AS3935-BQFT ams, AS3935-BQFT Datasheet - Page 11

• Manufacturer Part Number: AS3935-BQFT
• Description: Interface - Specialized
• Manufacturer: ams

Specifications of AS3935-BQFT

• Rohs: yes
• Operating Supply Voltage: 2.4 V to 5.5 V
• Supply Current: 100 mA
• Maximum Power Dissipation: 0.1 W
• Mounting Style: SMD/SMT
• Package / Case: MLPQ-16
• Supply Voltage - Max: 5.5 V

AS3935
Datasheet - D e t a i l e d D e s c r i p t i o n
8.1 Circuit
Figure 1
demodulates the received signal. The watchdog continuously monitors the output of the AFE and alerts the integrated lightning algorithm block in
the event of an incoming signal. The lightning algorithm block validates the signal by checking the incoming signal pattern, calculates the energy
and then the AS3935 provides the MCU with an estimate of the distance to the head of the storm. The lightning algorithm block, processing the
demodulated signal, can distinguish between lightning signal and man-made disturbers. If the received signal is classified as a man-made
disturber, then the event is rejected and the system automatically goes back into listening mode to minimize current consumption. If the incoming
signal identifies a lightning event, then the statistical distance estimation block performs an estimation of the distance to the head of the storm
(Typical time needed 2ms).
The LC oscillator together with the calibration block can calibrate both the TRCO and the SRCO clock generator to compensate process
variations.
8.2 Operating Modes
Power-down Mode.
In Power-down Mode, the entire AS3935 is switched off to reduce the current consumption to minimum (typ 1μA).
Listening Mode.
In listening mode the AFE, the watchdog, the noise floor level generation, the bias block, the TRCO, and the voltage regulator (in case it is
enabled) are running. In this mode the system can push down the power consumption to a minimum (typ 60μA). In case the maximum voltage
supply does not exceed 3.6V, it is possible to switch off the voltage regulator to save power.
Signal Verification.
The AS3935 enters in this mode every time the watchdog detects dynamic activity picked up by the antenna. Threshold can be set in WDTH
REG0x01[3:0]. The IC will leave this mode either if the incoming signal is classified as disturber or if the analysis of the single event (lightning) is
finished. If the received signal is classified as a disturber, then the AS3935 will automatically go back to listening mode without any needed
action from outside and an interrupt will be generated (with option bit this interrupt can be masked). If the received pattern matches all
requirements, the energy calculation is performed and the AS3935 provides distance estimation.
8.3 System and Block Specification
8.3.1 Register Table
Table 8. Register Table
www.austriamicrosystems.com
Register #
0x00
0x01
0x02
0x03
0x04
0x05
0x06
0x07
0x08
0x09
0x32
...
...
...
...
shows a block diagram of the AS3935. The external antenna is directly connected to the Analog Front-end (AFE), which amplifies and
DISP_LCO
Reserved
Reserved
7
LCO_FDIV
Reserved
Reserved
Reserved
DISP_SRCO
CL_STAT
6
DISP_TRCO
MASK_DIST
NF_LEV
5
MIN_NUM_LIGH
Lightning Detection Look-up Table
Revision 1.2
Reserved
Reserved
S_LIG_M
S_LIG_L
4
AFE_GB
3
DISTANCE
S_LIG_MM
2
TUN_CAP
WDTH
SREJ
INT
1
PWD
0
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