2-/4-/8-Channel, 1 MSPS, Ultralow Power, 12-Bit SAR ADC Data Sheet AD7091R-2/AD7091R-4/AD7091R-8 FEATURES FUNCTIONAL BLOCK DIAGRAM REF / IN Ultralow system power REF OUT MUX ADC V REGCAP OUT IN DD Flexible power/throughput rate management Normal mode 2.5V V 0 VREF IN 12-BIT 1.4 mW at 1 MSPS SUCCESSIVE V 1 T/H IN APPROXIMATION Power-down mode ADC V 2 IN V DRIVE 550 nA typical at V = 5.25 V DD V 3 IN I/P 435 nA typical at V = 3 V DD V 4 MUX IN RESET Programmable ALERT interrupt pin (4-/8-channel models) V 5 IN CONVST High performance ON-CHIP V 6 IN OSC SDO 1 MSPS throughput with no latency/pipeline delay V 7 CONTROL LOGIC IN SDI AND REGISTERS SNR: 70 dB typical at 10 kHz input frequency SCLK THD: 80 dB typical at 10 kHz input frequency CS CHANNEL SEQUENCER INL: 0.7 LSB typical, 1.0 LSB maximum AD7091R-8 Small system footprint On-chip accurate 2.5 V reference, 5 ppm/C typical drift GND ALERT/ GPO GND MUX /ADC to allow single buffer amplifier 1 OUT IN BUSY/ GPO 0 Daisy-chain mode 16-lead, 20-lead, and 24-lead 4 mm 4 mm LFCSP packages Figure 1. 16-lead, 20-lead, and 24-lead TSSOP packages GENERAL DESCRIPTION Easy to use The AD7091R-2/AD7091R-4/AD7091R-8 family is a multichannel SPI/QSPI/MICROWIRE/DSP compatible digital interface 12-bit, ultralow power, successive approximation analog-to- Integrated programmable channel sequencer digital converter (ADC) that is available in two, four, or eight BUSY indication available (4-/8-channel models) analog input channel options. The AD7091R-2/AD7091R-4/ Built in features for control and monitoring applications AD7091R-8 operate from a single 2.7 V to 5.25 V power supply GPOx pins available (4-/8-channel models) and are capable of achieving a sampling rate of 1 MSPS. Wide operating range Temperature range: 40C to +125C The AD7091R-2/AD7091R-4/AD7091R-8 family offers up to eight Specified for V of 2.7 V to 5.25 V DD single-ended analog input channels with a channel sequencer that allows a preprogrammed selection of channels to be converted APPLICATIONS sequentially. The AD7091R-2/AD7091R-4/ AD7091R-8 also Battery-powered systems feature an on-chip conversion clock, an on-chip accurate 2.5 V Personal digital assistants reference, and a high speed serial interface. Medical instruments The AD7091R-2/AD7091R-4/AD7091R-8 have a serial port Mobile communications interface (SPI) that allows data to be read after the conversion Instrumentation and control systems while achieving a 1 MSPS throughput rate. The conversion process Data acquisition systems CONVST and data acquisition are controlled using the pin. Optical sensors Diagnostic/monitoring functions The AD7091R-2/AD7091R-4/AD7091R-8 use advanced design techniques to achieve ultralow power dissipation at high throughput rates. They also feature flexible power management options. An on-chip configuration register allows the user to set up different operating conditions. These include power management, alert functionality, busy indication, channel sequencing, and general-purpose output pins. The MUXOUT and ADCIN pins allow signal conditioning of the multiplexer output prior to acquisition by the ADC. 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. 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 20132015 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com 10891-001AD7091R-2/AD7091R-4/AD7091R-8 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Addressing Registers .................................................................. 23 Applications ....................................................................................... 1 Conversion Result Register ....................................................... 24 Functional Block Diagram .............................................................. 1 Channel Register ........................................................................ 25 General Description ......................................................................... 1 Configuration Register .............................................................. 26 Revision History ............................................................................... 2 Alert Indication Register ........................................................... 28 Specifications ..................................................................................... 3 Channel x Low Limit Register .................................................. 30 Timing Specifications .................................................................. 5 Channel x High Limit Register ................................................. 30 Absolute Maximum Ratings ............................................................ 7 Channel x Hysteresis Register .................................................. 30 Thermal Resistance ...................................................................... 7 Serial Port Interface ........................................................................ 31 ESD Caution .................................................................................. 7 Reading Conversion Result ....................................................... 31 Pin Configurations and Function Descriptions ........................... 8 Writing Data to the Registers ................................................... 31 Typical Performance Characteristics ........................................... 13 Reading Data from the Registers.............................................. 31 Terminology .................................................................................... 18 Power-On Device Initialization ................................................ 33 Theory of Operation ...................................................................... 19 Modes of Operation ....................................................................... 34 Circuit Information .................................................................... 19 Normal Mode .............................................................................. 34 Converter Operation .................................................................. 19 Power-Down Mode .................................................................... 34 ADC Transfer Function ............................................................. 19 ALERT (AD7091R-4 and AD7091R-8 Only) .......................... 35 Reference ..................................................................................... 19 BUSY (AD7091R-4 and AD7091R-8 Only) ............................. 35 Power Supply ............................................................................... 20 Channel Sequencer .................................................................... 36 Device Reset ................................................................................ 20 Daisy Chain ................................................................................. 37 Typical Connection Diagram.................................................... 20 Outline Dimensions ....................................................................... 39 Analog Input ............................................................................... 20 Ordering Guide .......................................................................... 42 Driver Amplifier Choice ............................................................ 21 Registers ........................................................................................... 23 REVISION HISTORY 12/15Rev. B to Rev. C Changes to Table 5 ............................................................................. 8 Change to the Reference Section .................................................. 19 Added Figure 8 ..................................................................................9 Changes to Table 6 ............................................................................. 9 11/14Rev. A to Rev. B Added Figure 10 ............................................................................. 11 Added Endnote 1 .............................................................................. 3 Changes to Table 7 .......................................................................... 11 Added Total Power Dissipation (Normal Mode) of 0.080 mW ... 4 Added Power Supply Section and Table 8 Renumbered Changes to Table 2 ............................................................................ 5 Sequentially ..................................................................................... 20 Added Device Reset Section and Figure 43 Renumbered Added Driver Amplifier Choice Section and Table 9 ................ 21 Sequentially ..................................................................................... 20 Changes to Table 16 ....................................................................... 26 Added Power-On Device Initialization Section and Figure 53 .. 33 Changed Serial Interface Section to Serial Port Interface 7/14Rev. 0 to Rev. A Section .............................................................................................. 31 Added 16-Lead LFCSP, 20-Lead LFCSP, and Changes to Figure 52...................................................................... 33 24-Lead LFCSP ................................................................... Universal Updated Outline Dimensions ....................................................... 38 Changes to Features Section............................................................ 1 Changes to Ordering Guide .......................................................... 41 Changes to General Description Section ...................................... 1 Changes to Table 1 ............................................................................ 3 12/13Revision 0: Initial Version Changes to Table 4 ............................................................................ 7 Added Figure 6 Renumbered Sequentially .................................. 8 Rev. C Page 2 of 42