TMD37823 Datasheet, PDF (18/34 Pages) TEXAS ADVANCED OPTOELECTRONIC SOLUTIONS – Color Light-To-Digital Converter with Proximity Sensing

System Timing
Figure TMD3782 – 26:
Enhanced State Machine Diagram
The system state machine shown in Figure TMD3782 - 26
provides an overview of the states and state transitions that
provide system control of the device. This section highlights the
programmable features, which affect the state machine cycle
time, and provides details to determine system level timing.
When the proximity detection feature is enabled (PEN), the
state machine transitions through the Prox Accum, Prox Wait,
and Prox ADC states. The Prox Wait time is a fixed 2.4 ms,
whereas the Prox Accum time is determined by the number of
proximity LED pulses (PPULSE) and the Prox ADC time is
determined by the integration time (PTIME). The formulas to
determine the Prox Accum and Prox ADC times are given in the
associated boxes in Figure TMD3782 - 26. If an interrupt is
generated as a result of the proximity cycle, it will be asserted
at the end of the Prox ADC state.
When the power management feature is enabled (WEN), the
state machine will transition in turn to the Wait state. The wait
time is determined by WLONG, which extends normal operation
by 12× when asserted, and WTIME. The formula to determine
the wait time is given in the box associated with the Wait state
in Figure TMD3782 - 26.
When the RGBC feature is enabled (AEN), the state machine will
transition through the RGBC Init and RGBC ADC states. The
RGBC Init state takes 2.4 ms, while the RGBC ADC time is
dependent on the integration time (ATIME). The formula to
determine RGBC ADC time is given in the associated box in
Figure TMD3782 - 26. If an interrupt is generated as a result of
the RGBC cycle, it will be asserted at the end of the RGBC ADC.
Notes:
1. There is a 2.4 ms warm-up delay if PON is enabled. If PON is not enabled, the device will return to the Sleep state as shown.
2. PON, PEN, WEN and AEN are fields in the Enable register (0x00).
3. PON=1, PEN-1, WEN-1, AEN=0 is unsupported and will lead to erroneous proximity readings.
TMD3782 – 18
Datasheet - Mar. 2013 - V2