EVAL-AD7441CBZ Analog Devices Inc, EVAL-AD7441CBZ Datasheet

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EVAL-AD7441CBZ

Manufacturer Part Number
EVAL-AD7441CBZ
Description
Manufacturer
Analog Devices Inc
Datasheet
1.EVAL-AD7441CBZ.pdf (24 pages)

Specifications of EVAL-AD7441CBZ

Lead Free Status / Rohs Status
Supplier Unconfirmed
FEATURES
Fast throughput rate: 1 MSPS
Specified for V
Low power at maximum throughput rate:
Pseudo differential analog input
Wide input bandwidth:
Flexible power/serial clock speed management
No pipeline delays
High speed serial interface:
Power-down mode: 1 μA maximum
8-lead SOT-23 and MSOP packages
APPLICATIONS
Transducer interface
Battery-powered systems
Data acquisition systems
Portable instrumentation
GENERAL DESCRIPTION
The AD7441/AD7451
low power, single-supply, successive approximation (SAR),
analog-to-digital converters (ADCs) that feature a pseudo
differential analog input. These parts operate from a single
2.7 V to 5.25 V power supply and achieve very low power
dissipation at high throughput rates of up to 1 MSPS.
The AD7441/AD7451 contain a low noise, wide bandwidth,
differential track-and-hold (T/H) amplifier that handles input
frequencies up to 3.5 MHz. The reference voltage for these
devices is applied externally to the V
100 mV to V
the application.
The conversion process and data acquisition are controlled
using CS and the serial clock, allowing the device to interface
with microprocessors or DSPs. The input signals are sampled
on the falling edge of CS when the conversion is initiated.
The SAR architecture of these parts ensures that there are no
pipeline delays.
1
Rev. C
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.
Protected by U.S. Patent Number 6,681,332.
SPI®-/QSPI™-/MICROWIRE™-/DSP-compatible
4 mW maximum at 1 MSPS with V
9.25 mW maximum at 1 MSPS with V
70 dB SINAD at 100 kHz input frequency
DD
, depending on the power supply and what suits
DD
of 2.7 V to 5.25 V
1
are, respectively, 10-/12-bit high speed,
REF
DD
pin and can range from
= 3 V
DD
= 5 V
10-/12-Bit ADCs in an 8-Lead SOT-23
Pseudo Differential Input, 1 MSPS,
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.
4.
5.
6.
7.
8.
V
V
V
REF
IN+
IN–
Operation with 2.7 V to 5.25 V Power Supplies.
High Throughput with Low Power Consumption.
With a 3 V supply, the AD7441/AD7451 offer 4 mW maxi-
mum power consumption for a 1 MSPS throughput rate.
Pseudo Differential Analog Input.
Flexible Power/Serial Clock Speed Management.
The conversion rate is determined by the serial clock,
allowing the power to be reduced as the conversion time
is reduced through the serial clock speed increase. These
parts also feature a shutdown mode to maximize power
efficiency at lower throughput rates.
Variable Voltage Reference Input.
No Pipeline Delays.
Accurate Control of Sampling Instant via CS Input and
Once-Off Conversion Control.
ENOB > 10 Bits Typically with 500 mV Reference.
AD7441/AD7451
FUNCTIONAL BLOCK DIAGRAM
GND
V
DD
©2003–2007 Analog Devices, Inc. All rights reserved.
T/H
Figure 1.
AD7441/AD7451
APPROXIMATION
CONTROL LOGIC
SUCCESSIVE
12-BIT
ADC
www.analog.com
SCLK
SDATA
CS

EVAL-AD7441CBZ Summary of contents

Page 1

FEATURES Fast throughput rate: 1 MSPS Specified for Low power at maximum throughput rate maximum at 1 MSPS with V DD 9.25 mW maximum at 1 MSPS with V Pseudo ...

Page 2

... Reference ..................................................................................... 15 Serial Interface ............................................................................ 16 Modes of Operation ....................................................................... 18 Normal Mode.............................................................................. 18 Power-Down Mode.................................................................... 18 Power vs. Throughput Rate....................................................... 20 Microprocessor and DSP Interfacing ...................................... 20 Grounding and Layout Hints.................................................... 22 Evaluating Performance ............................................................ 22 Outline Dimensions ....................................................................... 23 Ordering Guide .......................................................................... 24 2/04—Rev Rev. A Updated Format.....................................................................Universal Changes to General Description ....................................................... 1 Changes to Table 1 Footnotes ............................................................ 4 Changes to Table 2 Footnotes ............................................................ 6 Changes to Table 3 Footnotes ...

Page 3

SPECIFICATIONS MHz SCLK versions: −40°C to +85°C. Table 1. AD7451 Parameter DYNAMIC PERFORMANCE 1 Signal-to-Noise Ratio (SNR) Signal-to-(Noise + Distortion) (SINAD) 1 Total Harmonic Distortion (THD) 1 Peak ...

Page 4

AD7441/AD7451 Parameter CONVERSION RATE Conversion Time 1 Track-and-Hold Acquisition Time Throughput Rate POWER REQUIREMENTS Normal Mode (Static) Normal Mode (Operational) Full Power-Down Mode Power Dissipation Normal Mode (Operational) Full Power-Down 1 See Terminology section. ...

