AD654 Analog Devices, AD654 Datasheet
AD654
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AD654 Summary of contents
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... Low Power: 2.0 mA Quiescent Current Low Offset PRODUCT DESCRIPTION The AD654 is a monolithic V/F converter consisting of an input amplifier, a precision oscillator system, and a high current output stage. A single RC network is all that is required to set up any full scale (FS) frequency up to 500 kHz and any FS input voltage ...
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... The sink current is the amount of current that can flow into Pin 1 of the AD654 while maintaining a maximum voltage of 0.4 V between Pin 1 and Logic Common. Specifications shown in boldface are tested on all production units at final electrical test. Results from those tests are used to calculate outgoing quality levels. All min and max specifications are guaranteed, although only those shown in boldface are tested on all production units ...
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... S Storage Temperature Range . . . . . . . . . . . . . – +150 C Model Temperature Range AD654JN – +85 C AD654JR – +85 C REV –4) S ORDERING GUIDE Package Description 8-Lead Plastic DIP 8-Lead SOIC –3– AD654 Package Option N-8 SO-8 ...
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... Polystyrene, polypropylene, or Teflon* capacitors are preferred for tempco and dielectric absorption; other types will degrade linearity. The capacitor should be wired very close to the AD654. In Figure 1, Schottky diode CR1 (MBD101) prevents logic common from dropping more than 500 mV below –V required if – ...
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... COMP Figure 3b. Bias Current Compensation—Negative Inputs If the AD654’ offset voltage must be trimmed, the trim must be performed external to the device. Figure 3c shows an optional connection for positive inputs in which R R add a variable resistance in series with R OFF2 source of 0.6 V applied to R then adjusts the offset 1 mV ...
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... The FS input should then be applied and the gain pot should be adjusted until the desired FS frequency is indicated. INPUT PROTECTION The AD654 was designed to be used with a minimum of additional hardware. However, the successful application of a precision IC involves a good understanding of possible pitfalls and the use of suitable precautions ...
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... Pin 1 goes low. The peak level of this additional cur- L rent causes Q1 to saturate, and thus regenerates the AD654’s output square wave at the collector. The supply voltage to the AD654 then consists level, less the resistive line drop, plus a one V p-p square wave at the output frequency of the AD654. BE This ripple is reduced by the diode/capacitor combination ...
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... Figure 11 shows the AD654, with a full-scale input voltage and a full-scale output frequency of 100 kHz, connected to the timer/counter input Pin T1 of the 8048. Such a system can also operate on a single +5 V supply. The 8748 counter is negative edge triggered ...
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... P20 that is greater than the AD654 supply voltage. PORT 2 8048 Resistors R1–R3 are used to scale the +10 V input voltage P27 down seen at Pin 4 of the AD654. Recall that V must be less than V DB0 IN BUS The timing resistor and capacitor are selected such that this 0 V ...
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... MHz or more. The designer may take advantage of this feature in order to operate the device at frequencies in excess of 500 kHz. Figure 13 illustrates this with a circuit offering 2 MHz full scale. In this circuit the AD654 is operated at a full scale (FS mA, with 100 pF. This achieves a basic device FS frequency ...
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... PLANE 0.014 (0.356) 0.045 (1.15) 8-Lead SOIC (SO-8) (Narrow Body) 0.1968 (5.00) 0.1890 (4.80 0.1574 (4.00) 0.2440 (6.20) 0.2284 (5.80) 0.1497 (3.80 PIN 1 0.0500 (1.27) BSC 0.0688 (1.75) 0.0532 (1.35) 0.0192 (0.49) 0.0098 (0.25) SEATING 0.0138 (0.35) PLANE 0.0075 (0.19) –11– AD654 0.195 (4.95) 0.115 (2.93) 0.015 (0.381) 0.008 (0.204) 0.0196 (0.50 0.0099 (0.25) 8 0.0500 (1.27) 0 0.0160 (0.41) ...