AD1555 Analog Devices, AD1555 Datasheet
AD1555
Specifications of AD1555
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AD1555 Summary of contents
Page 1
... CMOS transistors. The AD1555 and AD1556 are packaged, respectively, in 28-lead PLCC and 44-lead MQFP packages and are specified from –55°C to +85°C (AD1556 and AD1555 B Grade) and from 0°C to 85°C (AD1555 A Grade). FUNCTIONAL BLOCK DIAGRAM ...
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... –55 MIN MAX 2.990 –0.3 2.0 –10 – SINK = –2 mA 2.4 SOURCE –2– AGND = DGND = 0 V; MCLK = 256 kHz AD1555AP Typ Max Min Typ Max 120 116 120 119.5 115.5 119.5 117.5 114 117.5 109.5 104.5 109 – ...
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... Hz and 50 Hz, each 6 dB down full scale This specification is for the AD1555 only and does not include the errors from external components as, for instance, the external reference. 6 This offset specification is referred to the modulator output. ...
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... Input and Gain MODIN kHz (1 ms) 116 500 Hz (2 ms) 119 250 Hz (4 ms) 122 O * Not tested in production. Guaranteed by design. Table Ib. Minimum Dynamic Performances (AD1555BP Only) Input and Gain MODIN kHz (1 ms) 116 500 Hz (2 ms) 119 250 Hz (4 ms) 122 Not tested in production ...
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... The gain of the modulator is proportional to f CLKIN 2 With DRDYBUF low only. When DRDYBUF is high, this timing also depends on the value of the external pull-down resistor. Specifications subject to change without notice. REV 5%; –V = –5 V 5%; AD1555 CLKIN = 1.024 MHz; AGND = DGND = Symbol f CLKIN ...
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... TDATA t 10 RESET CLKIN SYNC DRDY ERROR Figure 4. AD1556 RESET, DRDY, and Overwrite Timings DATA VALID VALID Figure 3. AD1555/AD1556 Interface Timing –6– DATA VALID VALID REV. B ...
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... DOUT SCLK R SCLK t 31 MSB DIN REV. B MSB MSB– Figure 5. Serial Read Timing MSB–1 Figure 6. Serial Write Timing –7– AD1555/AD1556 HI-Z LSB+1 LSB LSB+1 LSB ...
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... AGND . . . . . . . . . . . . . . . . . . . . . . . – +0 DGND . . . . . . . . . . . . . . . . . . . . . . . . –0 Ground Voltage Differences DGND, AGND1, AGND2, AGND3 . . . . . . . . . . . ± 0.3 V Digital Inputs . . . . . . . . . . . . . . . . . . . . –0 Internal Power Dissipation AD1555 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8 W AD1556 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8 W Model AD1555AP AD1555APRL AD1555BP AD1555BPRL AD1556AS AD1556ASRL EVAL-AD1555/AD1556EB AD1555/56-REF *Contact factory for extended temperature range. ...
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... PGA1 3 PGA2 4 PGA3 5 AD1556 PGA4 6 TOP VIEW (Not to Scale) BW0 7 BW1 8 9 BW2 10 H CONNECT –9– AD1555/AD1556 REFIN REFCAP2 REFCAP1 AGND3 –V A – CLKIN 31 SYNC 30 TDATA 29 CSEL PWRDN ...
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... Modulator Control. These input pins control the mux selection, the PGA gain settings, and the standby modes of the AD1555. When used with the AD1556, these pins are generally directly tied to the CB0–CB4 output pins of the AD1556. CB0–CB2 are generally used to set the PGA gain or cause it to enter in the PGA standby mode (refer to Table III) ...
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... CLKIN Clock Input. The clock input signal, nominally 1.024 MHz, provides the necessary clock for the AD1556. This clock frequency is divided by four to generate the MCLK signal for the AD1555. 35 MCLK Modulator Clock. Provides the modulator sampling clock frequency. The modulator always samples at one-fourth the CLKIN frequency ...
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... AD1555/AD1556 TERMINOLOGY DYNAMIC RANGE Dynamic range is the ratio of the rms value of the full scale to the total rms noise measured with the inputs shorted together in the bandwidth from the Nyquist frequency F value for dynamic range is expressed in decibels. SIGNAL-TO-NOISE RATIO (SNR) ...