Page 5

MHz SCLK B version: −40°C to +85°C. Table 2. AD7441 Parameter DYNAMIC PERFORMANCE Signal-to-(Noise + Distortion) (SINAD) 1 Total Harmonic Distortion (THD) 1 Peak Harmonic or Spurious Noise ...

Page 6

AD7441/AD7451 Parameter CONVERSION RATE Conversion Time 1 Track-and-Hold Acquisition Time Throughput Rate POWER REQUIREMENTS Normal Mode (Static) Normal Mode (Operational) Full Power-Down Mode Power Dissipation Normal Mode (Operational) Full Power-Down 1 See the Terminology ...

Page 7

TIMING SPECIFICATIONS MHz SCLK Table 3. Parameter Limit Unit MIN MAX kHz min SCLK 18 MHz max t 16 × ...

Page 8

AD7441/AD7451 ABSOLUTE MAXIMUM RATINGS T = 25°C, unless otherwise noted. A Table 4. Parameter V to GND GND IN GND IN– Digital Input Voltage to GND Digital Output Voltage to GND V to GND REF ...

Page 9

PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS REF AD7441/ V SCLK 2 7 AD7451 IN+ V SDATA 3 6 IN– TOP VIEW (Not to Scale) GND Figure 5. 8-Lead MSOP Pin Configuration Table 5. Pin ...

Page 10

AD7441/AD7451 TYPICAL PERFORMANCE CHARACTERISTICS T = 25° MSPS MHz SCLK 4.75V 3. 2. 100 FREQUENCY (kHz) ...

Page 11

POSITIVE DNL 0.5 0 NEGATIVE DNL –0.5 –1 (V) REF Figure 13. Change in DNL vs. V for V REF POSITIVE DNL ...

Page 12

AD7441/AD7451 TERMINOLOGY Signal-to-(Noise + Distortion) Ratio (SINAD) This is the measured ratio of SINAD at the output of the ADC. The signal is the rms amplitude of the fundamental. Noise is the sum of all nonfundamental signals up to half ...

Page 13

THEORY OF OPERATION CIRCUIT INFORMATION The AD7441/AD7451 are 10-/12-bit, high speed, low power, single-supply, successive approximation, analog-to-digital con- verters (ADCs) with a pseudo differential analog input. These parts operate with a single 2 5.25 V power supply and ...

Page 14

AD7441/AD7451 TYPICAL CONNECTION DIAGRAM Figure 22 shows a typical connection diagram for the device. In this setup, the GND pin is connected to the analog ground plane of the system. The V pin is connected to the AD780, REF a ...

Page 15

When no amplifier is used to drive the analog input recommended that the source impedance be limited to low values. The maximum source impedance depends on the amount of total harmonic distortion that can be tolerated. The THD ...

Page 16

AD7441/AD7451 SERIAL INTERFACE Figure 2 and Figure 3 show detailed timing diagrams for the serial interface of the AD7451 and the AD7441, respectively. The serial clock provides the conversion clock and also controls the transfer of data from the device ...

Page 17

Timing Example 1 Having MHz and a throughput rate of 1 MSPS gives a SCLK cycle time of 1/Throughput = 1/1,000,000 = 1 μs A cycle consists 12.5 (1 ...

Page 18

AD7441/AD7451 MODES OF OPERATION The operating mode of the AD7441/AD7451 is selected by controlling the logic state of the CS signal during a conversion. There are two operating modes: normal mode and power-down mode. The point at which CS is ...

Page 19

PART BEGINS TO POWER SCLK SDATA INVALID DATA brought high before the 10th falling edge of SCLK, the AD7441/AD7451 again go back into power-down. This avoids accidental power-up due to glitches on the ...

Page 20

AD7441/AD7451 POWER VS. THROUGHPUT RATE By using the power-down mode on the device when not con- verting, the average power consumption of the ADC decreases at lower throughput rates. Figure 32 shows how, as the through- put rate is reduced, ...

Page 21

The timer registers, for example, are loaded with a value that provides an interrupt at the required sample interval. When an interrupt is received, a value is transmitted with TFS/DT (ADC control word). The TFS is used to control the ...

Page 22

... PC via the evaluation board controller. The evaluation board controller can be used in conjunction with the AD7441 and the AD7451 evaluation boards, as well as with many other Analog Devices, Inc. evaluation boards ending with the CB designator, to demonstrate and evaluate the ac and dc performance of the AD7441 and the AD7451 ...

Page 23

OUTLINE DIMENSIONS INDICATOR 0.15 MAX 2.90 BSC 1.60 BSC 2.80 BSC PIN 1 0.65 BSC 1.95 1.30 BSC 1.15 0.90 1.45 MAX 0.22 0.08 0.38 SEATING 0.22 PLANE COMPLIANT TO JEDEC STANDARDS ...

Page 24

... This can be used as a standalone evaluation board or in conjunction with the evaluation board controller for evaluation/demonstration purposes. 4 The evaluation board controller is a complete unit allowing control and communicate with all Analog Devices evaluation boards ending in the CB designators. To order a complete evaluation kit, you must order the ADC evaluation board (EVAL-AD7451CB or EVAL-AD7441CB), the EVAL-CONTROL BRD2, and transformer. See the AD7451/AD7441 application note that accompanies the evaluation kit for more information. © ...