2 2-Channel, 12-Bit ADC with I C-Compatible Interface in 10-Lead MSOP AD7992 FUNCTIONAL BLOCK DIAGRAM FEATURES GND CONVST 12-bit ADC with fast conversion time: 2 s typ 2 single-ended analog input channels AD7992 Specified for V of 2.7 V to 5.5 V DD V 1 12-BIT SUCCESSIVE IN CONTROL I/P T/H APPROXIMATION LOGIC MUX Low power consumption V 2/REF IN IN ADC Fast throughput rate: up to 188 kSPS VIN2/REFIN V DD SOFTWARE Sequencer operation CONTROL DATA LIMIT HIGH Temperature range: 40 C to 125 C REGISTER CH1 CONVERSION HYSTERESIS RESULT Automatic cycle mode REGISTER CH0 REGISTER DATA LIMIT 2 LOW I C-compatible serial interface supports standard, fast, REGISTER CH1 CONFIGURATION ALERT REGISTER and high speed modes DATA LIMIT HIGH ALERT STATUS Out-of-range indicator/alert function REGISTER CH2 REGISTER HYSTERESIS Pin-selectable addressing via AS REGISTER CH1 DATA LIMIT LOW CYCLE TIMER 2 2 versions allow 5 I C addresses REGISTER CH2 REGISTER AS SCL Shutdown mode: 1 A max 2 I C INTERFACE SDA 10-lead MSOP package GND GENERAL DESCRIPTION Figure 1. The AD7992 is a 12-bit, low power, successive approximation 2 ADC with an I C-compatible interface. The part operates from PRODUCT HIGHLIGHTS a single 2.7 V to 5.5 V power supply and features a 2 s conver- 1. 2 s conversion time and low power consumption. sion time. The part contains a 2-channel multiplexer and track- 2 2. I C-compatible serial interface with pin-selectable and-hold amplifier that can handle input frequencies up to addresses. Two AD7992 versions allow five AD7992 11 MHz. devices to be connected to the same serial bus. The AD7992 provides a 2-wire serial interface compatible with 3. The part features automatic shutdown while not converting 2 I C interfaces. The part comes in two versions, the AD7992-0 to maximize power efficiency. Current consumption is and the AD7992-1, and each version allows for at least two 1 A max when in shutdown mode at 3 V. 2 different I C addresses. The AD7992-0 supports standard and 4. Reference can be driven up to the power supply. 2 fast I C interface modes, and the AD7992-1 supports standard, 2 5. Out-of-range indicator that can be software disabled or fast, and high speed I C interface modes. enabled. The AD7992 normally remains in a shutdown state while not 6. One-shot and automatic conversion rates. converting, and powers up only for conversions. The conversion process can be controlled using the CONVST pin, by a 7. Registers store minimum and maximum conversion 2 results. command mode where conversions occur across I C write operations, or an automatic conversion interval mode selected Table 1. Related Products through software control. Part Number No. of Bits No. of Channels Package The AD7992 requires an external reference in the range of 1.2 V AD7998 12 8 20-TSSOP to VDD. This allows the widest dynamic input range to the ADC. AD7994 12 4 16-TSSOP On-chip limit registers can be programmed with high and low AD7997 10 8 20-TSSOP limits for the conversion result, and an open-drain, out-of- AD7993 10 4 16-TSSOP range indicator output (ALERT) becomes active when the conversion result violates the programmed high or low limits. This output can be used as an interrupt. Rev. 0 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 rights of third parties that may result from its use. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Specifications subject to change without notice. No license is granted by implication Tel: 781.329.4700 www.analog.com or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Fax: 781.326.8703 2005 Analog Devices, Inc. All rights reserved. 03263-0-001AD7992 TABLE OF CONTENTS Specifications..................................................................................... 3 Serial Interface ................................................................................ 20 2 I C Timing Specifications................................................................ 5 Serial Bus Address...................................................................... 20 Absolute Maximum Ratings............................................................ 7 Writing to the AD7992 .................................................................. 21 ESD Caution.................................................................................. 7 Writing to the Address Pointer Register for a Subsequent Read.............................................................................................. 21 Pin Configuration and Pin Function Descriptions...................... 8 Writing a Single Byte of Data to the Alert Status Register, Terminology ...................................................................................... 9 Cycle Register, or Configuration Register............................... 21 Typical Performance Characteristics ........................................... 10 Writing Two Bytes of Data to a Limit Register or Hysteresis Register ........................................................................................ 22 Circuit Information........................................................................ 13 Reading Data from the AD7992................................................... 23 Converter Operation.................................................................. 13 ALERT/BUSY Pin .......................................................................... 24 Typical Connection Diagram ................................................... 14 SMBus ALERT............................................................................ 24 Analog Input ............................................................................... 14 Placing the AD7992-1 into High Speed Mode....................... 24 Internal Register Structure ............................................................ 16 The Address Select (AS) Pin..................................................... 24 Address Pointer Register ........................................................... 16 Modes of Operation ....................................................................... 25 Configuration Register .............................................................. 17 Mode 1Using the CONVST Pin ........................................... 25 Conversion Result Register ....................................................... 18 Mode 2 Command mode....................................................... 26 Limit Registers ............................................................................ 18 Mode 3Automatic Cycle Mode............................................. 27 Alert Status Register................................................................... 19 Outline Dimensions ....................................................................... 28 Cycle Timer Register.................................................................. 19 Ordering Guide .......................................................................... 28 Sample Delay and Bit Trial Delay............................................. 19 REVISION HISTORY 1/05Revision 0: Initial Version Rev. 0 Page 2 of 28