ata5277-pcq ATMEL Corporation, ata5277-pcq Datasheet - Page 5

• Manufacturer Part Number: ata5277-pcq
• Description: Stand-alone Antenna Driver
• Manufacturer: ATMEL Corporation

4669B–RKE–10/03
Figure 3. Wake-up by External Switch
In Figure 3, the IC is woken up by an external switch (pulled to ground). After a
debouncing time t
nected microcontroller via the DIO line. Note that this impulse is already the start bit of
the first command. After that, the ATA5277 waits for a control or status command from
the microcontroller. The carrier remains off as the configuration bit M_Wake (see control
command 2) is '0'.
Figure 4. Wake-up by External Switch, Automatic Field Generation
The wake-up event as shown in Figure 4 is the same as in Figure 3, except for the con-
figuration bit M_Wake which is '1'. The driver stage will start operation after the wake-up
command has been confirmed. This behaviour can be used to build up an LF field inde-
pendently of the connected microcontroller.
Figure 5. Wake-up by Connected Microcontroller, Automatic Field Generation
Figure 5 shows a wake-up event triggered by the connected microcontroller, which now
pulls the DIO line to ground. To prevent the ATA5277 from waking up due to noise on
the DIO line, there is also a debouncing time before it will start operation. In this exam-
ple, M_Wake is again '1', so the driver stage starts operation after the wake-up event
has been confirmed.
DIO line
DIO line
DIO line
Carrier state
Carrier state
Carrier state
Ext. switch
Ext. switch
Ext. switch
deb
, the IC leaves sleep mode and sends a wake-up impulse to a con-
t
deb
t
t
deb
deb
t
t
t
ATA5277 [Preliminary]
wake
wake
wake
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