500 kSPS, 4-Channel, Software-Selectable, True Bipolar Input, 12-Bit Plus Sign ADC Data Sheet AD7323 FEATURES FUNCTIONAL BLOCK DIAGRAM V REFIN/OUT V DD CC 12-bit plus sign SAR ADC True bipolar input ranges AD7323 Software-selectable input ranges 2.5V 10 V, 5 V, 2.5 V, 0 V to +10 V V 0 IN VREF 13-BIT V 1 500 kSPS throughput rate IN I/P SUCCESSIVE T/H MUX V 2 APPROXIMATION IN Four analog input channels with channel sequencer ADC V 3 IN Single-ended, true differential, and pseudo differential analog input capability High analog input impedance DOUT Low power: 18 mW SCLK CHANNEL CONTROL LOGIC AND REGISTERS SEQUENCER CS Full power signal bandwidth: 22 MHz DIN Internal 2.5 V reference High speed serial interface V DRIVE Power-down modes AGND V DGND SS 16-lead TSSOP package Figure 1. iCMOS process technology GENERAL DESCRIPTION PRODUCT HIGHLIGHTS 1 The AD7323 is a 4-channel, 12-bit plus sign successive 1. The AD7323 can accept true bipolar analog input signals, approximation analog-to-digital converter (ADC) designed on 10 V, 5 V, and 2.5 V, and 0 V to +10 V unipolar signals. the iCMOS (industrial CMOS) process. iCMOS is a process 2. The four analog inputs can be configured as four single- combining high voltage silicon with submicron CMOS and ended inputs, two true differential input pairs, two pseudo differential inputs, or three pseudo differential inputs. complementary bipolar technologies. It enables the development of a wide range of high performance analog ICs capable of 33 V 3. 500 kSPS serial interface. SPI-/QSPI-/DSP-/MICROWIRE- operation in a footprint that no previous generation of high compatible interface. voltage parts could achieve. Unlike analog ICs using conven- 4. Low power, 18 mW, at a maximum throughput rate of tional CMOS processes, iCMOS components can accept bipolar 500 kSPS. input signals while providing increased performance, dramati- 5. Channel sequencer. cally reduced power consumption, and reduced package size. Table 1. Similar Devices The AD7323 can accept true bipolar analog input signals. The Device Throughput Number of AD7323 has four software selectable input ranges, 10 V, 5 V, Number Rate Number of bits Channels 2.5 V, and 0 V to +10 V. Each analog input channel can be AD7329 1000 kSPS 12-bit plus sign 8 independently programmed to one of the four input ranges. AD7328 1000 kSPS 12-bit plus sign 8 The analog input channels on the AD7323 can be programmed AD7327 500 kSPS 12-bit plus sign 8 to be single-ended, true differential, or pseudo differential. AD7324 1000 kSPS 12-bit plus sign 4 AD7322 1000 kSPS 12-bit plus sign 2 The ADC contains a 2.5 V internal reference. The AD7323 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 AD7323 can accept a true bipolar 12 V analog input. Minimum 12 V VDD and VSS 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 500 kSPS. 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 20062013 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. 05400-001AD7323 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Control Register ......................................................................... 23 Functional Block Diagram .............................................................. 1 Sequence Register ....................................................................... 25 General Description ......................................................................... 1 Range Register ............................................................................ 25 Product Highlights ........................................................................... 1 Sequencer Operation ..................................................................... 26 Revision History ............................................................................... 2 Reference ..................................................................................... 28 Specifications ..................................................................................... 3 V ............................................................................................ 28 DRIVE Timing Specifications .................................................................. 7 Modes of Operation ....................................................................... 29 Absolute Maximum Ratings ............................................................ 8 Normal Mode (PM1 = PM0 = 0) ............................................. 29 ESD Caution .................................................................................. 8 Full Shutdown Mode (PM1 = PM0 = 1) ................................. 29 Pin Configuration and Function Descriptions ............................. 9 Autoshutdown Mode (PM1 = 1, PM0 = 0) ............................. 30 Typical Performance Characteristics ........................................... 10 Autostandby Mode (PM1 = 0, PM0 = 1) ................................ 30 Terminology .................................................................................... 14 Power vs. Throughput Rate ....................................................... 31 Theory of Operation ...................................................................... 16 Serial Interface ................................................................................ 32 Circuit Information .................................................................... 16 Microprocessor Interfacing ........................................................... 33 Converter Operation .................................................................. 16 AD7323 to ADSP-21xx .............................................................. 33 Analog Input Structure .............................................................. 17 AD7323 to ADSP-BF53x ........................................................... 33 Typical Connection Diagram ................................................... 19 Application Hints ........................................................................... 34 Analog Input ............................................................................... 19 Layout and Grounding .............................................................. 34 Driver Amplifier Choice ............................................................ 21 Power Supply Configuration .................................................... 34 Registers ........................................................................................... 22 Outline Dimensions ....................................................................... 35 Addressing Registers .................................................................. 22 Ordering Guide .......................................................................... 35 REVISION HISTORY 12/13Rev. A to Rev. B Changes to Figure 30 ...................................................................... 18 Changes to Circuit Information Section and Table 6 ................ 16 Changes to Figure 33 and Figure 34............................................. 19 Changes to Addressing Registers Section .................................... 22 Changes to Figure 39 ...................................................................... 20 Changes to Power Supply Configuration Section ...................... 34 Changes to Figure 40 and Figure 41............................................. 21 Changes to Autostandby Mode (PM1 = 0, PM0 = 1) Section .. 30 1/10Rev. 0 to Rev. A Changes to Table 14 and Table 15 ................................................ 33 Changes to Features and General Description Sections .............. 1 Added Power Supply Configuration Section .............................. 34 Changes to Power Requirements, Normal Mode (Operational), Added Figure 54 Renumbered Sequentially .............................. 34 I and I Parameter and Power Dissipation, Normal Mode Added Table 16 Renumbered Sequentially ................................ 34 CC DRIVE (Operational) Parameter, Table 2 ................................................... 5 Changes to Ordering Guide .......................................................... 35 Changes to Endnote 1, Table 4 ........................................................ 8 1/06Revision 0: Initial Version Changes to Table 6, Figure 23, and Figure 24 ............................. 16 Changes to Figure 25, Figure 26, and Figure 29 ......................... 17 Rev. B Page 2 of 36