Pseudo Differential Input, 1 MSPS, 10-/12-Bit ADCs in an 8-Lead SOT-23 AD7441/AD7451 FEATURES FUNCTIONAL BLOCK DIAGRAM V Fast throughput rate: 1 MSPS DD Specified for V of 2.7 V to 5.25 V DD Low power at maximum throughput rate: 4 mW maximum at 1 MSPS with V = 3 V DD V IN+ 12-BIT SUCCESSIVE 9.25 mW maximum at 1 MSPS with V = 5 V T/H DD APPROXIMATION V IN ADC Pseudo differential analog input V REF Wide input bandwidth: 70 dB SINAD at 100 kHz input frequency Flexible power/serial clock speed management No pipeline delays SCLK High speed serial interface: SDATA AD7441/AD7451 CONTROL LOGIC SPI-/QSPI-/MICROWIRE-/DSP-compatible CS Power-down mode: 1 A maximum 8-lead SOT-23 and MSOP packages APPLICATIONS GND Transducer interface Figure 1. Battery-powered systems Data acquisition systems Portable instrumentation PRODUCT HIGHLIGHTS GENERAL DESCRIPTION 1. Operation with 2.7 V to 5.25 V Power Supplies. 1 The AD7441/AD7451 are, respectively, 10-/12-bit high speed, 2. High Throughput with Low Power Consumption. low power, single-supply, successive approximation (SAR), With a 3 V supply, the AD7441/AD7451 offer 4 mW maxi- analog-to-digital converters (ADCs) that feature a pseudo mum power consumption for a 1 MSPS throughput rate. differential analog input. These parts operate from a single 2.7 V to 5.25 V power supply and achieve very low power 3. Pseudo Differential Analog Input. dissipation at high throughput rates of up to 1 MSPS. 4. Flexible Power/Serial Clock Speed Management. The conversion rate is determined by the serial clock, The AD7441/AD7451 contain a low noise, wide bandwidth, allowing the power to be reduced as the conversion time differential track-and-hold (T/H) amplifier that handles input is reduced through the serial clock speed increase. These frequencies up to 3.5 MHz. The reference voltage for these parts also feature a shutdown mode to maximize power devices is applied externally to the VREF pin and can range from efficiency at lower throughput rates. 100 mV to VDD, depending on the power supply and what suits the application. 5. Variable Voltage Reference Input. 6. No Pipeline Delays. The conversion process and data acquisition are controlled CS using and the serial clock, allowing the device to interface CS 7. Accurate Control of Sampling Instant via Input and with microprocessors or DSPs. The input signals are sampled Once-Off Conversion Control. on the falling edge of CS when the conversion is initiated. 8. ENOB > 10 Bits Typically with 500 mV Reference. The SAR architecture of these parts ensures that there are no pipeline delays. 1 Protected by U.S. Patent Number 6,681,332. Rev. D 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 www.analog.com license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Fax: 781.461.3113 20032010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. 03153-001AD7441/AD7451 TABLE OF CONTENTS Features .............................................................................................. 1 ADC Transfer Function ............................................................. 13 Applications ....................................................................................... 1 Typical Connection Diagram ................................................... 14 Functional Block Diagram .............................................................. 1 Analog Input ............................................................................... 14 General Description ......................................................................... 1 Analog Input Structure .............................................................. 14 Product Highlights ........................................................................... 1 Digital Inputs .............................................................................. 15 Revision History ............................................................................... 2 Reference ..................................................................................... 15 Specif icat ions ..................................................................................... 3 Serial Interface ............................................................................ 16 Timing Specifications .................................................................. 7 Modes of Operation ....................................................................... 18 Timing Diagrams .......................................................................... 7 Normal Mode .............................................................................. 18 Absolute Maximum Ratings ............................................................ 8 Power-Down Mode .................................................................... 18 ESD Caution .................................................................................. 8 Power vs. Throughput Rate ....................................................... 20 Pin Configurations and Function Descriptions ........................... 9 Microprocessor and DSP Interfacing ...................................... 20 Typical Performance Characteristics ........................................... 10 Grounding and Layout Hints .................................................... 22 Terminology .................................................................................... 12 Evaluating Performance ............................................................ 22 Theory of Operation ...................................................................... 13 Outline Dimensions ....................................................................... 23 Circuit Information .................................................................... 13 Ordering Guide .......................................................................... 24 Converter Operation .................................................................. 13 REVISION HISTORY 3/10Rev. C to Rev. D 2/04Rev. 0 to Rev. A Changes to IDD Normal Mode (Operational) Parameter .................. 6 Updated Format ..................................................................... Universal Updated Outline Dimensions ............................................................ 23 Changes to General Description ....................................................... 1 Changes to Ordering Guide ............................................................... 24 Changes to Table 1 Footnotes ............................................................ 4 Changes to Table 2 Footnotes ............................................................ 6 3/07Rev. B to Rev. C Changes to Table 3 Footnotes ............................................................ 7 Changes to Table 5 ................................................................................. 9 Changes to Table 5 .............................................................................. 9 Updated Layout .................................................................................... 12 Updated Figures 7, 8, and 9 .............................................................. 13 Changes to Terminology Section....................................................... 12 Changes to Figure 23 ......................................................................... 16 Updated Outline Dimensions ............................................................ 23 Changes to Reference Section .......................................................... 17 Changes to Ordering Guide ............................................................... 24 9/03Revision 0: Initial Version 2/05Rev. A to Rev. B Changes to Ordering Guide ............................................................... 24 Rev. D Page 2 of 24