70009 Parallax Inc, 70009 Datasheet - Page 115

• Manufacturer Part Number: 70009
• Description: BOOK UNDERSTANDING SIGNALS
• Manufacturer: Parallax Inc
• Type: Signal Analysisr

Specifications of 70009

• Style: Book
• Title: Understanding Signals
• Contents: Guide to Generate, View and Measure Wave Forms
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• Other names: 70009PAR

Recall that the gain for a non inverting amplifier is:
Gain = 1 + Rf/Ri
If Ri is 2 kΩ and Rf is 1 kΩ, the gain will be:
Gain = 1 + 1000/2000
This means that the amplitude of the signal at the amplifier’s output (measured by
OPTAscope CH2) will be 1.5 times the amplitude of the signal supplied to the amplifier’s
input (OPTAscope CH1). If Ri is 1 kΩ and Rf is also 1 kΩ, the gain will be:
Gain = 1 + 1000/1000
= 1 + 0.5
= 1.5
P15
P14
P13
P12
P11
P10
P9
P8
P7
P6
P5
P4
P3
P2
P1
P0
X2
X3
Rf
Vdd
Vin
Ri
Vss
Figure 8-9:
Non-inverting op-
amp circuit wiring
diagram, with Ri
and Rf labels
Note: If using the
HomeWork
Board, replace
the 220 Ω resistor
with a jumper
wire. A 220 Ω
resistor is already
built into the
board.