130-28176 Parallax Inc, 130-28176 Datasheet - Page 203

• Manufacturer Part Number: 130-28176
• Description: KIT PARTS PROCESS CONTROL
• Manufacturer: Parallax Inc

Specifications of 130-28176

• Accessory Type: Education Kit
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: Board of Education Full Kit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant

With no gain, or actually a gain of 1 or unity gain, the voltage to the ADC is the voltage
sensed at the ADC. When the op-amp is used with a gain of 4, an input voltage of 1.25 V
will provide 5 V to the ADC. Note the slope of the line:
The slope of the line is also the gain, giving a line equation of:
What is the resolution of the circuit now? In comparing the applied voltage to the bit
count: 1.25 V/255 = 0.0049 V/bit value. In terms of temperature:
...which is 4 times the resolution previously measured.
m = ∆Output/∆Input = (5−0)/(1.25−0) = 5/1.25 = 4
VADC = 4(ADC-IN) + 0
125 °F/255 = .49 °F/bit value
Figure 6-8
Vin vs. ADC
Voltages