AD977 Analog Devices, AD977 Datasheet
AD977
Specifications of AD977
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AD977 Summary of contents
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... GENERAL DESCRIPTION The AD977/AD977A is a high speed, low power 16-bit A/D converter that operates from a single 5 V supply. The AD977A has a throughput rate of 200 kSPS whereas the AD977 has a throughput rate of 100 kSPS. Each part contains a successive approximation, switched capacitor ADC, an internal 2.5 V reference, and a high speed serial interface ...
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... AD977/AD977A AD977–SPECIFICATIONS Parameter RESOLUTION ANALOG INPUT Voltage Range Impedance Sampling Capacitance THROUGHPUT SPEED Complete Cycle Throughput Rate DC ACCURACY Integral Linearity Error Differential Linearity Error No Missing Codes 2 Transition Noise 3, 4 Full-Scale Error Full-Scale Error Drift Full-Scale Error Ext. REF = 2.5 V Full-Scale Error Drift Ext ...
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... AD977/AD977A = unless otherwise noted) DIG ANA C Grade Max Min Typ Max 200 ± 2.0 ± 3 ± 2 +1.75 15 1.0 ± 0.25 ± 0.5 ± 7 ± 0.25 ± 0.5 ± 2 ± 10 ± 15 ± 2 ± 10 ± 10 ± ...
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... Specifications subject to change without notice. (Both Specs) Min –0.3 2.0 Binary Two’s Complement or Straight Binary Conversion Results Only Available after Completed Conversion = 1 500 µA 4 4.75 4. –40 MIN MAX (AD977A 200 kHz, AD977 100 kHz Symbol Min ...
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... ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the AD977/AD977A feature proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high-energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality ...
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... DATACLK periods after the initiation of the read sequence. Dependent on whether a SYNC is not present or present. Read/Convert Input. Is used to control the conversion and read modes of the AD977. With CS LOW; a falling edge on R/C holds the analog input signal inter- nally and starts a conversion, a rising edge enables the transmission of the conver- sion result. ...
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... R/C input to when the input signal is held for a conversion. TRANSIENT RESPONSE The time required for the AD977/AD977A to achieve its rated accuracy after a full-scale step function is applied to its input. OVERVOLTAGE RECOVERY The time required for the ADC to recover to full accuracy after an analog input signal 150% of full-scale is reduced to 50% of the full-scale value ...
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... Conversion results can be clocked serially out of the AD977/ AD977A using either an internal clock, generated by the AD977/AD977A using an external clock. The AD977/ AD977A is configured for the internal data clock mode by pull- ing the EXT/INT pin low configured for the external clock mode by pulling the EXT/INT pin high. ...
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... When reading data after the conversion is complete, with the highest frequency permitted for DATACLK (15.15 MHz), and with the AD977A, the maximum possible throughput is approxi- mately 195 kHz and not the rated 200 kHz. For details on use of the TAG input with this mode see the Use of the Tag Feature section ...
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... DATACLK (if provided) the DATA output pin will reflect the state of the TAG input pin during the first rising edge of DATACLK. For both the AD977 and the AD977A the data should be clocked out during the first half of BUSY so not to degrade conversion performance. For the AD977 this requires use ...
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... TAG input pin during the rising edge of clock pulse # BIT 15 BIT 14 (MSB) CS AD977/AD977A BIT 0 TAG 0 TAG 1 TAG 2 (LSB) TAG 16 TAG 17 TAG 18 TAG 19 INT ) clock pulse #1 can be taken high ...
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... AD977/AD977A For both the AD977 and the AD977A the data should be clocked out during the first half of BUSY so not to degrade conversion performance. For the AD977 this requires use of a 4.8 MHz DATACLK or greater, with data being read out as soon as the conversion process begins. For the AD977A it requires use MHz DATACLK or greater ...
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... DATA output pin will reflect the state of the TAG input pin during the rising edge of clock pulse #2. For both the AD977 and the AD977A the data should be clocked out during the 1st half of BUSY so as not to degrade conversion performance. For the AD977 this requires use ...
