V4070 EM Microelectronic, V4070 Datasheet - Page 7

• Manufacturer Part Number: V4070
• Description: Crypto Contactless Identification Device
• Manufacturer: EM Microelectronic

Write Word
Power On Reset
When the V4070 with its attached coil will enter an
electromagnetic field, the built in AC/DC converter will
supply the chip. The DC voltage is monitored and a
Reset signal is generated to initialise the logic. The
power On Reset is also provided in order to make sure
that the chip will start issuing LIWs and be ready to
accept commands with a sufficient DC power level. A
hysteresis is provided to avoid improper operation at
limit level.
OUTPUT
Write Word
INPUT
Command
Receive
Receive
Address
Receive
Begin
Data
EM MICROELECTRONIC-MARIN SA
LIW
RM WRITE WORD ADDRESS
valid ?
Send
Write
Send
Data
End
ACK
ACK
Y
N
Send
NAK
Figure 13
DATA
T
wa
AC/DC Converter and Voltage Limiter
The AC/DC converter is fully integrated on chip and
will extract the power from the incident RF field. The
internal DC voltage will be clamped to avoid high in-
ternal DC voltage in strong RF fields.
Clock Extractor
The Clock extractor will generate a system clock with
a frequency corresponding to the frequency of the RF
field. The system clock is fed into a sequencer to gen-
erate all internal timings.
The clock extractor is optimized for power-consump-
tion, sensitivity and noise-suppression. As the input
signal is subject to a large dynamic range due to the
amplitude modulation, the clock-extractor may miss
clocks or add spurious clocks close to the edges of
the RF-envelope. This desynchronisation will not be
larger than
account when developping reader software.
Data Extractor
The transceiver generated field will be amplitude modu-
lated to transmit data to the V4070. The Data extrac-
tor demodulates the incomming signal to generate logic
levels, and decodes the incomming data.
Modulator
The Data Modulator is driven by the serial data
outputted from the memory or the Crypto-Logic which
is Manchester encoded. The modulator will draw a
large current from both coil terminals, thus amplitude
modulating the RF field according to the memory data.
ACK
DC Output
twee
V
1 clocks per Bit and must be taken into
ACK
LIW
V4070
AC Input
Figure 12
Figure 14
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