8-Channel, 200 kSPS, 12-Bit ADC with Sequencer in 20-Lead TSSOP Data Sheet AD7927 FEATURES FUNCTIONAL BLOCK DIAGRAM AV Fast throughput rate: 200 kSPS DD Specified for AV of 2.7 V to 5.25 V DD REF IN Low power V 0 IN 12-BIT 3.6 mW maximum at 200 kSPS with 3 V supply SUCCESSIVE T/H 7.5 mW maximum at 200 kSPS with 5 V supply APPROXIMATION ADC INPUT 8 (single-ended) inputs with sequencer MUX Wide input bandwidth 70 dB minimum SINAD at 50 kHz input frequency Flexible power/serial clock speed management V 7 IN No pipeline delays SCLK High speed serial interface SPI-, QSPI-, MICROWIRE-, DOUT CONTROL LOGIC SEQUENCER DSP-compatible DIN Shutdown mode: 0.5 A maximum CS 20-lead TSSOP AD7927 V DRIVE Qualified for automotive applications AGND GENERAL DESCRIPTION Figure 1. The AD7927 is a 12-bit, high speed, low power, 8-channel, PRODUCT HIGHLIGHTS successive approximation ADC. The part operates from a 1. High Throughput with Low Power Consumption. single 2.7 V to 5.25 V power supply and features throughput The AD7927 offers up to 200 kSPS throughput rates. At the rates up to 200 kSPS. The part contains a low noise, wide maximum throughput rate with 3 V supplies, the AD7927 bandwidth track-and-hold amplifier that can handle input dissipates 3.6 mW of power maximum. frequencies in excess of 8 MHz. 2. Eight Single-Ended Inputs with a Channel Sequencer. The conversion process and data acquisition are controlled using A consecutive sequence of channels can be selected on CS and the serial clock signal, allowing the device to easily interface which the ADC cycles and converts. with microprocessors or DSPs. The input signal is sampled on the falling edge of CS and the conversion is also initiated at this 3. Single-Supply Operation with VDRIVE Function. point. There are no pipeline delays associated with the part. The AD7927 operates from a single 2.7 V to 5.25 V supply. The VDRIVE function allows the serial interface to connect The AD7927 uses advanced design techniques to achieve directly to either 3 V or 5 V processor systems independent very low power dissipation at maximum throughput rates. At of AV . DD maximum throughput rates, the AD7927 consumes 1.2 mA maximum with 3 V supplies with 5 V supplies, the current 4. Flexible Power/Serial Clock Speed Management. consumption is 1.5 mA maximum. The conversion rate is determined by the serial clock, allowing the conversion time to be reduced through the Through the configuration of the control register, the analog serial clock speed increase. The part also features various input range for the part can be selected as 0 V to REFIN or 0 V shutdown modes to maximize power efficiency at lower to 2 REFIN, with either straight binary or twos complement throughput rates. Current consumption is 0.5 A maxi- output coding. The AD7927 features eight single-ended analog mum when in full shutdown. inputs with a channel sequencer to allow a preprogrammed selection of channels to be converted sequentially. 5. No Pipeline Delay. The part features a standard successive approximation ADC The conversion time for the AD7927 is determined by the CS with a input pin, which allows for accurate control of SCLK frequency, as this is also used as the master clock to each sampling instant. control the conversion. The conversion time may be as short as 800 ns with a 20 MHz SCLK. 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 20032013 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. 03088-001AD7927 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Analog Input Selection .............................................................. 17 General Description ......................................................................... 1 Digital Inputs .............................................................................. 17 Functional Block Diagram .............................................................. 1 VDRIVE ............................................................................................ 18 Product Highlights ........................................................................... 1 The Reference ............................................................................. 18 Revision History ............................................................................... 2 Modes of Operation ....................................................................... 19 Specif icat ions ..................................................................................... 3 Normal Mode (PM1 = PM0 = 1) ............................................. 19 Timing Specifications .................................................................. 5 Full Shutdown (PM1 = 1, PM0 = 0) ........................................ 19 Absolute Maximum Ratings ............................................................ 6 Auto Shutdown (PM1 = 0, PM0 = 1) ....................................... 20 ESD Caution .................................................................................. 6 Powering Up the AD7927 ......................................................... 21 Pin Configuration and Function Descriptions ............................. 7 Power vs. Throughput Rate ....................................................... 21 Terminology ...................................................................................... 8 Serial Interface ................................................................................ 22 Typical Performance Characteristics ........................................... 10 Writing Between Conversions .................................................. 22 Control Register .............................................................................. 12 Microprocessor Interfacing ........................................................... 24 Sequencer Operation ...................................................................... 13 AD7927 to TMS320C541 .......................................................... 24 Shadow Register .............................................................................. 14 AD7927 to ADSP-21xx .............................................................. 24 Circuit Information .................................................................... 15 AD7927 to DSP563xx ................................................................ 25 Converter Operation .................................................................. 15 Application Hints ........................................................................... 26 Analog Input ............................................................................... 15 Grounding and Layout .............................................................. 26 ADC Transfer Function ............................................................. 16 Outline Dimensions ....................................................................... 27 Handling Bipolar Input Signals ................................................ 16 Ordering Guide .......................................................................... 27 Typical Connection Diagram ........................................................ 17 Automotive Products ................................................................. 27 REVISION HISTORY 12/08Rev. A to Rev. B 6/13Rev. C to Rev. D Changes to ESD Parameter, Table 3 ................................................ 6 Deleted Evaluating the AD7927 Performance Section .............. 26 Changes to Ordering Guide .......................................................... 27 Changes to Ordering Guide .......................................................... 27 1/07Rev. 0 to Rev. A 12/11Rev. B to Rev. C Updated Format .................................................................. Universal Changes to Features Section............................................................ 1 Updated Layout ................................................................................. 8 Changes to Table 1 ............................................................................ 3 Updated Layout .............................................................................. 10 Changes to Table 3 ............................................................................ 6 Changes to Figure 12 Caption ...................................................... 14 Changes to Ordering Guide, Added Automotive Products Changes to Figure 13 Caption ...................................................... 15 Section .............................................................................................. 27 Changes to Ordering Guide .......................................................... 27 1/03Revision 0: Initial Version Rev. D Page 2 of 28