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... TPC 5. Dynamic Range Distribution (272 Units) 150 f = 24.4Hz IN SNR = 68.2dB 140 THD = –120dB 130 120 110 100 90 3000 3500 4000 –55 TPC 6. Common-Mode Rejection vs. Temperature –13– AD1555/AD1556 2 8 128 –35 – 105 TEMPERATURE – C –121 –119 –117 –118 DYNAMIC RANGE – ...
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... AD1555/AD1556 –128 –120 –113 –105 CMRR – dB TPC 7. Common-Mode Rejection Distribution (272 Units) 120 G = 8.5 115 110 105 G = 128 G = 2.5 100 100 200 300 400 500 600 FREQUENCY – Hz TPC 8. Common-Mode Rejection vs. Frequency 0.20 0.15 0.10 0.05 0.00 –0.05 –0.10 –0.15 – ...
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... FREQUENCY – Hz TPC 14. AD1556 Pass Band Ripple, F REV. B 0.20 0.15 0.10 0.05 0.00 –0.05 –0.10 –0.15 –0.20 1500 2000 kHz (1/4 ms) TPC 15. AD1556 Pass Band Ripple 3000 4000 = 8 kHz (1/8 ms) O –15– AD1555/AD1556 4000 6000 8000 2000 FREQUENCY – kHz (1/16 ms) O ...
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... F The AD1555 operates from a dual analog supply (± 5 V), while the digital part of the AD1555 operates from supply. The AD1556 operates from a single 3 supply. Each device exhibits low power dissipation and can be configured for standby mode. ...
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... This combination allows accurate calibra- tion of the offset of the AD1555 for each gain setting. Also, a system noise calibration can be done using the internal 1 kΩ resistor as a noise reference. ...
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... Sigma-delta modulators have the potential to generate idle tones that occur for dc inputs close to ground. To prevent this unde- sirable effect, the AD1555 modulator offset is set to about –60 mV. In this manner, any existing idle tones are moved out of the band of interest and filtered out by the digital filter. ...
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... The AD1556 is a digital finite impulse response (FIR) linear phase low pass filter and serves as the decimation filter for the AD1555. It takes the output bitstream of the AD1555, filters and decimates user-selectable choice of seven different filters associated with seven decimation ratios, in power of 2 from 1/16 to 1/1024 ...
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... DIN, SCLK, CS, and R/W. In this mode, when RESET is active, the configuration register mimics the selec- tion of the hardware pins. The AD1556 and the AD1555 can be put in power-down by software. The DRDYBUF bit controls the operating mode of the DRDY output pin ...
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... This will re- duce the effect of feedthrough through the board. The power supply lines to the AD1555 should use as large a trace as possible to provide low impedance paths and reduce the effect of glitches on the power supply lines. Good decoupling is also important to lower the supplies impedance resent to the AD1555 and reduce the magnitude of the supply spikes ...
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... DB1 CB1 DB0 (LSB) CB0 The AD1555 has three different ground pins: AGND1, AGND2, and AGND3 plane, depending on the configuration. AGND1 should be a star point and be connected to the analog ground point. AGND2 should be directly tied to AGND1. A low impedance trace should connect in the following order: AGND3, the low side of the reference decoupling capacitor on REFCAP1, the ground of the reference voltage, and return to AGND1 ...
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... MAX SQ 0.390 (9.90) 0.041 (1.03) 0.029 (0.73 SEATING PLANE TOP VIEW (PINS DOWN) 11 0.010 (0.25 MAX 0.009 (0.23) 0.005 (0.13) 0.018 (0.45) 0.031 (0.80) BSC 0.012 (0.30) 0.083 (2.10) 0.077 (1.95) –23– AD1555/AD1556 0.025 (0.63) 0.015 (0.38) 0.021 (0.53) 0.013 (0.33) 0.430 (10.92) 0.390 (9.91) 0.032 (0.81) 0.026 (0.66) 0.040 (1.01) 0.025 (0.64 0.315 (8.00) REF 23 ...
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