AS3932-BQFT austriamicrosystems, AS3932-BQFT Datasheet - Page 25

• Manufacturer Part Number: AS3932-BQFT
• Description: IC RF PROGRAM 16-QFN
• Manufacturer: austriamicrosystems

Specifications of AS3932-BQFT

• Rf Type: Read / Write
• Frequency: 110kHz ~ 150kHz
• Features: RSSI Equipped
• Package / Case: 16-VFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: AS3932-BQFTTR

AS3932
Datasheet - D e t a i l e d D e s c r i p t i o n
In case the data correlation is disabled (R1<1>=0) the AS3932 wakes up upon detection of the carrier frequency only as shown in
order to ensure that AS3932 wakes up the carrier burst has to last longer than 550 µs. To set AS3932 back to listening mode there are two
possibilities: either the microcontroller sends the direct command clear_wake via SDI or the time out option is used (R7<7:5>). In case the latter
is chosen, AS3932 is automatically set to listening mode after the time defined in T_OUT (R7<7:5>), counting starts at the low-to-high WAKE
edge on the WAKE pin.
8.6.2 Single Pattern Detection (Manchester decoder disabled)
The
burst has to be longer than 550 µs and can last maximum 16 bits (see bit rate definition in
minimum value of the maximum carrier burst duration is limited to 10 ms. This is summarized in
internal wakeup will be set back to low and the false wakeup counter (R13<7:0>) will be incremented by one. The carrier burst must be followed
by a preamble (0101... modulated carrier with a bit duration defined in
R6<7:0>. The preamble must have at least 4 bits and the preamble duration together with the pattern should not be longer than 40 bits. If the
wakeup pattern is correct, the signal on the WAKE pin goes high one bit after the end of the pattern and the data transmission can get started. To
set the chip back to listening mode the direct command clear_false, as well as the time out option (R7<7:5>) can be used.
Figure 20. Wakeup Protocol Overview with Single Pattern Detection (Manchester decoder disabled)
Table 22. Preamble Requirements in Standard Mode, Scanning Mode and ON/OFF Mode
www.austriamicrosystems.com/LF-Receiver/AS3932
Clear_wake
Bit rate (bit/s)
Figure 20
WAKE
DAT
8192
6552
5460
4680
4096
3640
Carrier Burst < 16 bit duration
shows the wakeup protocol in case the pattern correlation is enabled (R1<1>=1) for a 125 kHz carrier frequency. The initial carrier
Carrier Burst > 550 µs
Carrier Burst
Maximum duration of the carrier burst in Standard
1 bit Preamble
Mode and Scanning Mode (ms)
Preamble > 4 bit duration
Preamble + Pattern < 40 bit duration
1 bit Preamble
Preamble
1.95
2.44
2.93
3.41
3.90
4.39
Revision 1.4
Table
19) and the wakeup pattern stored in the registers R5<7:0> and
Pattern
Maximum duration of the carrier burst in ON/OFF Mode
Table
19). If the ON/OFF mode is used (R1<5>=1), the
Table
22. In case the carrier burst is too long the
(ms)
Data
10
10
10
10
10
10
Figure
25 - 36
19. In