16-Channel, 1 MSPS, 12-Bit ADC with Sequencer in 28-Lead TSSOP Data Sheet AD7490 FEATURES FUNCTIONAL BLOCK DIAGRAM V DD Fast throughput rate: 1 MSPS Specified for V of 2.7 V to 5.25 V DD AD7490 REF IN Low power at maximum throughput rates 5.4 mW maximum at 870 kSPS with 3 V supplies 12-BIT SUCCESSIVE 12.5 mW maximum at 1 MSPS with 5 V supplies V 0 T/H IN APPROXIMATION ADC 16 (single-ended) inputs with sequencer Wide input bandwidth INPUT MUX 69.5 dB SNR at 50 kHz input frequency Flexible power/serial clock speed management V 15 IN No pipeline delays SCLK High speed serial interface, SPI/QSPI/MICROWIRE/ DOUT CONTROL SEQUENCER LOGIC DSP compatible DIN CS Full shutdown mode: 0.5 A maximum V 28-lead TSSOP and 32-lead LFCSP packages DRIVE AGND Figure 1. GENERAL DESCRIPTION The AD7490 is a 12-bit high speed, low power, 16-channel, frequency because this is also used as the master clock to successive approximation ADC. The part operates from a single control the conversion. 2.7 V to 5.25 V power supply and features throughput rates up The AD7490 is available in a 32-lead LFCSP and a 28-lead to 1 MSPS. The part contains a low noise, wide bandwidth TSSOP package. track-and-hold amplifier that can handle input frequencies in PRODUCT HIGHLIGHTS excess of 1 MHz. 1. The AD7490 offers up to 1 MSPS throughput rates. At The conversion process and data acquisition are controlled maximum throughput with 3 V supplies, the AD7490 using CS and the serial clock signal, allowing the device to dissipates just 5.4 mW of power. easily interface with microprocessors or DSPs. The input signal 2. A sequence of channels can be selected, through which the CS is sampled on the falling edge of , and conversion is also AD7490 cycles and converts. initiated at this point. There are no pipeline delays associated 3. The AD7490 operates from a single 2.7 V to 5.25 V supply. with the part. The VDRIVE function allows the serial interface to connect The AD7490 uses advanced design techniques to achieve very directly to either 3 V or 5 V processor systems independent low power dissipation at high throughput rates. For maximum of V . DD throughput rates, the AD7490 consumes just 1.8 mA with 3 V 4. The conversion rate is determined by the serial clock, supplies, and 2.5 mA with 5 V supplies. allowing the conversion time to be reduced through the serial clock speed increase. The part also features various By setting the relevant bits in the control register, the analog shutdown modes to maximize power efficiency at lower input range for the part can be selected to be a 0 V to REF IN throughput rates. Power consumption is 0.5 A, maximum, input or a 0 V to 2 REF input, with either straight binary IN when in full shutdown. or twos complement output coding. The AD7490 features 16 5. The part features a standard successive approximation single-ended analog inputs with a channel sequencer to allow a CS ADC with accurate control of the sampling instant via a preprogrammed selection of channels to be converted sequen- input and once off conversion control. tially. The conversion time is determined by the 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 20022012 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. 02691-001AD7490 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Shadow Register ......................................................................... 14 Functional Block Diagram .............................................................. 1 Theory of Operation ...................................................................... 16 General Description ......................................................................... 1 Circuit Information .................................................................... 16 Product Highlights ........................................................................... 1 Converter Operation .................................................................. 16 Revision History ............................................................................... 2 ADC Transfer Function ............................................................. 17 Specifications ..................................................................................... 3 Typical Connection Diagram ................................................... 18 Timing Specifications .................................................................. 5 Modes of Operation ................................................................... 19 Absolute Maximum Ratings ............................................................ 6 Serial Interface ............................................................................ 22 ESD Caution .................................................................................. 6 Power vs. Throughput Rate ....................................................... 23 Pin Configurations and Function Descriptions ........................... 7 Microprocessor Interfacing ....................................................... 24 Typical Performance Characteristics ............................................. 8 Application Hints ....................................................................... 25 Terminology .................................................................................... 10 Outline Dimensions ....................................................................... 26 Internal Register Structure ............................................................ 12 Ordering Guide .......................................................................... 27 Control Register .......................................................................... 12 REVISION HISTORY 12/12Rev. C to Rev. D 10/02Rev. 0 to Rev. A Changes to Figure 4 and Table 4 ............................................................. 7 Addition to General Description..................................................... 1 Updated Outline Dimensions (Changed CP-32-2 to CP-32-7) ..... 26 Changes to Timing Specification Notes ......................................... 4 Changes to Ordering Guide ........................................................... 27 Change to Absolute Maximum Ratings ......................................... 5 Addition to Ordering Guide ............................................................ 5 6/09Rev. B to Rev. C Changes to Typical Performance Characteristics .......................... 8 Change to IDD Auto Standby Mode Parameter, Table 1 ............... 4 Added new Figure 9 .......................................................................... 8 5/08Rev. A to Rev. B Changes to Figure 12 and Figure 14............................................. 11 Changes to Figure 20 ...................................................................... 13 Updated Format .................................................................. Universal Changes to Figure 20 to Figure 26 ................................................ 14 Changes to Table 1 ............................................................................ 3 Addition to Analog Input section ................................................ 14 Changes to Figure 12 and Figure 13 ............................................. 14 Change to Figure 29 caption ......................................................... 18 Changes to Figure 14 ...................................................................... 15 Change to Figure 30 to Figure 32 ................................................. 18 Changes to Reference Section ....................................................... 19 Added Application Hints section ................................................. 20 Updated Outline Dimensions ....................................................... 26 Changes to Ordering Guide .......................................................... 27 1/02Revision 0: Initial Version Rev. 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