UC Berkeley

DAC Student Design CompetitionDAC Student Design Competition

Shaker

15mahNiMH

< 200mvbias

1.0 - 1.4v

2.0 – 2.8v

chargepump

radio PA power enable

analog switch

0.65v

1.0vRadio digital power(GPIO pin)

MSP430uC

SPI serial IF

Wakeup

JTAG external IF

TPMSSensor

powerswitches

SPI VDD

Tx VDD

SPI serial IF

Tx datalevel

shifters

Interface

radio

RF

SPI pwr on/off

PA pwr on/off

SPI serial IF

Tx data

Sensor/Digital

shunt reg.

linearregulator

“Picocube: A 1cm3 Sensor Node Powered by Harvested Energy”Yuen-Hui Chee, Mike Koplow, Michael Mark, Nathan Pletcher, Mike Seeman, Fred Burghardt,

Dan Steingart, Jan Rabaey, Paul Wright, Seth Sanders

UC Berkeley

Cube AnatomyCube Anatomy

• Stacked PCBs

• 1cm square

uC boardtop/bottom

sensor board #1top/bottom

ona

dime

radio boardtop/bottom

switch/power boardtop/bottom

storage boardtop/blank bottomsensor board #2

top/bottom

radio COB die

UC Berkeley

Custom TechnologyCustom Technology

• Custom PicoCube Transmitter w/ FBAR– 10 kbps, 10 m range at 0

dBm– Supports FSK modulation,

but useful for OOK– Custom 200Ω antenna,

matching PA

• Power Management IC– 2 switched-capacitor

converters (0.7V, 2.1V)• 84% efficient

– Synchronous Rectifier• 88% efficient from shaker

– Ultra-low-power references and other circuitry