U9280M-H View Datasheet(PDF) - Atmel Corporation
Part Name
Description
Manufacturer
U9280M-H Datasheet PDF : 24 Pages
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U9280M-H
Figure 3-1. Block Diagram ATAR092
V SS V DD
OSC1 OSC2
BP10
BP13
BP20/NTE
BP21
BP22
BP23
Brown-out protect
RESET
Voltage monitor
External input
VMI
Port 1
RC
Crystal External
oscillators oscillators clock input
Clock management
ROM
4 K x 8-bit
RAM
256 x 4 bit
MARC4
4-bit CPU core
I/O bus
UTCM
Timer 1
interval- and
watchdog timer
Timer 2
T2I
8/12-bit timer T2O
with modulator
SD
SSI
SC
Serial interface
Timer 3
T3O
8-bit
timer / counter T3I
with modulator
and demodulator
Data direction +
alternate function
Port 4
Data direction +
interrupt control
Port 5
Data dir. +
alt. function
Port 6
BP40 BP42
BP50 BP52
INT3
T2O BP43 INT6 INT1
SC BP41
INT3
BP51 BP53
VMI
SD
INT6 INT1
T2I
BP60 BP63
T3O T3I
3.2 The U3280M Transponder Interface
The transponder interface contains a rectifier stage to rectify the AC from the coil inputs and to
supply itself and an additional microcontroller device with power from an LC-resonant circuit at
the coil inputs. It is also possible to supply the device via the VBatt -input with DC from a battery.
The built-in power management switches automatically between battery supply (VBatt pin) and
coil supply. It switches to coil supply if a field is applied at the coil and switches back to battery if
the field is removed.
The voltage from the coil or the VBatt pin is output at the VDD pin to supply the microcontroller
device. At the VDD pin a capacitor must be connected to smooth and buffer the supply voltage for
the transponder interface and the microcontroller. This capacitor is also used to buffer the supply
voltage during communication (damping and gaps in the field).
For communication, a damping-stage and a gap-detect circuitry is on the chip. By means of the
damping stage the coil voltage can be modulated to transmit data via the field. It can be con-
trolled with the modulator input (MOD pin) via the microcontroller. The gap detection circuitry
detects gaps in the field and outputs the gap/field signal at the gap detect output (NGAP pin). It
can be used to receive data via a modulated field and to check if a field is applied at the coil.
5
4591B–RFID–09/05
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