Post on 13-Jan-2016
transcript
Robocon 2007, Hong Kong University of Science & Technology
Robocon 2007Electronics Quickstart!
Robocon 2007Electronics Quickstart!
Session 2 PreludeLogic
Prepared by KI Chi Keung [chikeung @ ust.hk]
WONG Long Sing (Sam) [sam @ hellosam.net]
Robocon 2007, HKUST
Table of Contents
1. MOSFET1. NMOS
2. PMOS
3. CMOS
2. Buffer
3. MCU Application
Robocon 2007, HKUST
NMOS
Symbol Physical Cross SectionSee Wikipedia, MOSFET
Gate
Source
Drain
Robocon 2007, HKUST
NMOS
VGS < Vth
Cut-off ModeVth = Thershold Voltage ≈ 1.5V (Model dependent)
IDS = 0
Gate
Source
Drain
Robocon 2007, HKUST
NMOS
VGS > Vth
Linear Mode
VDS > VGS - Vth
IDS will be large
Gate
Source
Drain
Robocon 2007, HKUST
PMOS
Symbol
Gate
Drain
Source
Robocon 2007, HKUST
PMOS
VGS < Vth
Cut-off ModeVth = Thershold Voltage ≈ -1.5V (Model dependent)
IDS = 0Gate
Drain
Source
Robocon 2007, HKUST
PMOS
VGS < Vth
Linear Mode
VDS < VGS - Vth
IDS will be largeGate
Drain
Source
Robocon 2007, HKUST
MOS
Other commonly seen schematic symbolsSee Wikipedia, MOSFET
N-channel
P-channel
Robocon 2007, HKUST
CMOS - Inverter
Source
Drain
• Not a new type of MOS, but • It means combining the use of PMOS and
NMOS to form interesting logic circuit
Output
Source
Input
Robocon 2007, HKUST
CMOS - Inverter
Symbol
OutputInput
Robocon 2007, HKUST
CMOS - Inverter
Input High, Output Low
5V
0V
0V5V
Robocon 2007, HKUST
CMOS - Inverter
Input Low, Output High
5V
0V
5V0V
Robocon 2007, HKUST
Buffer
Symbol
Logically same as two inverters in serial
OutputInput
OutputInput
Robocon 2007, HKUST
Buffer
5V
0V
5V
0V
0V0V
Robocon 2007, HKUST
Buffer
5V
0V
5V
0V
5V5V
Robocon 2007, HKUST
Buffer
With an appropriate buffer, we get a…
• Low impedance output
• Strong output
• Good output
• Internal resistance of the power source is low
regardless of the input impedance.
Robocon 2007, HKUST
Buffer with Enable
Symbol
OutputInput
Enable
Robocon 2007, HKUST
Buffer with Enable
OutputInput
Enable
Transmission Gate
Robocon 2007, HKUST
Buffer with Enable
5V5V
5V
Robocon 2007, HKUST
Buffer with Enable
0V0V
5V
Robocon 2007, HKUST
Buffer with Enable
Floating
Hi-Z
Hi-Impedance
< 5V + Vth
> 0V - Vth
5V
0V
Robocon 2007, HKUST
MCU Application
Device A Device B
PORT
DDR
PORT
DDR
Robocon 2007, HKUST
MCU Application
Device ADDR = 1
PORT = 0
Device BDDR = 1
PORT = 0
0V
5V
0V
5V0V
Robocon 2007, HKUST
MCU Application
Device ADDR = 1
PORT = 0
Device BDDR = 0
0V
5V
X
0V0V
Robocon 2007, HKUST
MCU Application
Device ADDR = 1
PORT = 1
Device BDDR = 1
PORT = 0
5V
5V
0V
5V~2.5V
Robocon 2007, HKUST
MCU Application
Device ADDR = 0
Device BDDR = 0
X
0V
X
0VX
Robocon 2007, HKUST
MCU Application – Pull Up
Device A Device B
PORT
DDR
PIN
PORT
DDR
PIN
DDR | ~PORT DDR | ~PORT
Robocon 2007, HKUST
MCU Application – Pull Up
Device ADDR = 0
PORT = 0
Device BDDR = 0
PORT = 0
0V
0V
X
0V
0V
X
5V 5V
X
Robocon 2007, HKUST
MCU Application – Pull Up
Device ADDR = 0
PORT = 1
Device BDDR = 0
PORT = 0
0V
0V
1
5V
0V
1
0V 5V
5V
Robocon 2007, HKUST
MCU Application – Pull Up
Device ADDR = 1
PORT = 0
Device BDDR = 0
PORT = 0
0V
0V
0
0V
5V
0
5V 5V
0V
Robocon 2007, HKUST
MCU Application – Pull Up
Device ADDR = 1
PORT = 1
Device BDDR = 0
PORT = 1
5V
0V
1
5V
5V
1
5V 0V
5V
Robocon 2007, HKUST
MCU Application – Pull Up
Device ADDR = 1
PORT = 0
Device BDDR = 0
PORT = 1
5V
0V
0
0V
5V
0
5V 0V
0V
Robocon 2007, HKUST
MCU Application – Pull Up
Device ADDR = 1
PORT = 1
5V
5V
1
5V
5V
Robocon 2007, HKUST
MCU Application – Pull Up
Device ADDR = 1
PORT = 1
5V
5V
X
5V
Tends to 0V
Robocon 2007, HKUST
MCU Application – Pull Up
Device ADDR = 0
PORT = 1
5V
0V
1
0V
5V
Robocon 2007, HKUST
MCU Application – Pull Up
Device ADDR = 0
PORT = 1
5V
0V
0
0V
0V