2.35 V to 5.25 V, 1 MSPS, 12-/10-/8-Bit ADCs in 6-Lead SC70 AD7476A/AD7477A/AD7478A FEATURES FUNCTIONAL BLOCK DIAGRAM Fast throughput rate: 1 MSPS V DD Specified for VDD of 2.35 V to 5.25 V Low power 12-/10-/8-BIT 3.6 mW at 1 MSPS with 3 V supplies SUCCESSIVE- V T/H IN APPROXIMATION 12.5 mW at 1 MSPS with 5 V supplies ADC Wide input bandwidth 71 dB SNR at 100 kHz input frequency SCLK Flexible power/serial clock speed management CONTROL SDATA No pipeline delays LOGIC CS High speed serial interface SPI/QSPI/MICROWIRE/DSP compatible AD7476A/AD7477A/AD7478A Standby mode: 1 A maximum GND 6-lead SC70 package 8-lead MSOP package Figure 1. Qualified for automotive applications 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 The AD7476A/AD7477A/AD7478A are 12-bit, 10-bit, and 8-bit 1. First 12-/10-/8-bit ADCs in a SC70 package. high speed, low power, successive-approximation analog-to- 2. High throughput with low power consumption. digital converters (ADCs), respectively. The parts operate from a single 2.35 V to 5.25 V power supply and feature throughput 3. Flexible power/serial clock speed management. The rates up to 1 MSPS. The parts contain a low noise, wide conversion rate is determined by the serial clock, allowing bandwidth track-and-hold amplifier that can handle input the conversion time to be reduced through the serial clock frequencies in excess of 13 MHz. The conversion process and speed increase. This allows the average power consumption CS to be reduced when a power-down mode is used while not data acquisition are controlled using and the serial clock, converting. The parts also feature a power-down mode to allowing the devices to interface with microprocessors or DSPs. maximize power efficiency at lower throughput rates. The input signal is sampled on the falling edge of CS, and the Current consumption is 1 A maximum and 50 nA conversion is also initiated at this point. There are no pipeline typically when in power-down mode. delays associated with the parts. The AD7476A/AD7477A/ AD7478A use advanced design techniques to achieve low power 4. Reference derived from the power supply. dissipation at high throughput rates. The reference for the part 5. No pipeline delay. The parts feature a standard successive is taken internally from V to allow the widest dynamic input DD approximation ADC with accurate control of the sampling range to the ADC. Thus, the analog input range for the part is CS instant via a input and once-off conversion control. 0 V to V . The conversion rate is determined by the SCLK. DD 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 20022011 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. 02930-001AD7476A/AD7477A/AD7478A TABLE OF CONTENTS Features .............................................................................................. 1 Typical Connection Diagram ....................................................... 16 Applications ....................................................................................... 1 Analog Input ............................................................................... 16 Functional Block Diagram .............................................................. 1 Digital Inputs .............................................................................. 17 General Description ......................................................................... 1 Modes of Operation ....................................................................... 18 Product Highlights ........................................................................... 1 Normal Mode .............................................................................. 18 Revision History ............................................................................... 2 Power-Down Mode .................................................................... 18 Specifications ..................................................................................... 3 Power-Up Time .......................................................................... 18 AD7476A Specifications .............................................................. 3 Power vs. Throughput Rate ........................................................... 20 AD7477A Specifications .............................................................. 5 Serial Interface ................................................................................ 21 AD7478A Specifications .............................................................. 6 AD7478A in a 12 SCLK Cycle Serial Interface ....................... 22 Timing Specifications .................................................................. 8 Microprocessor Interfacing ........................................................... 23 Absolute Maximum Ratings .......................................................... 10 AD7476A/AD7477A/AD7478A to TMS320C541 Interface 23 ESD Caution ................................................................................ 10 AD7476A/AD7477A/AD7478A to ADSP-218x Interface .... 23 Pin Configurations and Function Descriptions ......................... 11 AD7476A/AD7477A/AD7478A to DSP563xx Interface ...... 24 Typical Performance Characteristics ........................................... 12 Application Hints ........................................................................... 25 Terminology .................................................................................... 14 Grounding and Layout .............................................................. 25 Theory of Operation ...................................................................... 15 Evaluating the AD7476A/AD7477A Performance ............... 25 Circuit Information .................................................................... 15 Outline Dimensions ....................................................................... 26 The Converter Operation .......................................................... 15 Ordering Guide .......................................................................... 26 ADC Transfer Function ............................................................. 15 Automotive Products ................................................................. 27 REVISION HISTORY 1/11Rev. E to Rev. F Changes to Features Section............................................................ 1 Changes to Ordering Guide .......................................................... 26 Added Automotive Products Section .......................................... 27 2/09Rev. D to Rev. E Changes to Features .......................................................................... 1 Changes to Ordering Guide .......................................................... 26 4/06Rev. C to Rev. D Updated Format .................................................................. Universal Changes to Ordering Guide .......................................................... 26 Rev. F Page 2 of 28