AD7322 Analog Devices, AD7322 Datasheet
AD7322
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AD7322 Summary of contents
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... The ADC contains a 2.5 V internal reference. The AD7322 also allows for external reference operation reference is applied to the REFIN/OUT pin, the AD7322 can accept a true bipolar ±12 V analog input. Minimum ± supplies are required for the ±12 V input range. The ADC has a high speed serial interface that can operate at throughput rates MSPS ...
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... Full Shutdown Mode (PM1 = PM0 = 1) ................................. 27 Autoshutdown Mode (PM1 = 1, PM0 = 0) ............................. 28 Autostandby Mode (PM1 = 0, PM0 = 1) ................................ 28 Power vs. Throughput Rate ....................................................... 29 Serial Interface ................................................................................ 30 Microprocessor Interfacing ........................................................... 31 AD7322 to ADSP-21xx .............................................................. 31 AD7322 to ADSP-BF53x ........................................................... 31 Application Hints ........................................................................... 32 Layout and Grounding .............................................................. 32 Power Supply Configuration .................................................... 32 Outline Dimensions ....................................................................... 33 Ordering Guide .......................................................................... 33 Changes to Figure 40 and Figure 41............................................. 20 Changes to Autostandby Mode (PM1 = Section ...
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... Bits sign (13 bits) 11-bit plus Bits sign (12 bits) ±1.1 LSB ±1 LSB −0.7/+1.2 LSB Rev Page AD7322 = 3.0 V DRIVE REF Test Conditions/Comments kHz sine wave IN Differential mode Single-ended/pseudo differential mode Differential mode; ±2.5 V and ±5 V ranges Differential mode +10 V and ±10 V ranges Single-ended/pseudo differential mode ...
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... AD7322 1 Parameter 2 Differential Nonlinearity Offset Error Offset Error Match 2, 4 Gain Error 2, 4 Gain Error Match 2, 5 Positive Full-Scale Error Positive Full-Scale Error Match Bipolar Zero Error 2, 5 Bipolar Zero Error Match 2, 5 Negative Full-Scale Error 2, 5 Negative Full-Scale Error Match ...
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... Rev Page AD7322 Test Conditions/Comments DRIVE I = 200 μA SOURCE I = 200 μA SINK Coding bit set control register Coding bit set control register 16 SCLK cycles with SCLK = 20 MHz Full-scale step input ...
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... AD7322 TIMING SPECIFICATIONS Unless otherwise noted 16 2 3.0 V internal/external, T REF Table 3. Limit MIN MAX Parameter V < SCLK × × t CONVERT SCLK SCLK QUIET ...
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... ESD 2 the analog inputs are driven from alternative V Schottky diodes should be placed in series with the AD7322’s V supplies. See the Power Supply Configuration section. 2 Transient currents 100 mA do not cause SCR latch-up. Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only ...
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... V Positive Power Supply Voltage. This is the positive supply voltage for the analog input section Analog Supply Voltage, 2 5.25 V. This is the supply voltage for the ADC core on the AD7322. CC This supply should be decoupled to AGND Logic Power Supply Input. The voltage supplied at this pin determines at what voltage the interface DRIVE operates ...
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... INT/EXT 2.5V REFERENCE ±10V RANGE –0.8 +INL = +0.87LSB –INL = –0.49LSB –1.0 0 1024 2048 3072 4096 5120 6144 512 1536 2560 3584 4608 5632 CODE Figure 9. Typical INL Single-Ended Mode AD7322 7168 8192 6656 7680 7168 8192 6656 7680 = 5V 7168 8192 6656 7680 ...
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... AD7322 – ±12V – 25° 1MSPS –60 S ±10V SE – +10V SE –70 ±10V DIFF –75 –80 –85 –90 –95 –100 10 100 ANALOG INPUT FREQUENCY (kHz) Figure 10. THD vs. Analog Input Frequency for Single-Ended (SE) and True Differential Mode (Diff – ...
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... RANGE 4700Ω 1000Ω, ±10V RANGE IN IN ±2.5V RANGE R = 2000Ω, IN ±2.5V RANGE R = 1000Ω, IN ±2.5V RANGE R = 100Ω, IN ±2.5V RANGE R = 50Ω, IN ±2.5V RANGE 10 100 ANALOG INPUT FREQUENCY (kHz) True Differential Mode AD7322 = 1200 1000 ...
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... AD7322 – DRIVE ±12V DD SS – 25°C A INTERNAL REFERENCE –60 RANGE = ±10V AND ±2.5V – 2000Ω, ±10V RANGE 1000Ω, ±10V RANGE –70 IN –75 –80 –85 –90 –95 10 100 INPUT FREQUENCY (kHz) Figure 22. THD vs. Analog Input Frequency for Various ...
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... N-bit converter with a sine wave input is given by Signal-to-(Noise + Distortion) = (6. 1.76) dB For a 13-bit converter, this is 80.02 dB. Total Harmonic Distortion Total harmonic distortion (THD) is the ratio of the rms sum of harmonics to the fundamental. For the AD7322 defined as where sixth harmonics. ...
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... The AD7322 is tested using the CCIF standard where two input frequencies near the top end of the input bandwidth are used. In this case, the second-order terms are usually distanced in frequency from the original sine waves, whereas the third-order terms are usually at a frequency close to the input frequencies ...
