1 MSPS, 12-/10-/8-Bit ADCs in 6-Lead SOT-23 AD7476/AD7477/AD7478 FEATURES FUNCTIONAL BLOCK DIAGRAM Fast throughput rate: 1 MSPS V DD Specified for V of 2.35 V to 5.25 V DD Low power 12-/10-/8-BIT SUCCESSIVE- V 3.6 mW at 1 MSPS with 3 V supplies IN APPROXIMATION ADC 15 mW at 1 MSPS with 5 V supplies Wide input bandwidth 70 dB SNR at 100 kHz input frequency SCLK CONTROL Flexible power/serial clock speed management SDATA LOGIC No pipeline delays CS High speed serial interface AD7476/AD7477/AD7478 SPI-/QSPI-/MICROWIRE-/DSP-compatible Standby mode: 1 A maximum GND 6-lead SOT-23 package Figure 1. APPLICATIONS Battery-powered systems Personal digital assistants Medical instruments Mobile communications Instrumentation and control systems Data acquisition systems High speed modems Optical sensors GENERAL DESCRIPTION PRODUCT HIGHLIGHTS 1 The AD7476/AD7477/AD7478 are, respectively, 12-bit, 10-bit, 1. First 12-/10-/8-Bit ADCs in SOT-23 Packages. and 8-bit, high speed, low power, successive approximation 2. High Throughput with Low Power Consumption. ADCs. The parts operate from a single 2.35 V to 5.25 V power supply and feature throughput rates up to 1 MSPS. Each part 3. Flexible Power/Serial Clock Speed Management. The contains a low noise, wide bandwidth track-and-hold amplifier conversion rate is determined by the serial clock, allowing that can handle input frequencies in excess of 6 MHz. the conversion time to be reduced through the serial clock speed increase. This allows the average power consumption The conversion process and data acquisition are controlled to be reduced while not converting. The parts also feature a CS using and the serial clock, allowing the devices to interface shutdown mode to maximize power efficiency at lower with microprocessors or DSPs. The input signal is sampled on throughput rates. Current consumption is 1 A maximum the falling edge of CS and the conversion is initiated at this when in shutdown mode. point. There are no pipeline delays associated with these parts. 4. Reference Derived from the Power Supply. The AD7476/AD7477/AD7478 use advanced design techniques to achieve very low power dissipation at high throughput rates. 5. No Pipeline Delay. The parts feature a standard successive- The reference for the parts is taken internally from V . This approximation ADC with accurate control of the sampling DD allows the widest dynamic input range to the ADC. Thus, the CS instant via a input and once-off conversion control. analog input range for the parts are 0 V to V . The conversion DD rate is determined by the SCLK. 1 Protected by U.S. Patent No. 6,681,332. Rev. F 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 20002009 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. 01024-001AD7476/AD7477/AD7478 TABLE OF CONTENTS Features .............................................................................................. 1 Typical Performance Characteristics ........................................... 11 Applications ....................................................................................... 1 Terminology .................................................................................... 12 Functional Block Diagram .............................................................. 1 Theory of Operation ...................................................................... 13 General Description ......................................................................... 1 Circuit Information .................................................................... 13 Product Highlights ........................................................................... 1 Converter Operation .................................................................. 13 Revision History ............................................................................... 2 ADC Transfer Function ............................................................. 13 Specif icat ions ..................................................................................... 3 Typical Connection Diagram ................................................... 14 AD7476 Specifications ................................................................. 3 Modes of Operation ................................................................... 15 AD7477 Specifications ................................................................. 5 Power vs. Throughput Rate ....................................................... 17 AD7478 Specifications ................................................................. 7 Serial Interface ............................................................................ 18 Timing Specifications .................................................................. 8 Microprocessor Interfacing ....................................................... 19 Absolute Maximum Ratings ............................................................ 9 Outline Dimensions ....................................................................... 21 ESD Caution .................................................................................. 9 Ordering Guide .......................................................................... 22 Pin Configuration and Function Descriptions ........................... 10 REVISION HISTORY 1/09Rev. E to Rev. F 3/04Rev. C to Rev. D Added U.S. Patent Number .............................................................. 1 Changes to Features .......................................................................... 1 Changes to Specifications ................................................................. 2 Changes to Ordering Guide .......................................................... 22 Changes to Absolute Maximum Ratings ........................................ 6 4/06Rev. D to Rev. E Changes to AD7476/AD7477/AD7478 to ADSP-21xx Updated Format .................................................................. Universal Interface section .............................................................................. 16 Changes to Table 1 Endnotes .......................................................... 3 Changes to Table 2 Endnotes .......................................................... 5 2/03Rev. B to Rev. C Changes to Table 3 Endnotes .......................................................... 7 Changes to General Description ..................................................... 1 Updated Outline Dimensions ....................................................... 21 Changes to Specifications ................................................................. 2 Changes to Ordering Guide .......................................................... 22 Changes to Absolute Maximum Ratings ........................................ 6 Changes to Ordering Guide ............................................................. 6 Changes to Typical Connection Diagram section ..................... 10 Changes to Figure 8 caption .......................................................... 11 Changes to Figure 19 ...................................................................... 16 Changes to Figure 20 ...................................................................... 17 Updated Outline Dimensions ....................................................... 18 Rev. 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