ATA5279 ATMEL Corporation, ATA5279 Datasheet - Page 24

• Manufacturer Part Number: ATA5279
• Manufacturer: ATMEL Corporation

24
ATA5279 [Preliminary]
Figure 3-16. LF Data Processing
• Send LF Carrier:
SPi Data String (hex)
SPi Data String (bin)
This command should be used when a carrier shall be transmitted on the LF channel via the
selected coil. The current will be regulated by ATA5279 to the value selected with the last
Select Coil Current command (resp. the default value of 50 mA). See also
Current Sensing (Zero Cross, Sample and Hold, Integrator)” on page 8
The duration of this carrier can be defined by the T
LF data bit, i.e., 32 LF periods in normal- and 22 LF periods in high-speed mode. That leads
to a maximum definable carrier time per command of 31
an 8 MHz system clock.
However, when the T
selected current on the actually active coil is started. This can be used for long-term
measurements or for energy-coupling purposes. Be aware that long-term transmissions can
produce a huge amount of heat in the driver, dependant on the selected coil current and the
properties of the coil itself. It is therefore strongly recommended to use this feature only with
a maximum current settings of 100 mA; otherwise, a thermal shutdown may occur and
interrupt the field.
MACT Signal
BCNT Signal
LF Telegram
0000 0010
4..0
-value is set to 0, an endless carrier transmission with the actually
02h
0
0
1
35h
1
0
4..0
1
0
bits. Note that the time unit here is one
1
0.256 ms = 7.936 ms when using
for further details.
Section 3.5 “Coil
9125A–RKE–04/08
0
04h
1
0
0