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... V, ±5 V, and ±2 can also accept +10 V unipolar input range. A different analog input range can be programmed on each analog input channel via the on-chip registers. The AD7322 has a high speed serial interface that can operate at throughput rates MSPS. The AD7322 requires V ...
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... DAC 1. IN ANALOG INPUT STRUCTURE The analog inputs of the AD7322 can be configured as single- ended, true differential, or pseudo differential via the control register mode bits (see Table 10). The AD7322 can accept true bipolar input signals. On power-up, the analog inputs operate as two single-ended analog input channels. If true differential or pseudo differential is required, a write to the control register is necessary after power-up to change this configuration ...
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... SOURCE where C is the sampling capacitance and R is the resistance seen by the track-and-hold amplifier looking back on the input. For the AD7322, the value of R includes the on resistance of the input multiplexer and is typically 300 Ω. R any extra source impedance on the analog input. ...
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... RANGE SELECTED. Figure 32. Typical Connection Diagram ANALOG INPUT Single-Ended Inputs The AD7322 has a total of two analog inputs when operating in single-ended mode. Each analog input can be independently programmed to one of the four analog input ranges. In applications where the signal source is high impedance recommended to buffer the signal before applying it to the ADC analog inputs ...
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... RANGE Figure 38. Common-Mode Range for V Pseudo Differential Inputs The AD7322 can have one pseudo differential pair. The input is coupled to the signal source and must have an amplitude within the selected range for that channel as programmed in the range register input is applied to the V applied to this input provides an offset for the V ± ...
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... The driver amplifier must be able to settle for a full-scale step to a 13-bit level, 0.0122%, in less than the specified acquisition time of the AD7322 amp such as the AD8021 meets this ±5V RANGE requirement when operating in single-ended mode. The ± ...
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... These registers are write-only registers. ADDRESSING REGISTERS A serial transfer on the AD7322 consists of 16 SCLK cycles. The three MSBs on the DIN line during the 16 SCLK transfer are decoded to determine which register is addressed. The three Table 8. Decoding Register Select Bit and Write Bit ...
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... Coding This bit is used to select the type of output coding the AD7322 uses for the next conversion result. If coding = 0, the output coding is twos complement. If coding = 1, the output coding is straight binary. When operating in sequence mode, the output coding for each channel is the value written to the coding bit during the last write to the control register ...
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... PM1 PM0 Description 1 1 Full shutdown mode. In this mode, all internal circuitry on the AD7322 is powered down. Information in the control register is retained when the AD7322 is in full shutdown mode Autoshutdown mode. The AD7322 enters autoshutdown on the 15 All internal circuitry is powered down in autoshutdown. ...
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... This combination selects the +10 V input range on V register select bit to 1. After the initial write to the range register occurs, each time an analog input is selected, the AD7322 automatically configures the analog input to the appropriate range, as indicated by the range register. The ±10 V input range is selected by default on each analog input channel (see Table 13) ...
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... Figure 44). This sequence begins by converting on Channel 0 and ends with a final channel selected by Bit ADD0 in the control register. To operate the AD7322 in this mode, set Seq1 to 1 and Seq2 to 0, and then select the final channel in the sequence by programming Bit ADD0 in the control register ...
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... The AD7322 is specified for a 2 reference range. When reference is selected, the ranges are ±12 V, ±6 V, ±3 V, and +12 V. For these ranges, the V must be equal to or greater than the maximum analog input range selected (see Table 6) ...
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... Serial A write to the control register with PM1 = 1 and PM0 = 1 places the part into full shutdown mode. The AD7322 enters full shut- down mode on the 15 is updated write to the control register occurs while the part is in full ...
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... This mode is similar to auto- shutdown, but allows the AD7322 to power up much faster. This allows faster throughput rates to be achieved the case with the autoshutdown mode, the AD7322 enters standby on the 15 is updated (see Figure 47). The part retains information in the registers during standby ...
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... POWER vs. THROUGHPUT RATE The power consumption of the AD7322 varies with throughput rate. The static power consumed by the AD7322 is very low, and a significant power savings can be achieved as the throughput rate is reduced. Figure 48 and Figure 49 shows the power vs. throughput rate for the AD7322 respectively ...
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... WRITE ZERO DIN Data is clocked into the AD7322 on the SCLK falling edge. The three MSBs on the DIN line are decoded to select which register is addressed. The control register is a 12-bit register. If the control register is addressed by the three MSBs, the data on the DIN line is loaded into the control on the 15 ...
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... MICROPROCESSOR INTERFACING The serial interface on the AD7322 allows the part to be directly connected to a range of different microprocessors. This section explains how to interface the AD7322 with some common micro- controller and DSP serial interface protocols. AD7322 TO ADSP-21xx The ADSP-21xx family of DSPs interface directly to the AD7322 without requiring glue logic ...
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... All AGND pins on the AD7322 should be connected to the AGND plane. Digital and analog ground pins should be joined in only one place. If the AD7322 system where multiple devices require an AGND and DGND connection, the connection should still be made at only one point ...
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... Z = RoHS Compliant Part. 2 This can be used as a standalone evaluation board or in conjunction with the EVAL- 3 This board is a complete unit allowing control and communicate with evaluation kit, the particular ADC evaluation board (for example, EVAL-AD7322CBZ), evaluation board data sheet for more information. 5.10 5.00 4.90 ...
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... AD7322 NOTES Rev Page ...
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... NOTES Rev Page AD7322 ...
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... AD7322 NOTES ©2005–2010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D04863-0-1/10(A) Rev Page ...