2.7 V to 5.25 V, Micropower, 2-Channel, 125 kSPS, 12-Bit ADC in 8-Lead MSOP 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 BUF DD CONTROL APPLICATIONS LATCH Battery-powered systems (personal digital assistants, GND CHARGE medical instruments, mobile communications) REDISTRIBUTION DAC 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 a result, the input voltage range on both the AIN0 and AIN1 converter (ADC) that operates from a single 2.7 V to 5.25 V inputs is 0 to VDD. power supply. The AD7887 is capable of 125 kSPS throughput CMOS construction ensures low power dissipation of typically rate. The input track-and-hold acquires a signal in 500 ns and 2 mW for normal operation and 3 W in power-down mode. features a single-ended sampling scheme. The output coding for The part is available in an 8-lead, 0.15-inch-wide narrow body the AD7887 is straight binary, and the part is capable of SOIC and an 8-lead MSOP package. converting full power signals of up to 2.5 MHz. PRODUCT HIGHLIGHTS The AD7887 can be configured for either dual- or single-channel 1. Smallest 12-bit dual-/single-channel ADC 8-lead MSOP operation via the on-chip control register. There is a default package. single-channel mode that allows the AD7887 to be operated as a read-only ADC. In single-channel operation, there is one 2. Lowest power 12-bit dual-/single-channel ADC. analog input (AIN0) and the AIN1/V pin assumes its V REF REF 3. Flexible power management options, including automatic function. This V pin allows the user access to the parts REF power-down after conversion. internal 2.5 V reference, or the V pin can be overdriven by an REF 4. Read-only ADC capability. external reference to provide the reference voltage for the part. This external reference voltage has a range of 2.5 V to VDD. The 5. Analog input range from 0 V to VREF. analog input range on AIN0 is 0 to VREF. 6. Versatile serial input/output port (SPI/QSPI/MICROWIRE/ In dual-channel operation, the AIN1/VREF pin assumes its AIN1 DSP compatible). function, providing a second analog input channel. In this case, the reference voltage for the part is provided via the V pin. As DD Rev. D 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 www.analog.com license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Fax: 781.461.3113 2009 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. 06191-001AD7887 TABLE OF CONTENTS Features .............................................................................................. 1 Theory of Operation ...................................................................... 11 Applications ....................................................................................... 1 Circuit Information .................................................................... 11 Functional Block Diagram .............................................................. 1 Converter Operation .................................................................. 11 General Description ......................................................................... 1 ADC Transfer Function ............................................................. 11 Product Highlights ........................................................................... 1 Typical Connection Diagram ................................................... 11 Revision History ............................................................................... 2 Analog Input ............................................................................... 12 Specif icat ions ..................................................................................... 3 Power-Down Options ................................................................ 13 Timing Specifications .................................................................. 5 Power vs. Throughput Rate ....................................................... 13 Absolute Maximum Ratings ............................................................ 6 Modes of Operation ................................................................... 13 ESD Caution .................................................................................. 6 Serial Interface ............................................................................ 17 Pin Configurations and Function Descriptions ........................... 7 Microprocessor Interfacing ....................................................... 18 Typical Performance Characteristics ............................................. 8 Application Hints ....................................................................... 20 Terminology ...................................................................................... 9 Outline Dimensions ....................................................................... 21 Control Register .............................................................................. 10 Ordering Guide .......................................................................... 21 REVISION HISTORY 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. D Page 2 of 24