD7298-1 OUTLINE DIMENSIONS PIN 1 INDICATOR 0.80 0.75 0.70 SEATING PLANE ORDERING GUIDE 1 Model Temperature Range AD7298-1BCPZ −40°C to +125°C AD7298-1BCPZ-RL −40°C to +125° RoHS Compliant Part. 4.10 0.30 4.00 SQ 0.25 3.90 0.18 16 0.50 15 BSC EXPOSED PAD 11 10 0.50 TOP VIEW BOTTOM VIEW 0.40 0.30 0.05 MAX 0.02 NOM COPLANARITY 0.08 0.20 REF COMPLIANT TO JEDEC STANDARDS MO-220-WGGD. ...

Page 23

... NOTES Rev Page AD7298-1 ...

Page 24

... AD7298-1 NOTES ©2010–2011 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D09321-0-1/11(A) Rev Page ...

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