4-Channel, 12-/10-/8-Bit ADC with 2 I C-Compatible Interface in 8-Lead SOT-23 Data Sheet AD7991/AD7995/AD7999 FEATURES FUNCTIONAL BLOCK DIAGRAM V DD 12-/10-/8-bit ADCs with fast conversion time: 1 s typical 4 analog input channels/3 analog input channels with reference input V IN0 Specified for V of 2.7 V to 5.5 V 12-/10-/8-BIT DD V I/P IN1 T/H SAR MUX Sequencer operation V ADC IN2 V /V IN3 REF Temperature range: 40C to +125C 2 I C-compatible serial interface supports standard, fast, CONTROL SCL LOGIC AND and high speed modes 2 I C SDA 2 2 versions allow 2 I C addresses INTERFACE Low power consumption Shutdown mode: 1 A maximum AD7991/AD7995/AD7999 8-lead SOT-23 package GND Qualified for automotive applications Figure 1. APPLICATIONS System monitoring Battery-powered systems Data acquisition Medical instruments ADC is 0 V to VDD. An external reference, applied through the GENERAL DESCRIPTION V /V input, can also be used with this part. IN3 REF The AD7991/AD7995/AD7999 are 12-/10-/8-bit, low power, 2 successive approximation ADCs with an I C-compatible interface. PRODUCT HIGHLIGHTS Each part operates from a single 2.7 V to 5.5 V power supply and 1. Four single-ended analog input channels, or three single- features a 1 s conversion time. The track-and-hold amplifier ended analog input channels and one reference input channel. allows each part to handle input frequencies of up to 14 MHz, 2 2. I C-compatible serial interface. Standard, fast, and high and a multiplexer allows taking samples from four channels. speed modes. Each AD7991/AD7995/AD7999 provides a 2-wire serial 3. Automatic shutdown. 2 interface compatible with I C interfaces. The AD7991 and 4. Reference derived from the power supply or external AD7995 come in two versions and each version has an reference. 2 individual I C address. This allows two of the same devices to be 5. 8-lead SOT-23 package. 2 connected to the same I C bus. Both versions support standard, 2 Table 1. Related Devices fast, and high speed I C interface modes. The AD7999 comes in Device Resolution Input Channels one version. AD7998 12 8 The AD7991/AD7995/AD7999 normally remain in a shutdown AD7997 10 8 state, powering up only for conversions. The conversion process AD7994 12 4 2 is controlled by a command mode, during which each I C read AD7993 10 4 operation initiates a conversion and returns the result over the AD7992 12 2 2 I C bus. When four channels are used as analog inputs, the reference for the part is taken from VDD this allows the widest dynamic input range to the ADC. Therefore, the analog input range to the Rev. C 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. 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Technical Support www.analog.com 06461-001AD7991/AD7995/AD7999 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Converter Operation .................................................................. 17 Applications ....................................................................................... 1 Typical Connection Diagram ................................................... 18 Functional Block Diagram .............................................................. 1 Analog Input ............................................................................... 18 General Description ......................................................................... 1 Internal Register Structure ............................................................ 20 Product Highlights ........................................................................... 1 Configuration Register .............................................................. 20 Revision History ............................................................................... 2 Sample Delay and Bit Trial Delay ............................................. 21 Specifications ..................................................................................... 3 Conversion Result Register ....................................................... 21 AD7991 .......................................................................................... 3 Serial Interface ................................................................................ 22 AD7995 .......................................................................................... 5 Serial Bus Address ...................................................................... 22 AD7999 .......................................................................................... 7 Writing to the AD7991/AD7995/AD7999 .................................. 23 2 I C Timing Specifications ............................................................ 9 Reading from the AD7991/AD7995/AD7999 ............................ 24 Absolute Maximum Ratings .......................................................... 11 Placing the AD7991/AD7995/AD7999 into High Speed Mode ................................................................................. 25 ESD Caution ................................................................................ 11 Mode of Operation ......................................................................... 26 Pin Configuration and Function Descriptions ........................... 12 Outline Dimensions ....................................................................... 27 Typical Performance Characteristics ........................................... 13 Ordering Guide .......................................................................... 27 Terminology .................................................................................... 16 Theory of Operation ...................................................................... 17 REVISION HISTORY 7/2018Rev. B to Rev. C Changes to Features Section............................................................ 1 Changes to Table 4 ............................................................................ 7 Changes to Ordering Guide .......................................................... 27 Added Automotive Products Section........................................... 27 10/2010Rev. A to Rev. B Changes to Max Offset Error Parameter in Table 2 ..................... 3 Changes to Max Offset Error Parameter (Y Version) in Table 3 ...... 5 Changes to Max Offset Error Parameter (Y Version) in Table 4 ...... 7 Changes to Ordering Guide ..................................................................... 27 10/2009Rev. 0 to Rev. A Changes to Table 3 ............................................................................ 5 Changes to Table 4 ............................................................................ 7 Updated Ordering Guide ............................................................... 27 12/2007Revision 0: Initial Version Rev. C Page 2 of 27