MLX74190 Datasheet, PDF (7/14 Pages) Melexis Microelectronic Systems – Two-Fold High Power LF Initiator With integrated Immobilizer

3 Operating Modes
MLX74190
Two-Fold High Power LF Initiator
With integrated Immobilizer
Supply OFF
VDD >
(VDD_uvth + Vdd_uv_hys)
START
SLEEP
Time-out (SPI or Prg)
OR
Command “Go To
Sleep”
OR
VDD < VDD_uvth
OR
Falling edge on WUP
OR
PLL Unlock
FROM ANY
STATE
ACTIVE
TRANSMISSION
Stays in the loop if SPI command
received
Ready to Transmit
End of Transmission
OR
Command “Go To
Standby”
OR
Over-Temperature
OR
VS < VS_uvth
OR
Transmission aborted
STAND-BY
Stays in the loop if SPI
command received
Direct command
“Trigger diagnosis”
End of Diagnosis
OR
Command “Go To
Standby”
OR
Over-temperature
OR
VS < VS_uvth
DIAGNOSIS
Stays in the loop if SPI command
received
Figure 3: MLX74190 operating modes transition diagram
3.1 Sleep Mode
In SLEEP mode, all internal registers are set to their default values, flags and pointer are reset. All antenna
outputs are switched to Hi-Z mode, the PLL is switched OFF and the SPI interface is deactivated. The device
exits SLEEP mode when a rising edge is applied on the pin WUP by the external host MCU.
3.2 Standby Mode
In STANDBY mode, all antenna outputs are switched to Hi-Z mode, all digital outputs are switched to their
default values and the internal LF transmission chain is deactivated. The SPI interface is activated and the
MLX74190 device is able to receive and answer SPI commands from the external host MCU.
3.3 Transmission Mode
In TRANSMISSION mode, the MLX74190 is busy transmitting LF sequence(s). All digital outputs are active;
the LF driver outputs are configured according to the configuration register active. The SPI interface is
activated and the MLX74190 device is able to receive and answer SPI commands from the external host
MCU.
3.4 Diagnosis Mode
In DIAGNOSIS mode, the MLX74190 is busy with diagnosis procedure. All digital outputs are set in default
states; the LF driver outputs are activated and ready for diagnosis process. The SPI interface is activated and
the MLX74190 device is able to receive SPI command from the external host MCU.
390107419001
Rev. 001
Page 7 of 14
Product Preview
Sept-2014