1. Presented by Paul Kasemir and Eric Wilson
Chapter 11 Fundamentals of Passives: Discrete, Integrated, and Embedded
Presented by
Paul Kasemir and Eric Wilson

2. Chapter Objectives Define passives and their fundamental parameters
Describe the role of passives in electronic products
Introduce the different forms
Describe the different materials and processes used for passives

3. 11.1 What are Passives?
Can sense, monitor, transfer, attenuate, and control voltages
Cannot differentiate between positive and negative polarity
Cannot apply gain or amplification
Passives absorb and dissipate electrical energy
Ex. Resistor, inductor, capacitor, transformer, filter, switch, relay

4. 11.2 Role of Passives in Electronic Products
High frequency applications take smaller values (pF and nH)
Impedance matching to coax (50 ohm)
Power supplies require large capacitance
Digital circuitry requires decoupling capacitors for current surges
Resistors used for termination, filtering, timing and pull up/down

5. RF Passives
Filters, couplers, RF crossings, impedance matching, and antennas.
Signal inductors (1-20nH) and capacitors (1-20pF)
Choke Inductors (20-100nH)
Higher frequency requires smaller footprints, or even embedded passives
Mixed-Signal packages used in cell phones and GPS in MCM

6. 11.3 Fundamentals of Passives
Resistor
Resist current flow
Dissipate a power as heat
V = IR
Current Density, resistivity, conductivity, and sheet resistance

7. Fundamentals of Capacitor
Stores electrical charge Q
Dielectric between 2 metal plates
Capacitance C = QV = εA/d
I = C(dV/dt) DC open
Series and parallel capacitors
Reactance, impedance, ESR, leakage current

8. Fundamentals of Inductor
Stores energy in magnetic field
Wire coil with or without core
Inductance L = μn2Al
V = L(dI/dt) DC short
Magnetic cores increase B field, and thus inductance

9. Filters Low-pass High-pass Bandpass Bandstop
Series-parallel combination of R, L, and C

10. 11.4 Physical Representation

11. Physical Representation
Discrete – single passive
Integrated – multiple passives
Array
SIP and DIP resistor packages
Network
Filter circuits with only inputs and outputs as package terminals
Embedded
Created as part of the substrate

12. Passive Comparisons
In a typical circuit, 80% of components are passives
50% of the PCB is taken by passives
25% of solder connections go to passives
~900 billion discrete units per year

13. 11.5 Discrete Passives Resistors Wire-wound Film resistors
Nichrome wire
Film resistors
Carbon or metal film deposited on substrate
Carbon-composite
Graphite powder, silica and a binder

14. Resistor applications
Bias
Divider
Feedback
Termination
Pull up/down
Sense
Delay
Timing

15. Polar Capacitors Aluminum electrolyte Tantalum
Uneven surface gives efficiency
Tantalum
Pellet with lots of surface area
Cathode material limits conductivity

16. Nonpolar Capacitors Film Ceramic High Capacitance Rolled Stacked
Most dominant
Like stacked film
Used to need precious metals
Now Ni and Cu can be used
High Capacitance
1-47 F

17. Capacitor Performance I
Remember capacitors have AC effects
Temperature coefficient
Typically less than 10%
Some can be on order of ppm/°C
Larger capacitance = worse coefficient

18. Capacitor Performance II
Voltage coefficient
Aging
Logarithmic
X7R 1% per decade hour (good)
Reversible

19. Capacitors Becoming Inductors
Caps have associated inductance
Self resonant frequency
ESL dependent on physical structure

20. Capacitor Applications I
Coupling
Timing and wave shaping
Changing RC time constant
Windshields

21. Capacitor Applications II
Filtering
Low pass filters
Decoupling
Mostly for digital signals

22. Inductors SMT inductors looking like SMT caps Core type
Value in henries, but should also have series resistance
“Choke” role
Timing circuits using Ls are gone

23. 11.6 Integrated Passives Increased quantity decreases price
But maybe not as much as you would think
Smaller components = higher mounting costs
But maybe a lot more than you would think

24. Arrays and Networks Arrays Networks
Many of the same type in a single package
Good for R
Not as much for C
Networks
Different types in one package
Good for RC or RLC functions

25. 11.7 Embedded (Integral) Passives
Benefits
Smaller
Cheaper (???)
More reliable
Costs
New designs
New manufacturing processes

26. Integration Options
Ceramic
Thin film on Si
IC Integration
Horrible

27. Barriers to Embedded Passives
Risk
No reworkability
Cost
But wait until 2004!

28. Embedded Passives TechnologyR
Thick film ~100-1M Ω/square
Thin film ~ Ω/square C
Typical inorganic is 50 nF/cm2
GE has gotten ~200 nF/cm2 with inorganics
Polymer-ceramic components can get 4-25 nF/cm2 L
Okay in embedded if <100 nH
Discrete recommended for >100 nH

29. The End