TMD2672 Datasheet, PDF (9/29 Pages) ams AG – DIGITAL PROXIMITY DETECTOR

TMD2672
DIGITAL PROXIMITY DETECTOR
TAOS149C − AUGUST 2012
PRINCIPLES OF OPERATION
System State Machine
An internal state machine provides system control of the proximity detection and power management features
of the device. At power up, an internal power-on-reset initializes the device and puts it in a low-power Sleep
state.
When a start condition is detected on the I²C bus, the device transitions to the Idle state where it checks the
Enable register (0x00) PON bit. If PON is disabled, the device will return to the Sleep state to save power.
Otherwise, the device will remain in the Idle state until a proximity function is enabled. Once enabled, the device
lid ^{will execute the Prox and Wait states in sequence as indicated in Figure 6. Upon completion and return to Idle,}
the device will automatically begin a new prox-wait cycle as long as PON and PEN are enabled.
If the Prox function generates an interrupt and the Sleep-After-Interrupt (SAI) feature is enabled the device will
a _{transition to the Sleep state and remain in a low-power mode until an I2C command is received. See the}
v ^{Interrupts section for additional information.}
ill ^Sleep
I²C
Start
!PON
G _{st INT & SAI}
Idle
PEN
ms ^{A tent} _Prox
!WEN
!PEN &
WEN
a _{l con WEN}
Wait
Technica^{Figure 6. Simplified State Diagram}
Copyright E 2012, TAOS Inc.
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