2-Channel, Software-Selectable, True Bipolar Input, 1 MSPS, 12-Bit Plus Sign ADC Data Sheet AD7322 FEATURES FUNCTIONAL BLOCK DIAGRAM V REFIN/OUT V DD CC 12-bit plus sign SAR ADC True bipolar input ranges AD7322 Software-selectable input ranges 10 V, 5 V, 2.5 V, 0 V to +10 V 2.5V VREF V 0 13-BIT IN 1 MSPS throughput rate I/P SUCCESSIVE T/H MUX APPROXIMATION V 1 Two analog input channels with channel sequencer IN ADC Single-ended, true differential, and pseudo differential analog input capability High analog input impedance DOUT Low power: 21 mW CONTROL LOGIC SCLK CHANNEL Full power signal bandwidth: 22 MHz SEQUENCER AND REGISTERS CS Internal 2.5 V reference DIN High speed serial interface V DRIVE Power-down modes 14-lead TSSOP package AGND V DGND SS iCMOS process technology Figure 1. GENERAL DESCRIPTION PRODUCT HIGHLIGHTS 1 The AD7322 is a 2-channel, 12-bit plus sign, successive approx- 1. The AD7322 can accept true bipolar analog input signals, imation analog-to-digital converter (ADC) designed on the 10 V, 5 V, and 2.5 V, and 0 V to +10 V unipolar signals. iCMOS (industrial CMOS) process. iCMOS is a process 2. The two analog inputs can be configured as two single- combining high voltage silicon with submicron CMOS and ended inputs, one true differential input, or one pseudo complementary bipolar technologies. It enables the develop- differential input. ment of a wide range of high performance analog ICs capable of 3. 1 MSPS serial interface. SPI-/QSPI-/DSP-/MICROWIRE- 33 V operation in a footprint that no previous generation of high compatible interface. voltage parts could achieve. Unlike analog ICs using conventional 4. Low power, 31 mW maximum, at 1 MSPS throughput rate. CMOS processes, iCMOS components can accept bipolar input 5. Channel sequencer. signals while providing increased performance, dramatically reduced power consumption, and reduced package size. Table 1. Similar Devices The AD7322 can accept true bipolar analog input signals. The Device Throughput Number of Number Rate Number of bits Channels AD7322 has four software-selectable input ranges, 10 V, 5 V, AD7329 1000 kSPS 12-bit plus sign 8 2.5 V, and 0 V to +10 V. Each analog input channel can be AD7328 1000 kSPS 12-bit plus sign 8 independently programmed to one of the four input ranges. AD7327 500 kSPS 12-bit plus sign 8 The analog input channels on the AD7322 can be programmed AD7324 1000 kSPS 12-bit plus sign 4 to be single-ended, true differential, or pseudo differential. AD7323 500 kSPS 12-bit plus sign 4 The ADC contains a 2.5 V internal reference. The AD7322 also AD7321 500 kSPS 12-bit plus sign 2 allows for external reference operation. If a 3 V reference is applied to the REFIN/OUT pin, the AD7322 can accept a true bipolar 12 V analog input. Minimum 12 V V and V DD SS supplies are required for the 12 V input range. The ADC has a high speed serial interface that can operate at throughput rates up to 1 MSPS. 1 Protected by U.S. Patent No. 6,731,232. Rev. B Document Feedback 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 20052013 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. 04863-001AD7322 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Control Register ......................................................................... 22 Functional Block Diagram .............................................................. 1 Range Register ............................................................................ 24 General Description ......................................................................... 1 Sequencer Operation ..................................................................... 25 Product Highlights ........................................................................... 1 Reference ..................................................................................... 26 Revision History ............................................................................... 2 V ............................................................................................ 26 DRIVE Specifications ..................................................................................... 3 Modes of Operation ....................................................................... 27 Timing Specifications .................................................................. 6 Normal Mode (PM1 = PM0 = 0) ............................................. 27 Absolute Maximum Ratings ............................................................ 7 Full Shutdown Mode (PM1 = PM0 = 1) ................................. 27 ESD Caution .................................................................................. 7 Autoshutdown Mode (PM1 = 1, PM0 = 0) ............................. 28 Pin Configuration and Function Descriptions ............................. 8 Autostandby Mode (PM1 = 0, PM0 = 1) ................................ 28 Typical Performance Characteristics ............................................. 9 Power vs. Throughput Rate ....................................................... 29 Terminology .................................................................................... 13 Serial Interface ................................................................................ 30 Theory of Operation ...................................................................... 15 Microprocessor Interfacing ........................................................... 31 Circuit Information .................................................................... 15 AD7322 to ADSP-21xx .............................................................. 31 Converter Operation .................................................................. 15 AD7322 to ADSP-BF53x ........................................................... 31 Analog Input Structure .............................................................. 16 Application Hints ........................................................................... 32 Typical Connection Diagram ................................................... 18 Layout and Grounding .............................................................. 32 Analog Input ............................................................................... 18 Power Supply Configuration .................................................... 32 Driver Amplifier Choice ............................................................ 20 Outline Dimensions ....................................................................... 33 Registers ........................................................................................... 21 Ordering Guide .......................................................................... 33 Addressing Registers .................................................................. 21 REVISION HISTORY 12/13Rev. A to Rev. B Changes to Figure 30 and Figure 31............................................. 17 Changes to Circuit Information Section and Table 6 ................ 15 Changes to Figure 33 and Figure 34............................................. 18 Changes to Addressing Registers Section .................................... 21 Changes to Figure 39 ...................................................................... 19 Changes to Power Supply Configuration Section ...................... 32 Changes to Figure 40 and Figure 41............................................. 20 Changes to Autostandby Mode (PM1 = 0, PM = 1) Section .... 28 1/10Rev. 0 to Rev. A Changes to Table 14 and Table 15 ................................................ 31 Changes to Power Requirements, Normal Mode (Operational), Added Power Supply Configuration Section .............................. 32 ICC and IDRIVE Parameter and Power Dissipation, Normal Mode Added Table 16 Renumbered Sequentially ................................ 32 Parameter, Table 2 ............................................................................. 5 Added Figure 53 Renumbered Sequentially .............................. 32 Changes to Endnote 1, Table 4 ........................................................ 7 Updated Outline Dimensions ....................................................... 33 Changes to Table 6 .......................................................................... 15 12/05Revision 0: Initial Version Changes to Figure 25 and Figure 26 ............................................. 16 Rev. B Page 2 of 36