2.35 V to 5.25 V, 1 MSPS, 12-/10-/8-Bit ADCs in 6-Lead SC70 Data Sheet AD7476A/AD7477A/AD7478A FEATURES FUNCTIONAL BLOCK DIAGRAM V Fast throughput rate: 1 MSPS DD Specified for V of 2.35 V to 5.25 V DD Low power 12-/10-/8-BIT 3.6 mW at 1 MSPS with 3 V supplies SUCCESSIVE- V IN T/H APPROXIMATION 12.5 mW at 1 MSPS with 5 V supplies ADC Wide input bandwidth 71 dB SNR at 100 kHz input frequency Flexible power/serial clock speed management SCLK CONTROL No pipeline delays SDATA LOGIC High speed serial interface CS SPI/QSPI/MICROWIRE/DSP compatible AD7476A/AD7477A/AD7478A Standby mode: 1 A maximum 6-lead SC70 package GND 8-lead MSOP 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 3. Flexible power/serial clock speed management. The a single 2.35 V to 5.25 V power supply and feature throughput conversion rate is determined by the serial clock, allowing rates up to 1 MSPS. The parts contain a low noise, wide the conversion time to be reduced through the serial clock bandwidth track-and-hold amplifier that can handle input speed increase. This allows the average power consumption frequencies in excess of 13 MHz. The conversion process and to be reduced when a power-down mode is used while not CS 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/ 4. Reference derived from the power supply. AD7478A use advanced design techniques to achieve low power 5. No pipeline delay. The parts feature a standard successive dissipation at high throughput rates. The reference for the part approximation ADC with accurate control of the sampling is taken internally from V to allow the widest dynamic input DD CS instant via a input and once-off conversion control. range to the ADC. Thus, the analog input range for the part is 0 V to VDD. The conversion rate is determined by the SCLK. Rev. G 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 20022016 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. 02930-001AD7476A/AD7477A/AD7478A Data Sheet 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 ADSP-2181 Interface .... 23 ESD Caution ................................................................................ 10 AD7476A/AD7477A/AD7478A to DSP563xx Interface ...... 24 Pin Configurations and Function Descriptions ......................... 11 Application Hints ........................................................................... 25 Typical Performance Characteristics ........................................... 12 Grounding and Layout .............................................................. 25 Terminology .................................................................................... 14 Outline Dimensions ....................................................................... 26 Theory of Operation ...................................................................... 15 Ordering Guide .......................................................................... 26 Circuit Information .................................................................... 15 Automotive Products ................................................................. 27 The Converter Operation .......................................................... 15 ADC Transfer Function ............................................................. 15 REVISION HISTORY 1/16Rev. F to Rev. G 1/11Rev. E to Rev. F Changes to Table 5 .......................................................................... 10 Changes to Features Section ............................................................ 1 Changed AD7476A/AD7477A/AD7478A to ADSP-218x Changes to Ordering Guide .......................................................... 26 Interface Section to AD7476A/AD7477A/AD7478A to Added Automotive Products Section .......................................... 27 ADSP-2181 Section ........................................................................ 23 Deleted AD7476A/AD7477A/AD7478A to TMS320C541 2/09Rev. D to Rev. E Interface Section and Figure 28 Renumbered Sequentially ..... 23 Changes to Features .......................................................................... 1 Deleted Evaluating the AD7476A/AD7477A Performance Changes to Ordering Guide .......................................................... 26 Section .............................................................................................. 25 Changes to Ordering Guide .......................................................... 26 4/06Rev. C to Rev. D Updated Format .................................................................. Universal Changes to Ordering Guide .......................................................... 26 Rev. G Page 2 of 28