Week #4: Discussion results OTAs and case study Group #33 Group member: Tianhao Han Ximeng Sun(Susie) Xing Cao(Star) Zhuoran Yang

Why there is no high input voltage OTAs?

Strengths of an OTA Have a high work frequency. Have a not complicated circuit to build.

What are the applications of OTAs?

Use OTA to build a Filter

Use OTA to build a Filter Where gain can be changed by the inner current.

Strengths of a filter composing with OTAs Have a low power consumption. Have a good thermal stability. Have a small chip area. Easy to integrate.

What does filters use for?

Filters ---------Electronic Filters Electronic filters are used to prevent certain electronic frequencies from passing from one region of an electronic circuit to another region of that circuit. Electronic filters generally perform one of three functions: allowing certain electrical frequencies to pass through the filter, blocking certain frequencies from passing through the filter and completely blocking direct current electrical energy.

Applications of electronic filters Band-pass Filters Band-stop Filters DC Blocker Filters Read more: Uses of Electronic Filters | eHow.com http://www.ehow.com/list_7169347_uses-electronic- filters.html#ixzz27XK7yeXr

Filters in real world 1, Car devices 2, Electronic data processing and office equipment 3, Drive and control equipment 4, Automatic control equipment 5, Elevator and lifting equipment 6, Military equipment 7, Telecommunication device 8, Power generation and power supply 9, Machinery manufacturing equipment 10, Building automation 11, Household appliances

Why there is no high input voltage OTAs?

Why there is no high input voltage OTAs? Have a larger area. Cost more. Have a bad thermal stability.

Why there is no high input voltage OTAs? Main reason might be: Have more power consumption.

We “imagine” we are Marketing Engineer And we do our own case!

Smaller, smarter, colorful…………….but…..

Quiz Time! Do you have a smart phone? Y/N Do you charge your phone every single day? Y/N Do you have the issue that when you need to use cell phone but it is out of battery? Y/N Do you want to charge your phone when you are outside? Y/N

Why don’t we use a solar to charge our cell phones!

Good News!!! ----Some good news about using solar energy and produce

Solar cell efficiency Eff = (Im*Vm)/(S*Pin) Lm– Maximum current A; Vm– Maximum voltage V S– Effective area of solar module m^2 Pin– input power of sunlight W/m^2

advantage Efficient: Normally 15% China: 17% (Shang De) MAX: 25% From 1972 to 1997, scientist decline the price about make solar battery from $50 per W to $ 5 per W 2008 Rensselaer Polytechnic Institute (RPI) Produce: A new antireflective coating (only 3.79% of the Sunlight was reflected and unhavested) advantage Environment-friendly product Save money Use the natural source Sunshine almost exit in everywhere An sustainable energy & renewable energy sources

USD $70

USD $18 Product in China Power: 1.3W Solar battery: 5.5V 200mA Battery capacity: 4000mAh Input voltage: 400~800mA (max: 1.2A) Output voltage: 5V, 9V 120*75*12mm Weight: 156g Charging time(to cellphone): 120min Charging time(to inner battery): 18~20h USD $18

Compare Weight: 65g 156g Price: $70 $18 Battery capacity: 1500mAh Charging time(to inner battery): 8h 18~20h

BAD NEW?! ------Some technology limit and weak about solar energy and solar products

1:limitation 2:portability 3:fungible Disadvantage 1:limitation 2:portability 3:fungible

Limitation Weather limitation under the sun. Gender limitation under bright light. Gender limitation

Portability Weight: solar charger--- 65g-850g cell phone ----- iphone 5 112g Nokia n8 00 135g Samsung Galaxy S III 133g

Fungible 1 :Car charger 2: Backup battery 3: Original charger 4: Portable charger

Portable charger

It should has a big market! Conclusion Cost ($50) Awareness (advertisement) portable (65g) Reputation(reliable) (free to use) It should has a big market!

Question time.

Thank you for your listening!