1 MSPS,12-Bit ADCs Data Sheet AD7475/AD7495 FEATURES FUNCTIONAL BLOCK DIAGRAM V DD Fast throughput rate: 1 MSPS Specified for VDD of 2.7 V to 5.25 V 12-BIT V T/H IN SUCCESSIVE Low power APPROXIMATION REF IN ADC 4.5 mW max at 1 MSPS with 3 V supplies 10.5 mW max at 1 MSPS with 5 V supplies SCLK Wide input bandwidth: 68 dB SNR at 300 kHz input frequency CONTROL SDATA LOGIC Flexible power/serial clock speed management CS No pipeline delays V DRIVE AD7475 High speed serial interface SPI-/QSPI-/MICROWIRE-/DSP-compatible GND On-board reference: 2.5 V (AD7495 only) V DD Standby mode: 1 A max 12-BIT T/H 8-lead MSOP and SOIC packages V IN SUCCESSIVE APPROXIMATION ADC APPLICATIONS REF OUT BUF Battery-powered systems SCLK Personal digital assistants CONTROL SDATA LOGIC 2.5V Medical instruments REFERENCE CS Mobile communications V DRIVE AD7495 Instrumentation and control systems GND Data acquisition systems Optical sensors Figure 1. GENERAL DESCRIPTION PRODUCT HIGHLIGHTS 1 The AD7475/AD7495 are 12-bit, high speed, low power, 1. The AD7475 offers 1 MSPS throughput rates with 4.5 mW successive-approximation ADCs that operate from a single power consumption. 2.7 V to 5.25 V power supply with throughput rates up to 1 MSPS. 2. Single-supply operation with VDRIVE function. The They contain a low noise, wide bandwidth track-and-hold AD7475/AD7495 operate from a single 2.7 V to 5.25 V amplifier that can handle input frequencies above 1 MHz. supply. The V function allows the serial interface to DRIVE The conversion process and data acquisition are controlled connect directly to either 3 V or 5 V processor systems using CS and the serial clock, allowing the devices to interface independent of V . DD with microprocessors or DSPs. The input signal is sampled on 3. Flexible power/serial clock speed management. The the falling edge of and conversion is initiated at this point. CS conversion rate is determined by the serial clock, allowing The conversion time is determined by the SCLK frequency. the conversion time to be reduced through the serial clock There are no pipeline delays associated with the device. speed increase. The devices also feature shutdown modes The AD7475/AD7495 use advanced design techniques to to maximize power efficiency at lower throughput rates. achieve very low power dissipation at high throughput rates. This allows the average power consumption to reduce while With 3 V supplies and a 1 MSPS throughput rate, the AD7475 not converting. Power consumption is 1 A when in full shutdown. consumes just 1.5 mA, while the AD7495 consumes 2 mA. With 5 V supplies and 1 MSPS, the current consumption is 2.1 mA 4. No pipeline delay. The devices feature a standard successive for the AD7475 and 2.6 mA for the AD7495. approximation ADC with accurate control of the sampling The analog input range for the devices is 0 V to REF IN. The instant via a CS input and once-off conversion control. 2.5 V reference for the AD7475 is applied externally to the REF IN pin, while the AD7495 has an on-board 2.5 V reference. 1 Protected by U.S. Patent No. 6,681,332 Rev. D 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 2018 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com 01684-B-001AD7475/AD7495 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Converter Operation .................................................................. 13 Applications ....................................................................................... 1 ADC Transfer Function ............................................................. 13 General Description ......................................................................... 1 Typical Connection Diagram ................................................... 14 Functional Block Diagram .............................................................. 1 Operating Modes ............................................................................ 16 Product Highlights ........................................................................... 1 Normal Mode .............................................................................. 16 Revision History ............................................................................... 2 Partial Power-Down Mode ....................................................... 16 AD7475 Specifications ..................................................................... 3 Full Power-Down Mode ............................................................ 17 AD7495 Specifications ..................................................................... 5 Power vs. Throughput Rate ....................................................... 19 Timing Specifications ....................................................................... 7 Serial Interface ................................................................................ 20 Timing Example 1 ........................................................................ 8 Microprocessor Interfacing ........................................................... 21 Timing Example 2 ........................................................................ 8 AD7475/AD7495 to TMS320C5X/C54X ................................. 21 Absolute Maximum Ratings ............................................................ 9 AD7475/AD7495 to ADSP-21xx .............................................. 21 ESD Caution .................................................................................. 9 AD7475/AD7495 to DSP56XXX ............................................... 22 Pin Configurations and Function Descriptions ......................... 10 AD7475/AD7495 to MC68HC16 ............................................. 22 Terminology .................................................................................... 11 Outline Dimensions ....................................................................... 23 Typical Performance Characteristics ........................................... 12 Ordering Guide .......................................................................... 24 Theory of Operation ...................................................................... 13 REVISION HISTORY 7/2018Rev. C to Rev. D Changes to Ordering Guide .......................................................... 24 7/2015Rev. B to Rev. C Changes to Ordering Guide .......................................................... 24 5/2005Rev. A to Rev. B Updated Format .................................................................. Universal Added Patent Information............................................................... 1 Updated Outline Dimensions ....................................................... 23 Changes to Ordering Guide .......................................................... 24 Rev. D Page 2 of 24