AD7946 Analog Devices, AD7946 Datasheet
AD7946
Specifications of AD7946
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AD7946 Summary of contents
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... BUSY indicator compatible with 1 logic, using the separate supply VIO. The AD7946 is housed in a 10-lead MSOP or a 10-lead QFN (LFCSP) with operation specified from −40°C to +85°C. 250 kSPS 400 kSPS to 500 kSPS ...
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... CS MODE 3-Wire, No BUSY Indicator .................................. 17 CS Mode 3-Wire with BUSY Indicator ................................... 18 CS Mode 4-Wire, No BUSY Indicator..................................... 19 CS Mode 4-Wire with BUSY Indicator ................................... 20 Chain Mode, No BUSY Indicator ............................................ 21 Chain Mode with BUSY Indicator........................................... 22 Application Guidelines .................................................................. 23 Layout .......................................................................................... 23 Evaluating the AD7946’s Performance.................................... 23 Outline Dimensions ....................................................................... 24 Ordering Guide .......................................................................... 24 Rev Page ...
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... Full-scale step kHz, REF = kHz, REF = 2 kHz kHz kHz, REF = kHz, REF = 5 V, −60 dB input IN Rev Page AD7946 Min Typ Max Unit 14 Bits 0 REF V −0.1 VDD + 0.1 V −0.1 0 See the Analog Input section ...
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... AD7946 VDD = 4 5.5 V, VIO = 2 VDD, REF = VDD, T Table 3. Parameter Conditions REFERENCE Voltage Range Load Current 500 kSPS, REF = 5 V SAMPLING DYNAMICS −3 dB Input Bandwidth Aperture Delay VDD = 5 V DIGITAL INPUTS Logic Levels DIGITAL OUTPUTS Data Format ...
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... CYC t CNVH t SCK t SCK t SCKL t SCKH t HSDO t DSDO DIS t SSDICNV t HSDICNV t SSCKCNV t HSCKCNV t SSDISCK t HSDISCK t DSDOSDI Rev Page AD7946 Min Typ Max Unit 0.5 1.6 μs 400 ns 2 μ ...
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... AD7946 ABSOLUTE MAXIMUM RATINGS Table 5. Parameter Rating Analog Inputs IN IN− 1 GND − 0 VDD + 0 ±130 mA REF GND − 0 VDD + 0.3 V Supply Voltages VDD, VIO to GND −0 VDD to VIO ±7 V Digital Inputs to GND −0 VIO + 0.3 V Digital Outputs to GND − ...
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... V analog input digital input digital output, and P = power. VIO SDI SCK SDO CNV Rev Page REF 1 VIO 10 VDD 2 SDI 9 AD7946 IN+ 3 TOP VIEW 8 SCK (Not to Scale) 4 IN– 7 SDO 5 GND 6 CNV Figure 5. 10-Lead QFN (LFCSP) Pin Configuration AD7946 ...
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... AD7946 TYPICAL PERFORMANCE CHARACTERISTICS 1.0 POSITIVE INL = +0.17LSB 0.8 NEGATIVE INL = –0.26LSB 0.6 0.4 0.2 0 –0.2 –0.4 –0.6 –0.8 –1.0 0 4096 8192 CODE Figure 6. Integral Nonlinearity vs. Code 300000 261120 250000 200000 150000 100000 50000 2009 200A 200B 200C CODE IN HEX Figure 7. Histogram Input at the Code Center ...
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... REF = 5V –100 –110 –120 –130 85 105 125 –55 –60 –70 –80 –90 –100 –110 –120 150 200 0 Rev Page AD7946 THD SFDR 2.7 3.1 3.5 3.9 4.3 4.7 5.1 REFERENCE VOLTAGE (V) Figure 15. THD, SFDR vs. Reference Voltage REF = 5V –35 – 105 TEMPERATURE (°C) Figure 16. THD vs. Temperature REF = 5V, – ...
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... AD7946 1000 750 VDD 500 250 VIO 0 4.50 4.75 5.00 SUPPLY (V) Figure 18. Operating Current vs. Supply 1000 750 500 250 0 –55 –35 – TEMPERATURE (°C) Figure 19. Power-Down Current vs. Temperature 1000 750 VDD = 5V 500 250 VIO 0 –55 –35 – TEMPERATURE (°C) Figure 20. Operating Current vs. Temperature ...
