AD7656-1 Analog Devices, AD7656-1 Datasheet
AD7656-1
Specifications of AD7656-1
Related parts for AD7656-1
AD7656-1 Summary of contents
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... DSPs. When the serial interface is selected, each part has a daisy-chain feature that allows multiple ADCs to connect to a single serial interface. The AD7656-1/AD7657-1/ AD7658-1 can accommodate true bipolar input signals in the ±4 × V and ± ...
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... AD7656-1/AD7657-1/AD7658-1 TABLE OF CONTENTS Features .............................................................................................. 1 Applications....................................................................................... 1 Functional Block Diagram .............................................................. 1 General Description ......................................................................... 1 Product Highlights ........................................................................... 1 Revision History ............................................................................... 2 Specifications..................................................................................... 3 AD7656-1 ...................................................................................... 3 AD7657-1 ...................................................................................... 5 AD7658-1 ...................................................................................... 7 Timing Specifications .................................................................. 9 Absolute Maximum Ratings.......................................................... 10 Thermal Resistance .................................................................... 10 ESD Caution................................................................................ 10 Pin Configuration and Function Descriptions........................... 11 Typical Performance Characteristics ........................................... 14 Terminology .................................................................................... 18 REVISION HISTORY 11/10—Rev Rev. C Added Power Supply Configuration Section ...
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... V ±1 μA 18.5 pF 2.49 2.51 V 150 ppm 25 ppm/°C 6 ppm/°C Rev Page AD7656-1/AD7657-1/AD7658 5.25 V; for the ±4 × V DRIVE REF = − −16 250 kSPS SAMPLE Test Conditions/Comments kHz sine wave ± ±16 ...
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... AD7656-1/AD7657-1/AD7658-1 Parameter LOGIC INPUTS Input High Voltage (V ) INH Input Low Voltage (V ) INL Input Current ( Input Capacitance ( LOGIC OUTPUTS Output High Voltage ( Output Low Voltage ( Floating-State Leakage Current 2 Floating-State Output Capacitance Output Coding CONVERSION RATE Conversion Time ...
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... V DRIVE 0.3 × DRIVE ±10 μ Rev Page AD7656-1/AD7657-1/AD7658 5.25 V; for the ±4 × V range, V REF = − −16 250 kSPS SAMPLE Test Conditions/Comments kHz sine wave 10.5 kHz 9.5 kHz ...
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... AD7656-1/AD7657-1/AD7658-1 Parameter Min LOGIC OUTPUTS Output High Voltage ( Output Low Voltage ( Floating-State Leakage Current Floating-State Output Capacitance 2 Output Coding CONVERSION RATE Conversion Time 1, 2 Track-and-Hold Acquisition Time Throughput Rate POWER REQUIREMENTS V − − 4. 4. 2.7 DRIVE ...
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... V DRIVE 0.3 × DRIVE ±10 μ Rev Page AD7656-1/AD7657-1/AD7658 5.25 V; for ±4 × V range, V REF = 250 kSPS SAMPLE A MIN Test Conditions/Comments kHz sine wave 10.5 kHz 9.5 kHz f on unselected channels up to 100 kHz IN @ − ...
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... AD7656-1/AD7657-1/AD7658-1 Parameter Min LOGIC OUTPUTS Output High Voltage ( Output Low Voltage ( Floating-State Leakage Current Floating-State Output 2 Capacitance Output Coding CONVERSION RATE Conversion Time 1, 2 Track-and-Hold Acquisition Time Throughput Rate POWER REQUIREMENTS V − − 4. 4. 2.7 DRIVE ...
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... TO OUTPUT PIN C L 25pF 200µ Figure 2. Load Circuit for Digital Output Timing Specifications Rev Page AD7656-1/AD7657-1/AD7658 2.5 V internal/external, DRIVE REF Unit Description μs typ Conversion time, internal clock ns min Minimum quiet time required between bus ...
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... If the analog inputs are driven from alternative V a 240 Ω series resistor should be placed on the analog inputs and Schottky diodes should be placed in series with the V DD AD7656-1/AD7657-1/AD7658-1. 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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... RANGE pin. In software mode determined by the RNGC to RNGA bits of the control register (see Table 11). Analog Ground. This pin is the ground reference point for all analog circuitry on the AD7656-1/ AD7657-1/AD7658-1. Refer all analog input signals and external reference signals to this pin. ...
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... Busy Output. This pin transitions to high when a conversion is started and remains high until the conversion is complete and the conversion data is latched into the output data registers. A new conversion cannot be initiated on the AD7656-1/AD7657-1/AD7658-1 when the BUSY signal is high because any applied CONVST edges are ignored. ...
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... When the serial interface is selected, CONVST A is used to initiate conversions on the selected ADC pairs. Word/Byte Input. When this pin is logic low, data can be transferred to and from the AD7656-1/ AD7657-1/AD7658-1 using the parallel data lines DB[15:0]. When this pin is logic high and the parallel interface is selected, byte mode is enabled ...
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... TYPICAL PERFORMANCE CHARACTERISTICS 0 –20 –40 –60 –80 –100 –120 –140 –160 –180 FREQUENCY (kHz) Figure 4. AD7656-1 FFT for ±5 V Range (V 0 –20 –40 –60 –80 –100 –120 –140 –160 –180 FREQUENCY (kHz) Figure 5. AD7656-1 FFT for ±5 V Range (V 2 ...
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... 25°C –85 A INTERNAL REFERENCE ±2 × –90 –95 –100 –105 –110 –115 100 10 Figure 15. AD7656-1 THD vs. Analog Input Frequency for Various Source Rev Page 250kSPS ±10V RANGE ±12V / DRIVE ±5V RANGE ± ...
