3.0 ADC081S051 TRANSFER FUNCTION

The output format of the ADC081S051 is straight binary. Code transitions occur midway between successive integer LSB values.

The LSB width for the ADC081S051 is V

code of 0000 0000 to a code of 0000 0001 is at 1/2 LSB, or a voltage of V

4.0 TYPICAL APPLICATION CIRCUIT

A typical application of the ADC081S051 is shown in Figure

6. Power is provided in this example by the National Semi-

conductor LP2950 low-dropout voltage regulator, available in

a variety of fixed and adjustable output voltages. The power

supply pin is bypassed with a capacitor network located

close to the ADC081S051. Because the reference for the

ADC081S051 is the supply voltage, any noise on the supply

will degrade device noise performance. To keep noise off the

supply, use a dedicated linear regulator for this device, or

provide sufficient decoupling from other circuitry to keep

noise off the ADC081S051 supply pin. Because of the

ADC081S051’s low power requirements, it is also possible to

use a precision reference as a power supply to maximize

performance. The four-wire interface is also shown con-

nected to a microprocessor or DSP.

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FIGURE 5. Ideal Transfer Characteristic

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FIGURE 6. Typical Application Circuit

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