Wireless data and Wireless data and powerpower

Brian McKinney

Michael Vincent

What we are doing Ultimate goal is to create a device capable of precisely

stimulating tissue in-vivo without connection to outside Lack of external connection implies IC needs to derive

both power and data from RF signal

Test Bench

Not a mixed signal IC but needed for simulation and testing purposes

Generates random data Frames random data (e.g. start/stop and parity

bits) Modulates carrier (ASK) with framed data

Regulator

“Buck” type step down switching regulator

Ramp Generator

Comparator

Switch Side

SpecificationsTarget Actual

Vin (V) 5 – 8 ~4.5 – 7

Vout (V) 3.3 ~3.3

Power (mW) 25 ~40

Efficiency (%) 50 ~73

Fs (kHz) 100 50

C (uF) 10 .5

L (uH) 1 1

Results

Data Path

Envelope Detector

Input: AM Signal (4MHz)

Output: 100 Kbps “Dirty Data”

Clock Recovery

Input: 100 Kbps “Dirty Data”

Output: 100 KHz Synchronous Clock

Timing Control

Inputs: 100 Kbps “Dirty Data”100 KHz Clock

Outputs: Clean Clock, Clean Data, Frame Strobe

Behavioral Simulation

Bandpass Filter

Delay-Lock Loop

PLL Theory

FVCOPD

FVCOPD

data

clk

KKKs

KKKsH

)(

Vsrad

VDD

ffK

sRCK

VDDK

VCO

F

PD

319,8

1

1

radV 1.0504

minmax

RCKK

RCs

s

RCKK

sHVCOPD

VCOPD

data

clk

2

)(

65.02

1

2.12

n

nL

VCOPDn

RC

msTRCN

KK

Phase Detector Operation

clk = 0

data = 0

Vout VDD

clk = 0

data = -(¾)

Vout (¼)VDD

clk = /2

data = 0

Vout (½)VDD

VCO•Current Starved VCO

•Vout-filter range: 0 – VDD

•fmin = 90 kHz

•fmax = 105 kHz

•(½)VDD ftyp = 100 kHz

Full Data Path Simulation

Conclusions and Q&A