The present invention provides a passive RFID chip with on-chip charge pumps
for generating electrical power for the chip from radio frequencies. The passive
RFID chip comprises an analog portion and a digital portion. The analog portion
primarily comprises a voltage sensor and an AM data detector. The digital portion
comprises a state machine digital logic controller. Incoming RF signals enter the
chip via external antennas. The RF signals are converted into regulated DC signals
by RF-DC converters with the voltage sensor. The RF-DC converters provide power
for all the on-chip components and hence the chip does not require external power
supply. The incoming RF signals are demodulated by demodulators and enter the AM
data detector where the envelope transitions are detected. A voltage alarm is provided
to ensure the voltage level does not drop below an operational level of the chip.
The logic signals and programming data are controlled by the state machine digital
logic controller and the timing signals are provided by an on-chip oscillator.