2.7 V to 5.25 V, Micropower, 2-Channel, 125 kSPS, 12-Bit ADC in 8-Lead MSOP Data Sheet AD7887 FEATURES FUNCTIONAL BLOCK DIAGRAM Specified for V of 2.7 V to 5.25 V DD AD7887 AIN0 Flexible power/throughput rate management I/P T/H MUX Shutdown mode: 1 A max AIN1/ One or two single-ended inputs V REF 2.5V Serial interface: SPI/QSPI/MICROWIRE/DSP compatible COMP REF 8-lead narrow SOIC and MSOP packages AIN1/V REF SOFTWARE V Qualified for automotive applications BUF DD CONTROL LATCH APPLICATIONS GND CHARGE Battery-powered systems (personal digital assistants, REDISTRIBUTION DAC medical instruments, mobile communications) Instrumentation and control systems High speed modems SAR + ADC CONTROL LOGIC SPORT DIN CS DOUT SCLK Figure 1. GENERAL DESCRIPTION The AD7887 is a high speed, low power, 12-bit analog-to-digital the reference voltage for the part is provided via the VDD pin. As converter (ADC) that operates from a single 2.7 V to 5.25 V a result, the input voltage range on both the AIN0 and AIN1 power supply. The AD7887 is capable of 125 kSPS throughput inputs is 0 to VDD. rate. The input track-and-hold acquires a signal in 500 ns and CMOS construction ensures low power dissipation of typically features a single-ended sampling scheme. The output coding for 2 mW for normal operation and 3 W in power-down mode. the AD7887 is straight binary, and the part is capable of The part is available in an 8-lead, 0.15-inch-wide narrow body converting full power signals of up to 2.5 MHz. SOIC and an 8-lead MSOP package. The AD7887 can be configured for either dual- or single-channel PRODUCT HIGHLIGHTS operation via the on-chip control register. There is a default 1. Smallest 12-bit dual-/single-channel ADC 8-lead MSOP single-channel mode that allows the AD7887 to be operated as a package. read-only ADC. In single-channel operation, there is one analog input (AIN0) and the AIN1/V pin assumes its V 2. Lowest power 12-bit dual-/single-channel ADC. REF REF function. This V pin allows the user access to the parts REF 3. Flexible power management options, including automatic internal 2.5 V reference, or the V pin can be overdriven by an REF power-down after conversion. external reference to provide the reference voltage for the part. 4. Read-only ADC capability. This external reference voltage has a range of 2.5 V to VDD. The analog input range on AIN0 is 0 to VREF. 5. Analog input range from 0 V to VREF. In dual-channel operation, the AIN1/VREF pin assumes its AIN1 6. Versatile serial input/output port (SPI/QSPI/MICROWIRE/ function, providing a second analog input channel. In this case, DSP compatible). Rev. E 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 19992014 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. 06191-001AD7887 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Circuit Information .................................................................... 11 Applications ....................................................................................... 1 Converter Operation .................................................................. 11 Functional Block Diagram .............................................................. 1 ADC Transfer Function ............................................................. 11 General Description ......................................................................... 1 Typical Connection Diagram ................................................... 11 Product Highlights ........................................................................... 1 Analog Input ............................................................................... 12 Revision History ............................................................................... 2 Power-Down Options ................................................................ 13 Specif icat ions ..................................................................................... 3 Power vs. Throughput Rate ....................................................... 13 Timing Specifications .................................................................. 5 Modes of Operation ................................................................... 13 Absolute Maximum Ratings ............................................................ 6 Serial Interface ............................................................................ 17 ESD Caution .................................................................................. 6 Microprocessor Interfacing ....................................................... 18 Pin Configurations and Function Descriptions ........................... 7 Application Hints ....................................................................... 20 Typical Performance Characteristics ............................................. 8 Outline Dimensions ....................................................................... 21 Terminology ...................................................................................... 9 Ordering Guide .......................................................................... 21 Control Register .............................................................................. 10 Automotive Products ................................................................. 21 Theory of Operation ...................................................................... 11 REVISION HISTORY 9/14Rev. D to Rev. E Changes to Features Section............................................................ 1 Changes to AD7887 to ADSP-21xx Section ............................... 18 Deleted Evaluating the AD7887 Performance Section .............. 20 Updated Outline Dimensions ....................................................... 21 Changes to Ordering Guide .......................................................... 21 Added Automotive Products Section .......................................... 21 2/09Rev. C to Rev. D Changes to Ordering Guide .......................................................... 21 9/06Rev. B to Rev. C Updated Format .................................................................. Universal Change to Absolute Maximum Ratings ......................................... 6 Additions to Pin Configurations .................................................... 7 Added Table 7 .................................................................................. 18 Updated Outline Dimensions ....................................................... 21 Changes to Ordering Guide .......................................................... 21 Rev. E Page 2 of 24