Datasheet AD7321 (Analog Devices)

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500 kSPS, 2-Channel, Software-Selectable, True Bipolar Input, 12-Bit Plus Sign ADC Data Sheet AD7321 FEATURES FUNCTIONAL BLOCK DIAGRAM 12-bit plus sign SAR ADC VDD REFIN/OUT VCC True bipolar input ranges AD7321 Software-selectable input ranges ±10 V, ±5 V, ±2.5 V, 0 V to +10 V 2.5V VREF 500 kSPS throughput rate VIN0 13-BIT I/P SUCCESSIVE MUX T/H 2 analog input channels with channel sequencer V APPROXIMATION IN1 ADC Single-ended, true differential, and pseudo differential analog input capability High analog input impedance Low power: 18 mW DOUT CHANNEL CONTROL LOGIC SCLK Full power signal bandwidth: 22 MHz SEQUENCER AND REGISTERS CS Internal 2.5 V reference DIN High speed serial interface VDRIVE Power-down modes
001
14-lead TSSOP package AGND VSS DGND
05399-
i CMOS™ process technology
Figure 1.
GENERAL DESCRIPTION PRODUCT HIGHLIGHTS
The AD73211 is a 2-channel, 12-bit plus sign successive 1. The AD7321 can accept true bipolar analog input signals, approximation ADC designed on the iCMOS (industrial ±10 V, ±5 V, ±2.5 V, and 0 V to +10 V unipolar signals. CMOS) process. iCMOS is a process combining high voltage 2. The two analog inputs are configured as two single-ended silicon with submicron CMOS and complementary bipolar inputs, one true differential input pair, or one pseudo technologies. It enables the development of a wide range of high differential input. performance analog ICs capable of 33 V operation in a footprint that no previous generation of high voltage parts could achieve. 3. A 500 kSPS serial interface. SPI®-/QSPI™-/DSP-/ Unlike analog ICs using conventional CMOS processes, iCMOS MICROWIRE™-compatible interface. components can accept bipolar input signals while providing 4. Low power, 18 mW, at a maximum throughput rate of increased performance, dramatical y reduced power consumption, 500 kSPS. and reduced package size. 5. Channel sequencer. The AD7321 can accept true bipolar analog input signals. The AD7321 has four software-selectable input ranges, ±10 V, ±5 V,
Table 1. Similar Devices
±2.5 V, and 0 V to +10 V. Each analog input channel is indepen-
Device Throughput Number of
dently programmed to one of the four input ranges. The analog
Number Rate Number of bits Channels
input channels on the AD7321 are programmed to be single-ended, AD7329 1000 kSPS 12-bit plus sign 8 true differential, or pseudo differential. AD7328 1000 kSPS 12-bit plus sign 8 AD7327 500 kSPS 12-bit plus sign 8 The ADC contains a 2.5 V internal reference. The AD7321 also AD7324 1000 kSPS 12-bit plus sign 4 al ows for external reference operation. If a 3 V reference is applied AD7323 500 kSPS 12-bit plus sign 4 to the REFIN/OUT pin, the AD7321 can accept a true bipolar AD7322 1000 kSPS 12-bit plus sign 2 ±12 V analog input. A minimum of ±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.
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Document Outline Features Functional Block Diagram General Description Product Highlights Table of Contents Revision History Specifications Timing Specifications Absolute Maximum Ratings ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics Terminology Theory of Operation Circuit Information Converter Operation Output Coding Transfer Functions Analog Input Structure Track-and-Hold Section Typical Connection Diagram Analog Input Single-Ended Inputs True Differential Mode Pseudo Differential Inputs Driver Amplifier Choice Registers Addressing Registers Control Register Range Register Sequencer Operation Reference VDRIVE Modes of Operation Normal Mode Full Shutdown Mode Autoshutdown Mode Autostandby Mode Power vs. Throughput Rate Serial Interface Microprocessor Interfacing AD7321 to ADSP-21xx AD7321 to ADSP-BF53x Application Hints Layout and Grounding Power Supply Configuration Outline Dimensions Ordering Guide