ATA5283 ATMEL Corporation, ATA5283 Datasheet - Page 7

• Manufacturer Part Number: ATA5283
• Description: Interface ic For 125 KHZ Wake-up Function
• Manufacturer: ATMEL Corporation

Reset
Standby Listen Mode
Applications
Figure 8. Application
4598A–AUTO–04/03
Central
Board
Controller
UHF
Receiver
T5760
Driver
Antenna
ATA5275
The IC is reset either by the internal POR circuit during a power on sequence or by a
high pulse at the RESET pin. After the reset all internal counters are in the initial state
and the IC is in the standby listen mode.
The POR circuit generates a reset while the supply voltage V
reset threshold V
A high signal at the RESET pin resets the complete circuit. If the IC is activated a reset
signal is necessary to activate the standby listen mode.
The RESET pin can also be used to hold the IC in a power down state. In this state the
the IC is out of operation and the current consumption is below the standby current.
Note:
In the standby listen mode the IC monitors the coil input with a very low current con-
sumption. The automatic gain control is switched off and the gain is set to the maximum
value. The N_DATA and the N_WAKEUP output are set to a high level.
Before the controller enters its standby mode after the communication, it should activate
the standby listen mode of the ATA5283 with a reset signal. This measure ensures that
the IC enters the power saving standby mode and that the IC wakes the controller cor-
rectly with the next preamble signal.
Figure 8 shows a typical TPM application of the ATA5283. Combined with the antenna
resonant circuit the ATA5283 is used as wake-up receiver for the microcontroller and
the connected temperature- and pressure-sensor.
Note:
125 kHz
433 MHz
The RESET pin is high impedance CMOS input. To avoid floating effects like undefined
input states and malfunctions it should not be open.
To avoid supply voltage ripples to affect the microcontroller, an RC filter (R1 = 100 W,
C1 = 10 nF) is recommended.
LA CA
POR
Amplifier
Vref
and release the function of the IC if V
AGC
with
UHF
Modul
T5750
VDD
ò
GND
ATA5283
RESET
N_WAKEUP
RESET
N_DATA
C1
R1
Micro
controller
MARC4
DD
exceeds this threshold.
DD
is below the power on
ATA5283
Pressure
Sensor
Sensor
Temp.
7