1. FAN5355 – 800mA/1000mA 3MHz I2C Digitally Programmable Regulator
Product Guide
Peter Khairolomour, Aug, 11, 2010

2. More and more processors (CPUs) in portables
Analog BaseBand Processor (BB)
Keyboard controller
Bluetooth transceiver with baseband processor
Graphics Processing Unit (GPU)
Digital Base Band Processor with Main Central Processor (CPU) and Digital Signal Processor (DSP)
Image Sensor Processor (ISP)

3. More and more processors (CPUs) in portables
Your cellphone is getting smarter and smarter: 10 processors execute various tasks to support more and more features:
Higher definition image sensor
Better graphics
More wireless interfaces (Bluetooth, GPS, WiFi,…)
3G connectivity
USB 2.0 interface
MP3 storage and playback
MultiMedia support
High end audio, etc…
But how can we keep on managing the power to these hungry processors?

4. CPU power consumption
-The faster the processor clock frequency, the higher the power consumption
-A higher supply voltage will increase the Power quadratically

5. Power saving through DVS
To save power, the clock frequency of the processor is modulated as a function of the intensity of the computing task that the CPU has to execute.
System designers lower the frequency through the Operating System for computing tasks that are less intensive, but …
Frequency Adjusting is not enough, much more power can be saved by modulating the Vsupply while adjusting the frequency. This is called Dynamic Voltage Scaling.
We can lower the voltage for less compute intensive tasks (slowed down processors) and increase the voltage for more demanding compute tasks that require a higher CPU clock frequency.
As an example (remember P=FV2):
If we Lower the CPU clock frequency by 10% from 1000MHz to 900MHz and the supply voltage also by 10% from 1.5V to 1.35V, then we reduce the power consumption by 27%! (=(1-0.1)*(1-0.1)^2)

6. FAN5355 is a DVS buck
The FAN5355 can output different Vout values (= DVS) ranging from 0.75V – 1.975V by programming internal registers through a serial interface ( I2C bus).

7. Is the FAN5355 the only DVS buck?
No, but we have the best one !
Best-In-Class transient response while consuming Lowest-In-Class quiescent current and providing highest efficiency.
Pin-to-Pin Compatible with TPS6235X from Ti
but with much better performance... FAN5355 is superior in Iq, transient response and efficiency.

8. Efficiency: FAN5355 vs. TPS62350
We beat TI by 8% !

9. Transient Response: FAN5355 vs. TPS62350
load transient 50mA to 400mA
VOUT=1.35V, 20mV/div
VIN=3.6V
TPS62350
delta VOUT = ~28mV
delta VOUT = ~38mV
TI can’t handle the load

10. FAN5355 – 800mA/1000mA 3MHz I2C Digitally Programmable Regulator
What
37µA Typical Quiescent Current
Up to 92% Efficiency
Best-in-Class Load Transient
3MHz Fixed-Frequency Operation
option for Synchronizing to External Clock Signal
800mA or 1000mA Output Current
I²C Compatible Interface up to 3.4Mbps
Dynamic voltage scaling: 0.75V – 1.975V VOUT range
Pin-Selectable Output Voltages
±2% DC Voltage Accuracy
2.7V to 5.5V Input Voltage Range
Synchronous Operation
Auto Mode with Pulse Skip Power Save or Force PWM
UVLO, SCP, and TSD protection
WLCSP 12-bump 0.5mm pitch, 1.46 x 2.23mm
MLP 6-lead, 3 x 3mm
Where
Core processors, graphics processors, and application processors that can benefit from DVS (Dynamic Voltage Scaling). FAN5355 offers fast transient response, low quiescent current, small foot print, high efficiency, and adjustable output voltage.
GoForce5500tm nVIDIA GPU Core power / IMAGEONtm ATI Media Co-processor power
SmartReflex™ Compliant Power Supply
Split Supply DSPs and P Solutions OMAP™, XSCALE™
Who
Cellular: Motorola, Nokia, Pantech Curitel, Samsung, LG, SonyEricsson, RIM, Kyocera, Qualcomm, EMP
MP3/PMP: Apple, iRiver, Sony, Creative Labs, Archos
GPS Navigation: TomTom, Garmin, Lowrance, Magellan, Averatec
Network Cards: Option, Netgear, Kyocera, Fujitsu, Huawei
Competition: TPS6235X (pin-to-pin compatible)
How
Performance – fast transient and low quiescent current, high efficiency
Small Foot Print – 12 bump pin CSP or 6 lead MLP and tiny 1uH inductor
Low Cost – minimal external components (3)
Pin-to-Pin Compatible
with TPS6235X

11. Value proposition Best performance Alternative source Small formfactor
Fast I2C interface
Fast time to market through app notes, eval boards,…

12. How to position and sell FAN5355?
The FAN5355 was developed specifically for powering core, graphics, and application processors in handheld applications where footprint, efficiency, and performance are all simultaneously paramount. The most compelling feature of this new part is its ability to adjust the output voltage dynamically lending itself to be used in systems architected for DVS (Dynamic Voltage Scaling).
FAN5355 is pin-to-pin compatible with the TPS FAN5355 however provides faster transient response while consuming lower quiescent current. Specifically, the quiescent current on this device is 37uA. Load transient response during a step of 50 to 450mA is a remarkable 28mV. Another key attribute of this new architecture is that it smoothly transitions from light load mode to full load mode with no output "bump".
Perhaps most amazing though is the class-leading efficiency of up to 92% which is possible due to careful optimization of the control system and power train.

13. Who are the customers/applications that you should target?
Where
Core processors, graphics processors, and application processors that can benefit from DVS (Dynamic Voltage Scaling). FAN5355 offers fast transient response, low quiescent current, small foot print, high efficiency, and adjustable output voltage. Some examples include…
-GoForce5500tm nVIDIA GPU Core power
-IMAGEONtm ATI Media Co-processor power
-SmartReflex™ Compliant Power Supply
-Split Supply DSPs and P Solutions OMAP™, XSCALE™
Who
Cellular: Motorola, Nokia, Pantech Curitel, Samsung, LG, SonyEricsson, RIM, Kyocera, Qualcomm, EMP
MP3/PMP: Apple, iRiver, Sony, Creative Labs, Archos
GPS Navigation: TomTom, Garmin, Lowrance, Magellan, Averatec
Network Cards: Option, Netgear, Kyocera, Fujitsu, Huawei

14. Design-In support FAN5355 Datasheet
FAN5355 Product Overview
Evaluation Boards
Request via Sales Center or Contact Product Line
Samples
Contact product line

15. Contacts Marketing contacts Application support
Cell phones and data cards
Peter Khairolomour
All other customers
Stephen Stella
Application support
Steve Cartier

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