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... ±12V DD SS –110 ±10V RANGE –115 AV / ±16. –120 –60 –40 – TEMPERATURE (°C) Figure 21. AD7656-1 THD vs. Temperature = 250kSPS RANGE AND 430 480 530 = 5.25V 100 120 140 = 5.25V DRIVE 100 120 140 ...
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... Figure 23. Dynamic Current vs. Temperature 120 140 Figure 24. PSRR vs. Supply Ripple Frequency for AV 80 100 120 Rev Page AD7656-1/AD7657-1/AD7658 250kSPS SAMPLE ±2 × V RANGE REF INTERNAL REFERENCE T = 25° 10kHz IN 1µ SUPPLY PIN CC ± ...
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... LSB) after REF (fa − 2fb). The AD7656-1/AD7657-1/AD7658-1 are tested using the CCIF standard in which two input frequencies near the maximum input bandwidth are used. In this case, the second-order terms are usually distanced in frequency from the original sine waves, and the third-order terms are usually at a frequency close to the input frequencies ...
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... Figure 19 shows the power supply rejection ratio vs. supply ripple frequency for the AD7656-1/AD7657-1/AD7658-1. The power supply rejection ratio is defined as the ratio of the power in the ADC output at full-scale frequency the power of a 200 mV p-p sine wave applied to the V DD ADC at a frequency sampled, f ...
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... AD7658 devices. In addition, the AD7656-1/AD7657-1/AD7658-1 are high speed, low power converters that allow the simultaneous sampling of six on-chip ADCs. The analog inputs on the AD7656-1/ AD7657-1/AD7658-1 can accept true bipolar input signals. The RANGE pin or RNGx bits are used to select either ±4 × V ± ...
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... REFCAPx pins. TYPICAL CONNECTION DIAGRAM Figure 28 shows the typical connection diagram for the AD7656-1/ AD7657-1/AD7658-1, illustrating the reduction in the number and value of decoupling capacitors that are required. There are ...
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... DRIVING THE ANALOG INPUTS Together, the driver amplifier and the analog input circuit used for the AD7656-1 must settle for a full-scale step input to a 16-bit level (0.0015%), which is within the specified 550 ns acquisition time of the AD7656-1. The noise generated by the driver amplifier needs to be kept as low as possible to preserve the SNR and transition noise performance of the AD7656-1 ...
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... For unused input channel pairs, tie the associated CONVST pin to V DRIVE If there is only an 8-bit bus available, the AD7656-1/AD7657-1/ AD7658-1 parallel interface can be configured to operate in byte mode ( 1). In this configuration, the DB7/HBEN/DCEN ). If CONVST A pin takes on its HBEN function ...
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... ADC pair. DB12 to DB10 in the control register are used to program the range on each ADC pair. After a reset occurs on the AD7656-1/AD7657-1/AD7658-1, the control register contains all 0s. The CONVST A signal is used to initiate a simultaneous conversion on the combination of channels selected via the control register ...
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... VREF. When the RNGx bit is set to 0, the range for the next conversion is ±4 × VREF. Serial Interface (SER/ PAR SEL = 1) By pulsing one, two, or all three CONVST signals, the AD7656-1/ AD7657-1/AD7658-1 use their on-chip trimmed oscillator to simultaneously convert the selected channel pairs on the rising edge of CONVST ...
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... CONVST A, CONVST B, t CONV CONVST C BUSY ACQUISITION CONVERSION CS SCLK DOUT A, DOUT B, DOUT C 16 clock pulses must be provided to the AD7656-1/AD7657-1/ AD7658-1. access the conversion results. t ACQ Figure 32. Serial Interface with Three DOUT Lines Figure 33. Serial Interface with Two DOUT Lines ...
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... DAISY-CHAIN MODE (DCEN = 1, SER/PAR SEL = 1) When reading conversion data back from the AD7656-1/AD7657-1/ AD7658-1 using one/two/three DOUT pins possible to configure the parts to operate in daisy-chain mode by using the DCEN pin. This daisy-chain feature allows multiple AD7656-1/ AD7657-1/AD7658-1 devices to be cascaded together and is useful for reducing the component count and wiring connections ...
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... SCLK DEVICE 1, DOUT A MSB V1 DEVICE 1, DOUT B MSB V3 DEVICE 1, DOUT C MSB V5 DEVICE 2, DOUT A MSB V1 DEVICE 2, DOUT B MSB V3 DEVICE 2, DOUT C MSB V5 CONVST DCIN A DOUT A DOUT A AD7656-1/ AD7657-1/ DCIN B DOUT B DOUT B AD7658-1 CS SCLK CS DCEN = 1 DEVICE 1 Figure 36. Daisy-Chain Configuration LSB V1 MSB V2 ...
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... APPLICATION HINTS LAYOUT Design the printed circuit board (PCB) that houses the AD7656-1/ AD7657-1/AD7658-1 so that the analog and digital sections are separated and confined to different areas of the board. Use at least one ground plane. It can be common or split between the digital and analog sections. In the case of the split ...
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... This board is a complete unit allowing control and communicate with all Analog Devices, Inc., evaluation boards ending in the CB designators. To order a complete evaluation kit, the particular ADC evaluation board, for example, EVAL-AD7656-1/AD7657-1/AD7658-1CB, the EVAL-CONTROL BRD2, and transformer must be ordered. See the relevant evaluation board technical note for more information. ...
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... AD7656-1/AD7657-1/AD7658-1 NOTES Rev Page ...
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... AD7656-1/AD7657-1/AD7658-1 NOTES ©2008–2010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D07017-0-11/10(C) Rev Page ...