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... CNV input and when the input signal is held for a conversion. Transient Response Transient response is the time required for the ADC to accu- rately acquire its input after a full-scale step function is applied. Rev Page AD7946 ...
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... The AD7946 is specified from 4 5.5 V and can be interfaced to any of the 1 digital logic family housed in a 10-lead MSOP or a tiny 10-lead QFN (LFCSP) that combines space savings and allows flexible configurations ...
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... TYPICAL CONNECTION DIAGRAM Figure 25 shows an example of the recommended connection diagram for the AD7946 when multiple supplies are available REF (ADA4841 V– OR NOTE 3) NOTES 1. SEE REFERENCE SECTION FOR REFERENCE SELECTION USUALLY A 10µF CERAMIC CAPACITOR (X5R). REF 3. SEE DRIVER AMPLIFIER CHOICE SECTION. ...
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... OP184 AD8605, AD8615 AD8519 AD8031 VOLTAGE REFERENCE INPUT The AD7946 voltage reference input REF has a dynamic input impedance and should therefore be driven by a low impedance source with efficient decoupling between the REF and GND 75 100 pins, as explained in the Layout section. When REF is driven by a very low impedance source, for example, a reference buffer using the 10 μ ...
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... POWER SUPPLY The AD7946 is specified uses two power supply pins: a core supply VDD and a digital input/output interface supply VIO. VIO allows direct interface with any logic between 1.8 V and VDD. To reduce the supplies needed, the VIO and VDD can be tied together. The AD7946 is independent of power supply sequencing between VIO and VDD ...
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... Figure 32. Example of a Single-Supply Application Circuit DIGITAL INTERFACE Although the AD7946 has a reduced number of pins, it offers flexibility in its serial interface modes. The AD7946, when in CS mode, is compatible with SPI, QSPI™, digital hosts, and DSPs, for example, Blackfin® ADSP-BF53x or ADSP-219x ...
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... CS MODE 3-WIRE, NO BUSY INDICATOR This mode is usually used when a single AD7946 is connected to an SPI-compatible digital host. The connection diagram is shown in Figure 33 and the corresponding timing is given in Figure 34. With SDI tied to VIO, a rising edge on CNV initiates a conversion, selects the CS mode, and forces SDO to high impedance ...
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... AD7946 CS MODE 3-WIRE WITH BUSY INDICATOR This mode is usually used when a single AD7946 is connected to an SPI-compatible digital host having an interrupt input. The connection diagram is shown in Figure 35, and the corresponding timing is given in Figure 36. With SDI tied to VIO, a rising edge on CNV initiates a conversion, selects the CS mode, and forces SDO to high impedance ...
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... Although the rising edge can be used to capture the data, a digital host using the SCK falling edge allows a faster reading rate, provided it has an acceptable hold time. After the 14 falling edge, or when SDI goes high, whichever is earlier, SDO returns to high impedance and another AD7946 can be read. CNV CNV AD7946 ...
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... AD7946 CS MODE 4-WIRE WITH BUSY INDICATOR This mode is usually used when a single AD7946 is connected to an SPI-compatible digital host, which has an interrupt input, and it is desired to keep CNV, which is used to sample the analog input, independent of the signal used to select the data reading. This requirement is particularly important in applications where low jitter on CNV is desired ...
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... The maximum conver- sion rate may be reduced due to the total readback time. For instance, with digital host setup time and 3 V interface four AD7946s running at a conversion rate of 360 kSPS can be daisy-chained on a 3-wire port. CNV ...
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... AD7946s in the chain, provided the digital host has an acceptable hold time. For instance, with digital host setup time and 3 V interface four AD7946s running at a conversion rate of 360 kSPS can be daisy-chained to a single 3-wire port. ...
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... The pinout of the AD7946, with all its analog signals on the left side and all its digital signals on the right side, eases this task. Avoid running digital lines under the device because these couple noise onto the die, unless a ground plane under the AD7946 is used as a shield ...
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... Temperature Range AD7946BRM −40°C to +85°C AD7946BRM-RL7 −40°C to +85°C 1 AD7946BRMZ −40°C to +85°C 1 AD7946BRMZRL7 −40°C to +85°C 1 AD7946BCPZRL7 −40°C to +85°C 1 AD7946BCPZRL −40°C to +85° EVAL-AD7946CBZ EVAL-CONTROL BRD3Z RoHS Compliant Part. 2 This board can be used as a standalone evaluation board or in conjunction with the EVAL-CONTROL BRD3Z for evaluation/demonstration purposes ...