Differential Input, Dual, Simultaneous Sampling, 4.2 MSPS, 14-Bit, SAR ADC Data Sheet AD7357 FEATURES FUNCTIONAL BLOCK DIAGRAM V V DD DRIVE Dual 14-bit SAR ADC AD7357 Simultaneous sampling V Throughput rate: 4.2 MSPS per channel INA+ 14-BIT T/H SUCCESSIVE V SDATA INA A APPROXIMATION Specified for a V of 2.5 V DD ADC REF A Power dissipation: 36 mW at 4.2 MSPS On-chip reference: 2.048 V 0.25%, 6 ppm/C BUF Dual conversion with read SCLK CONTROL REF LOGIC High speed serial interface CS SPI-/QSPI-/MICROWIRE-/DSP-compatible BUF 40C to +125C Y grade operation, 40C to +85C B grade REF B operation 14-BIT SUCCESSIVE V SDATA INB+ B APPROXIMATION 16-lead TSSOP and 18-lead LFCSP packages T/H ADC V INB Qualified for automotive applications AGND AGND REFGND DGND APPLICATIONS Figure 1. Automotive radar Data acquisition systems Motion control I and Q demodulation RFID readers GENERAL DESCRIPTION PRODUCT HIGHLIGHTS 1 The AD7357 is a dual, 14-bit, high speed, low power, successive 1. Two Complete ADC Functions. approximation analog-to-digital converter (ADC) that operates These functions allow simultaneous sampling and conversion from a single 2.5 V power supply and features throughput rates of two channels. The conversion result of both channels up to 4.2 MSPS. The device contains two ADCs, each preceded is simultaneously available on separate data lines or in by a low noise, wide bandwidth track-and-hold circuit that can succession on one data line if only one serial port is available. handle input frequencies in excess of 110 MHz. 2. High Throughput with Low Power Consumption. The AD7357 offers a 4.2 MSPS throughput rate with 36 mW The conversion process and data acquisition use standard control power consumption. inputs allowing for easy interfacing to microprocessors or 3. Simultaneous Sampling. digital signal processors (DSPs). The input signal is sampled on The device features two standard successive approximation the falling edge of CS a conversion is also initiated at this point. CS ADCs with accurate control of the sampling instant via a The conversion time is determined by the SCLK frequency. input and once off conversion control. The AD7357 uses advanced design techniques to achieve very low power dissipation at high throughput rates. With a 2.5 V Table 1. Related Devices supply and a 4.2 MSPS throughput rate, the device consumes Generic Resolution Throughput Analog Input 14 mA typically. The device also offers flexible power and AD7356 12-bit 5 MSPS Differential throughput rate management options. AD7352 12-bit 3 MSPS Differential The analog input range for the device is the differential common AD7266 12-bit 2 MSPS Differential/single- mode VREF/2. The AD7357 has an on-chip 2.048 V reference ended that can be overdriven when an external reference is preferred. AD7866 12-bit 1 MSPS Single-ended The AD7357 is available in a 16-lead thin shrink small outline AD7366 12-bit 1 MSPS Single-ended bipolar package (TSSOP) and an 18-lead lead frame chip scale package AD7367 14-bit 1 MSPS Single-ended bipolar (LFCSP). 1 Protected by U.S. Patent No. 6,681,332. Rev. E 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 20092015 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 07757-001AD7357 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Driving Differential Inputs ....................................................... 16 Applications ....................................................................................... 1 Voltage Reference ....................................................................... 17 Functional Block Diagram .............................................................. 1 ADC Transfer Function ............................................................. 17 General Description ......................................................................... 1 Modes of Operation ....................................................................... 18 Product Highlights ........................................................................... 1 Normal Mode .............................................................................. 18 Revision History ............................................................................... 2 Partial Power-Down Mode ....................................................... 18 Specifications ..................................................................................... 3 Full Power-Down Mode ............................................................ 19 Timing Specifications .................................................................. 6 Power-Up Times ......................................................................... 20 Absolute Maximum Ratings ............................................................ 7 Power vs. Throughput Rate ....................................................... 20 ESD Caution .................................................................................. 7 Serial Interface ................................................................................ 21 Pin Configurations and Function Descriptions ........................... 8 Application Suggestions................................................................. 22 Typical Performance Characteristics ........................................... 10 Grounding and Layout .............................................................. 22 Terminology .................................................................................... 12 Evaluating the AD7357 Performance ...................................... 22 Theory of Operation ...................................................................... 14 Outline Dimensions ....................................................................... 23 Circuit Information .................................................................... 14 Ordering Guide .......................................................................... 24 Converter Operation .................................................................. 14 Automotive Products ................................................................. 24 Analog Input Structure .............................................................. 14 Analog Inputs .............................................................................. 16 REVISION HISTORY 12/15Rev. D to Rev. E 2/11Rev. 0 to Rev. A Changes to Figure 3 and Table 5 ..................................................... 8 Changes to Features and Applications Sections ............................ 1 Changes to Table 2 ............................................................................. 3 10/15Rev. C to Rev. D Added AD7357WY Temperature Range to Endnote 1 in Table 3 .... 5 Changes to Figure 20 ...................................................................... 16 Changes to SDATA , SDATA Pin Description ............................ 7 B A Changes to Figure 20 and Figure 22 ............................................ 14 6/15Rev. B to Rev. C Changes to Figure 31 ...................................................................... 18 Added 18-Lead LFCSP ....................................................... Universal Changes to Ordering Guide .......................................................... 20 Change to Features Section ............................................................. 1 Added Automotive Products Section .......................................... 20 Changes to Table 2 ............................................................................ 5 Added Figure 3, Renumbered Sequentially .................................. 8 4/09Revision 0: Initial Version Change to Circuit Information Section ....................................... 13 Updated Outline Dimensions ....................................................... 22 Changes to Ordering Guide .......................................................... 22 8/11Rev. A to Rev. B Changes to Midscale Error Match Parameter, Table 2 ................ 3 Changes to Figure 21 and Figure 22 ............................................. 14 Added Voltage Reference Section ......................................................... 14 Rev. E Page 2 of 24