ad7740 Analog Devices, Inc., ad7740 Datasheet
ad7740
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ad7740 Summary of contents
Page 1
... SOT-23 and 8-lead microSOIC packages, and is intended for low-cost applications. The AD7740 offers considerable space saving over alternative solutions. 2. The AD7740 operates from a single 5.25 V supply and consumes typically 0.9 mA when the input is unbuffered. It also contains an automatic power-down function ...
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... AD7740 SPECIFICATIONS 2 Parameter DC PERFORMANCE Integral Nonlinearity 3 CLKIN = 32 kHz CLKIN = 1 MHz 3 CLKIN = 32 kHz CLKIN = 1 MHz Offset Error Gain Error 3 Offset Error Drift 3 Gain Error Drift 3 Power Supply Rejection Ratio ANALOG INPUT, VIN Nominal Input Span Input Current REFERENCE VOLTAGE 5 REFIN Nominal Input Voltage ...
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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 AD7740 features 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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... The master clock for the device may be in the form of a crystal/resonator tied between this pin and CLKOUT. An external CMOS-compatible clock may also be applied to this input as the clock for the device. If CLKIN is inactive low for 1 ms (typ), the AD7740 automatically enters power-down. 3 GND Ground reference for all the circuitry on-chip ...
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... V and ± The ratio of the apparent change in input voltage to the change in VDD is measured in dBs. OUTPUT FREQUENCY FOUT 0.9 f CLKIN = 2.5 V. The deviation 0.1 f CLKIN AD7740 is 2.5 V and the VDD supply is varied REF GAIN ERROR IDEAL WITH OFFSET ERROR ONLY WITH OFFSET ERROR AND GAIN ERROR 0 ...
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... AD7740–Typical Performance Characteristics 0.015 VDD = 5V REFIN = 2.5V 0.01 CLKIN = 1MHz 0.005 BUFFER OFF 0 –0.005 BUFFER ON –0.01 –0.015 –0.5 0 0.5 1 1.5 2 2.5 VIN – REFIN = 2.5V CLKIN = 1MHz GAIN ERROR A BUF = 0 4 GAIN ERROR 0 OFFSET ERROR –4 – VDD – ...
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... CLKIN = 0.948 f CLKIN VFC Modulator The analog input signal to the AD7740 is continuously sampled by a switched capacitor modulator whose sampling rate is set by a master clock. The input signal may be buffered on-chip (BUF = 1) before being applied to the sampling capacitor of the modulator. This isolates the sampling capacitor charging currents from the analog input pin ...
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... Power-Down Mode When CLKIN is inactive low for 1 ms (typ), the AD7740 auto- matically enters a power-down mode. In this mode most of the digital and analog circuitry is shut down and REFOUT floats. ...
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... The input LED of the isolator is driven from the output of the AD7740. At the receiver side, the output transistor is operated in the photo-transistor mode. The pulse train can be reconverted to an analog voltage using a frequency- to-voltage converter ...
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... F noise onto the die. The analog ground plane should be allowed to run under the AD7740 to avoid noise coupling. The power supply lines to the AD7740 should use as large a trace as pos- sible to provide low impedance paths and reduce the effects of REFIN glitches on the power supply line. Fast switching signals like ...
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... SEATING 0.008 (0.20) PLANE 0.003 (0.08) 8-Lead SOT-23 (RT-8) 0.122 (3.10) 0.110 (2.80 0.071 (1.80) 0.059 (1.50 PIN 1 0.026 (0.65) BSC 0.077 (1.95) BSC 0.051 (1.30) 0.057 (1.45) 0.035 (0.90) 0.035 (0.90) 0.015 (0.38) 0.006 (0.15) SEATING 0.009 (0.23) 0.009 (0.22) PLANE 0.000 (0.00) 0.003 (0.08) AD7740 0.120 (3.05) 0.112 (2.84 0.028 (0.71) 0.016 (0.41) 10 0.022 (0.55) 0 0.014 (0.35) ...