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... ADC can be driven by a wide selection of general purpose amplifiers. To best match the low distortion requirements of the AD977/ AD977A, care should be taken in the selection of the drive cir- cuitry op amp. Figure 10 shows the simplified analog input section for the AD977/AD977A ...
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... R3 IN AD8031 CAP 2.2 F AD977A REF 2.2 F AGND2 AD977/AD977A Digital Output Two’s Complement Straight Binary (SB/BTC LOW) (SB/BTC HIGH µV 3.999939 V 0111 1111 1111 1111 1111 1111 1111 1111 2 V 0000 0000 0000 0000 1000 0000 0000 0000 1.999939 V 1111 1111 1111 1111 0111 1111 1111 1111 ...
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... AD977/AD977A INPUT STANDARD CONNECTION WITHOUT OFFSET AND GAIN ADJUST RANGE V IN 10V 3.33V BIPOLAR CONNECTION FOR AD977 STANDARD CONNECTION WITH 200 R1 IN AGND1 100 R2 IN 33. 50k CAP 2.2 F AD977 REF 2.2 F AGND2 200 R1 IN AGND1 100 R2 IN 33. CAP 2.2 F AD977 REF 2 ...
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... UNIPOLAR CONNECTION FOR AD977A AND AD977 INPUT STANDARD CONNECTION WITHOUT OFFSET AND GAIN ADJUST RANGE 200 100 V IN 33.2k 0V–10V 2.2 F 2.2 F 200 100 33. 0V–5V 2.2 F 2.2 F 200 V IN 100 33.2k 0V–4V 2.2 F 2.2 F STANDARD CONNECTION WITH OFFSET AND GAIN ADJUST 200 R1 IN AGND1 100 ...
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... It is important to note that in Figure 16a the R3 connected to the CAP pin whereas in Figure 16b the R3 of the AD977A is returned to the output of the external refer- ence. The AD780 is a bandgap reference that exhibits ultralow drift, low initial error and low output noise. In Figure 16b, the value for C1 is only applicable to applications using the AD780 ...
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... FREQUENCY – kHz the AD977/AD977A could be oversampled by a factor of 2/4. This would yield a 3/6 dB improvement in the effective SNR performance. DC PERFORMANCE The factory calibration scheme used for the AD977/AD977A compensates for bit weight errors that may exist in the capacitor array. The mismatch in capacitor values is adjusted (using the calibration coefficients) during a conversion resulting in excel- lent dc linearity performance ...
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... POSITIVE DNL – LSB NEGATIVE DNL – LSB 90 SNR+D (dB) FOR AD977A SNR+D (dB) FOR AD977 100 INPUT SIGNAL FREQUENCY – kHz 110 SFDR 105 100 95 THD 90 85 SNRD 80 –75 –50 –25 ...
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... TAG feature. To improve the data throughput a combination of the two data read methods can be used and is described as follows. If two or more AD977/AD977As are to have their data output concatenated together in a single data stream, and if data throughput maximized, a system could be designed such ...
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... AD977/AD977A by forcing through PF1 – enable SPORT0 Receive Interrupt through the IMASK register – wait for at least one full conversion cycle of the AD977/AD977A and throw away the received data – disable the AD977/AD977A by forcing through PF1 – ...
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... R/C to the ADC. The digital ground pin, DGND, is the reference AD977/ AD977A point for all of the digital signals that control the AD977/AD977A. CS The AD977/AD977A can be powered with two separate power EXT/INT supplies or with a single analog supply. When the system digital ...
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... AD977/AD977A 0.210 (5.33) 0.160 (4.06) 0.115 (2.93) 0.0118 (0.30) 0.0040 (0.10) 0.078 (1.98) 0.068 (1.73) 0.008 (0.203) 0.002 (0.050) OUTLINE DIMENSIONS Dimensions shown in inches and (mm). 20-Lead Plastic DIP (N-20) 1.060 (26.90) 0.925 (23.50 0.280 (7.11) 0.240 (6.10 0.060 (1.52) PIN 1 0.015 (0.38) MAX 0.130 (3.30) MIN SEATING 0.100 0.070 (1.77) 0.022 (0.558) PLANE (2.54) 0.014 (0.356) ...