Datasheet AD7904, AD7914, AD7924 (Analog Devices)

4-Channel, 1 MSPS, 8-/10-/12-Bit ADCs with Sequencer in 16-Lead TSSOP Data Sheet AD7904/ AD7914/ AD7924 FEATURES FUNCTIONAL BLOCK DIAGRAM Fast throughput rate: 1 MSPS AVDD Specified for AVDD of 2.7 V to 5.25 V REFIN Low power: 6 mW maximum at 1 MSPS with 3 V supplies VIN0 T/H 13.5 mW maximum at 1 MSPS with 5 V supplies 8-/10-/12-BIT SUCCESSIVE 4 single-ended inputs with sequencer VIN1 APPROXIMATION ADC I/P Wide input bandwidth MUX AD7924, 70 dB SNR at 50 kHz input frequency VIN2 Flexible power/serial clock speed management No pipeline delays VIN3 High speed serial interface: SPI/QSPI™/ SCLK MICROWIRE™/DSP compatible DOUT SEQUENCER CONTROL LOGIC Shutdown mode: 0.5 µA maximum DIN CS 16-lead TSSOP package AD7904/AD7914/AD7924 Qualified for automotive applications VDRIVE
001 03087-
AGND
Figure 1.
GENERAL DESCRIPTION PRODUCT HIGHLIGHTS
The AD7904/AD7914/AD7924 are, respectively, 8-bit, 10-bit, and 1. High Throughput with Low Power Consumption. 12-bit, high speed, low power, 4-channel successive approxi- The AD7904/AD7914/AD7924 offer throughput rates mation ADCs. The parts operate from a single 2.7 V to 5.25 V up to 1 MSPS. At the maximum throughput rate with 3 V power supply and feature throughput rates up to 1 MSPS. The supplies, the AD7904/AD7914/AD7924 dissipate only parts contain a low noise, wide bandwidth track-and-hold 6 mW of power maximum. amplifier that can handle input frequencies in excess of 8 MHz. 2. Four Single-Ended Inputs with Channel Sequencer. The conversion process and data acquisition are controlled using A consecutive sequence of channels can be selected, CS and the serial clock signal, al owing the device to easily inter- through which the ADC will cycle and convert on. face with microprocessors or DSPs. The input signal is sampled 3. Single-Supply Operation with VDRIVE Function. on the falling edge of CS and conversion is initiated at this The AD7904/AD7914/AD7924 operate from a single 2.7 V point. There are no pipeline delays associated with the part. to 5.25 V supply. The VDRIVE function al ows the serial inter- face to connect directly to 3 V or 5 V processor systems, The AD7904/AD7914/AD7924 use advanced design techniques independent of VDD. to achieve very low power dissipation at maximum throughput 4. Flexible Power/Serial Clock Speed Management. rates. At maximum throughput rates, the AD7904/AD7914/ The conversion rate is determined by the serial clock, AD7924 consume 2 mA maximum with 3 V supplies; with 5 V al owing the conversion time to be reduced by increasing supplies, the current consumption is 2.7 mA maximum. the serial clock speed. The parts also feature two shutdown Through the configuration of the control register, the analog modes to maximize power efficiency at lower throughput input range for the part can be selected as 0 V to REF rates. Current consumption is 0.5 µA maximum when in IN or 0 V to 2 × REF full shutdown. IN, with either straight binary or twos complement output coding. The AD7904/AD7914/AD7924 each feature four single- 5. No Pipeline Delay. ended analog inputs with a channel sequencer to allow a pre- The parts feature a standard successive approximation programmed selection of channels to be converted sequential y. ADC with accurate control of the sampling instant via The conversion time for the AD7904/AD7914/AD7924 is the CS input and once-off conversion control. determined by the SCLK frequency, which is also used as the master clock to control the conversion.
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Document Outline Features Functional Block Diagram General Description Product Highlights Revision History Specifications AD7904 Specifications AD7914 Specifications AD7924 Specifications Timing Specifications Absolute Maximum Ratings ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics Terminology Control Register Sequencer Operation Circuit Information Converter Operation Analog Input ADC Transfer Function Handling Bipolar Input Signals Typical Connection Diagram Analog Input Selection Digital Inputs VDRIVE Reference Modes of Operation Normal Mode (PM1 = PM0 = 1) Full Shutdown Mode (PM1 = 1, PM0 = 0) Auto Shutdown Mode (PM1 = 0, PM0 = 1) Powering Up the AD7904/AD7914/AD7924 Power vs. Throughput Rate Serial Interface Applications Information Microprocessor Interfacing AD7904/AD7914/AD7924 to TMS320C541 AD7904/AD7914/AD7924 to ADSP-218x AD7904/AD7914/AD7924 to DSP563xx Grounding and Layout Outline Dimensions Ordering Guide Automotive Products