Created By: Hussein Nosair

Source: Polygons Pours & Copper Regions

* A copper pour on a signal layer is a common part of a PCB design.

* Hatched pour is used for ground plains in an analog design.

* Solid pour is used for carrying heavy currents.

* Solid pour is also used for ground plains meant for EMC shielding.

Created By: Hussein Nosair

Pin Configurations of the Microchip 40-pin families

1 Instruction Cycle = 4 pulses

1 Instruction Cycle = 4 clocks

Created By: Hussein Nosair

	PIC16F877	PIC18F4520
PIN NUM.	PIN NAME	PIN NAME
1	MCLR/VPP	MCLR/VPP/RE3
2	RA0/AN0	RA0/AN0
3	RA1/AN1	RA1/AN1
4	RA2/AN2/VREF-/CVREF	RA2/AN2/VREF-/CVREF
5	RA3/AN3/VREF+	RA3/AN3/VREF+
6	RA4/T0CKI/C1OUT	RA4/T0CKI/C1OUT
7	RA5/AN4/SS/C2OUT	RA5/AN4/SS/HLVDIN/C2OUT
8	RE0/RD/AN5	RE0/RD/AN5
9	RE1/WR/AN6	RE1/WR/AN6
10	RE2/CS/AN7	RE2/CS/AN7
11	VDD	VDD
12	VSS	VSS
13	OSC1/CLKI	OSC1/CLKI/RA7
14	OSC2/CLKO	OSC2/CLKO/RA6
15	RC0/T1OSO/T1CKI	RC0/T1OSO/T13CKI
16	RC1/T1OSI/CCP2	RC1/T1OSI/CCP2
17	RC2/CCP1	RC2/CCP1/P1A
18	RC3/SCK/SCL	RC3/SCK/SCL
19	RD0/PSP0	RD0/PSP0
20	RD1/PSP1	RD1/PSP1
21	RD2/PSP2	RD2/PSP2
22	RD3/PSP3	RD3/PSP3
23	RC4/SDI/SDA	RC4/SDI/SDA
24	RC5/SDO	RC5/SDO
25	RC6/TX/CK	RC6/TX/CK
26	RC7/RX/DT	RC7/RX/DT
27	RD4/PSP4	RD4/PSP4
28	RD5/PSP5	RD5/PSP5/P1B
29	RD6/PSP6	RD6/PSP6/P1C
30	RD7/PSP7	RD7/PSP7/P1D
31	VSS	VSS
32	VDD	VDD
33	RB0/INT	RB0/INT0/FLT0/AN12
34	RB1	RB1/INT1/AN10
35	RB2	RB2/INT2/AN8
36	RB3/PGM	RB3/AN9/CCP2
37	RB4	RB4/KBI0/AN11
38	RB5	RB5/KBI1/PGM
39	RB6/PGC	RB6/KBI2/PGC
40	RB7/PGD	RB7/KBI3/PGD

]]> http://circuitnegma.wordpress.com/2008/06/18/pin-configuration-pic16f877-40pins-vs-pic18f4520-40pins/feed/ 0 circuitnegma http://circuitnegma.wordpress.com/2008/06/12/glossary-2-sidactor/ http://circuitnegma.wordpress.com/2008/06/12/glossary-2-sidactor/#comments Thu, 12 Jun 2008 14:07:38 +0000 Circuit Negma http://circuitnegma.wordpress.com/2008/06/12/glossary-2-sidactor/ ]]>

Created By: Hussein Nosair

VDRM (Peak Off-state Voltage) : Maximum voltage that can be applied while maintaining OFF state.

IDRM (Leakage Current) : Maximum peak OFF-state current measured at VDRM (Peak OFF-state Voltage).

VS (Switching Voltage) : Maximum voltage prior to switching to ON state.

IS MAX (Switching Current) : Maximum current required to switch to ON state.

VT MAX (ON state Voltage) : Maximum voltage measured at rated ON state current.

IH MIN (Holding Current) : Minimum current required to maintain ON state.

CO MIN (Minimum OFF-state Capacitance) : Minimum capacitance measured in OFF state.

CO MAX (Maximum OFF-state Capacitance) : Maximum capacitance measured in OFF state.

IPP (Peak Pulse Current) : Maximum rated peak impulse current.

ITSM (Peak One-cycle Surge Current) : Maximum rated one-cycle AC current.

di/dt MAX (Rate of Rise of Current) : Maximum rated value of the acceptable rate of rise in current over time.

Switch to ON STATE :

V <= VS @ I <= IS MAX

Maintain ON STATE :

Von <= VT MAX @ Ion >= IH MIN

OFF STATE :

V <= VDRM @ I <= IDRM

Created By: Hussein Nosair

VDRM = maximum repetitive peak-off state voltage
VRRM = maximum repetitive peak reverse voltage
ITGQM = maximum repetitive controlable on-state current
Cs = snubber capacity
IT(RMS) = RMS on-state current
ITAVm = maximum average on-state current (50 Hz half sine wave)
ITSM = maximum surge on-state current, nonrepetitive (50 Hz half sine wave)
(diT/dt)cr = critical rate of rise of on-state current
(dvD/dt)cr = critical rate of rise of off-state voltage
I2t = maximum rated value I2t
VTM = peak on-state voltage
VTO = threshold voltage
rT = slope resistance (on-state)
IGT = gate trigger current
VGT = gate trigger voltage
tGQ = turn-off time
TjM = maximum junction temperature
Tj = junction temperature = TjM unless otherwise indicated
Tc = case temperature
m = mass
Fp = pressure force

Electrical Design Factors

Conductor Capacitance

C = 0.31 a/b + 0.23(1 + k) log10 (1 + 2b/d +2b + b²/d²)

Where
k = Substrate dielectric constant
a = Conductor thickness
b = Width of conductor in inches
d = Distance between conductors in inches

Conductor Resistance

R = 0.000227W

Where
W = Width of conductor

Characteristic Impedance

Zo = R + jwL / G + kwC

Where
Zo = Apparent Z of an infinitely long line in ohms
R = Resistance in ohms
L = Inductance in Henries
G = Conductor per unit length of line in mhos
C = Capacitance in farads

Characteristic Impedance for a Micro Strip

Zo = (h/W) (377 / (Sqrt. e_r) {1 + (2h/PI W)[1 + ln(PI W/h)]}

Where
h = Dielectric thickness
W = Micro Strip width
e_r = Effective dielectric constant of substrate

A switching-mode power supply is a power supply that provides the power supply function through low loss components such as capacitors, inductors, and transformers — and the use of switches that are in one of two states, on or off. The advantage is that the switch dissipates very little power in either of these two states and power conversion can be accomplished with minimal power loss, which equates to high efficiency. The term switchmode was widely used for this type of power supply until Motorola, Inc., who used the trademark SWITCHMODE TM for products aimed at the switching-mode power supply market, started to enforce their trademark. Then more generic terms had to be found. I started using the term switching-mode power supply to avoid infringing on the trademark. Others used the term switching power supply, which seems to be the more popular term. PSMA does not define either switching-mode power supply or switching power supply, but does define switching regulator.

Switching-mode power supply design tutorial by Jerrold Foutz