Datasheet AD7934-6 (Analog Devices)

4-Channel, 625 kSPS, 12-Bit Parallel ADC with a Sequencer AD7934-6 FEATURES FUNCTIONAL BLOCK DIAGRAM Throughput rate: 625 kSPS VDD AGND Specified for VDD of 2.7 V to 5.25 V V AD7934-6 REFIN/ Power consumption VREFOUT 3.6 mW maximum at 625 kSPS with 3 V supplies 2.5V VREF 7.5 mW maximum at 625 kSPS with 5 V supplies VIN0 CLKIN 4 analog input channels with a sequencer 12-BIT I/P SAR ADC T/H CONVST Software-configurable analog inputs MUX AND CONTROL BUSY 4-channel single-ended inputs VIN3 2-channel fully differential inputs 2-channel pseudo differential inputs SEQUENCER Accurate on-chip 2.5 V reference ±0.2% maximum @ 25°C, 25 ppm/°C maximum PARALLEL INTERFACE/CONTROL REGISTER V 70 dB SINAD at 50 kHz input frequency DRIVE No pipeline delays High speed parallel interface—word/byte modes
01 0 2-
Full shutdown mode: 2 μA maximum
75
DB0 DB11 CS RD WR W/B DGND
04
28-lead TSSOP package
Figure. 1
GENERAL DESCRIPTION
The AD7934-6 is a 12-bit, high speed, low power, successive features flexible power management options. An on-chip control approximation (SAR) analog-to-digital converter (ADC). The register allows the user to set up different operating conditions, part operates from a single 2.7 V to 5.25 V power supply and including analog input range and configuration, output coding, features throughput rates up to 625 kSPS. The part contains a power management, and channel sequencing. low noise, wide bandwidth, differential track-and-hold
PRODUCT HIGHLIGHTS
amplifier that handles input frequencies up to 50 MHz. 1. High throughput with low power consumption. The AD7934-6 features four analog input channels with a channel 2. Four analog inputs with a channel sequencer. sequencer that allows a preprogrammed selection of channels to 3. Accurate on-chip 2.5 V reference. be converted sequentially. This part can accept either single- 4. Single-ended, pseudo differential, or fully differential ended, fully differential, or pseudo differential analog inputs. analog inputs that are software selectable. Data acquisition and conversion are controlled by standard control 5. No pipeline delay. inputs that allow for easy interfacing to microprocessors and 6. Accurate control of the sampling instant via a CONVST DSPs. The input signal is sampled on the falling edge of CONVST, input and once-off conversion control. which is also the point where the conversion is initiated.
Table 1. Related Devices
The AD7934-6 has an accurate on-chip 2.5 V reference that
Similar Device No. of Bits No. of Channels Speed
can be used as the reference source for the analog-to-digital AD7938/AD7939 12/10 8 1.5 MSPS conversion. Alternatively, this pin can be overdriven to provide AD7933/AD7934 10/12 4 1.5 MSPS an external reference. AD7938-6 12 8 625 kSPS The AD7934-6 uses advanced design techniques to achieve very low power dissipation at high throughput rates. The part also
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Document Outline FEATURES FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION PRODUCT HIGHLIGHTS REVISION HISTORY SPECIFICATIONS TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS TERMINOLOGY CONTROL REGISTER SEQUENCER OPERATION Writing to the Control Register to Program the Sequencer CIRCUIT INFORMATION CONVERTER OPERATION ADC TRANSFER FUNCTION TYPICAL CONNECTION DIAGRAM ANALOG INPUT STRUCTURE ANALOG INPUT CONFIGURATIONS Single-Ended Mode Differential Mode Driving Differential Inputs Using an Op Amp Pair Pseudo Differential Mode ANALOG INPUT SELECTION Traditional Multichannel Operation (SEQ0 = SEQ1 = 0) Using the Sequencer: Consecutive Sequence (SEQ0 = SEQ1 = 1) REFERENCE Digital Inputs VDRIVE Input PARALLEL INTERFACE Reading Data from the AD7934-6 Writing Data to the AD7934-6 POWER MODES OF OPERATION Normal Mode (PM1 = PM0 = 0) Autoshutdown Mode (PM1 = 0; PM0 = 1) Autostandby Mode (PM1 = 1; PM0 = 0) Full Shutdown Mode (PM1 = 1; PM0 = 1) POWER vs. THROUGHPUT RATE MICROPROCESSOR INTERFACING AD7934-6 to ADSP-21xx Interface AD7934-6 to ADSP-21065L Interface AD7934-6 to TMS32020, TMS320C25, and TMS320C5x Interface AD7934-6 to 80C186 Interface APPLICATION HINTS GROUNDING AND LAYOUT EVALUATING THE AD7934-6 PERFORMANCE OUTLINE DIMENSIONS ORDERING GUIDE